Single-photon driven high-order sideband transitions in an ultrastrongly coupled circuit quantum electrodynamics system

NASA Astrophysics Data System (ADS)

Li, Tiefu; Chen, Zhen; Wang, Yimin; Tian, Lin; Qiu, Yueyin; Inomata, Kunihiro; Yoshihara, Fumiki; Han, Siyuan; Nori, Franco; Tsai, Jaw-Shen; You, J. Q.

We report the experimental observation of high-order sideband transitions at the single-photon level in a quantum circuit system of a flux qubit ultrastrongly coupled to a coplanar waveguide resonator. With the coupling strength reaching 10 % of the resonator's fundamental frequency, we obtain clear signatures of higher-order red- and first-order blue-sideband transitions. These transitions are owing to the ultrastrong Rabi coupling, instead of the driving power. Our observation advances the understanding of ultrastrongly-coupled systems and paves the way to study high-order processes in the quantum Rabi model. This work is supported by the National Basic Research Program of China and the National Natural Science Foundation of China.

Multiphoton dynamics of qutrits in the ultrastrong coupling regime with a quantized photonic field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Avetissian, H. K., E-mail: avetissian@ysu.am; Avetissian, A. K.; Mkrtchian, G. F.

2015-12-15

Multiphoton resonant excitation of a three-state quantum system (a qutrit) with a single-mode photonic field is considered in the ultrastrong coupling regime, when the qutrit–photonic field coupling rate is comparable to appreciable fractions of the photon frequency. For ultrastrong couplings, the obtained solutions of the Schrödinger equation that reveal multiphoton Rabi oscillations in qutrits with the interference effects leading to the collapse and revival of atomic excitation probabilities at the direct multiphoton resonant transitions.

Ultrafast quantum computation in ultrastrongly coupled circuit QED systems.

PubMed

Wang, Yimin; Guo, Chu; Zhang, Guo-Qiang; Wang, Gangcheng; Wu, Chunfeng

2017-03-10

The latest technological progress of achieving the ultrastrong-coupling regime in circuit quantum electrodynamics (QED) systems has greatly promoted the developments of quantum physics, where novel quantum optics phenomena and potential computational benefits have been predicted. Here, we propose a scheme to accelerate the nontrivial two-qubit phase gate in a circuit QED system, where superconducting flux qubits are ultrastrongly coupled to a transmission line resonator (TLR), and two more TLRs are coupled to the ultrastrongly-coupled system for assistant. The nontrivial unconventional geometric phase gate between the two flux qubits is achieved based on close-loop displacements of the three-mode intracavity fields. Moreover, as there are three resonators contributing to the phase accumulation, the requirement of the coupling strength to realize the two-qubit gate can be reduced. Further reduction in the coupling strength to achieve a specific controlled-phase gate can be realized by adding more auxiliary resonators to the ultrastrongly-coupled system through superconducting quantum interference devices. We also present a study of our scheme with realistic parameters considering imperfect controls and noisy environment. Our scheme possesses the merits of ultrafastness and noise-tolerance due to the advantages of geometric phases.

Ultrafast quantum computation in ultrastrongly coupled circuit QED systems

PubMed Central

Wang, Yimin; Guo, Chu; Zhang, Guo-Qiang; Wang, Gangcheng; Wu, Chunfeng

2017-01-01

The latest technological progress of achieving the ultrastrong-coupling regime in circuit quantum electrodynamics (QED) systems has greatly promoted the developments of quantum physics, where novel quantum optics phenomena and potential computational benefits have been predicted. Here, we propose a scheme to accelerate the nontrivial two-qubit phase gate in a circuit QED system, where superconducting flux qubits are ultrastrongly coupled to a transmission line resonator (TLR), and two more TLRs are coupled to the ultrastrongly-coupled system for assistant. The nontrivial unconventional geometric phase gate between the two flux qubits is achieved based on close-loop displacements of the three-mode intracavity fields. Moreover, as there are three resonators contributing to the phase accumulation, the requirement of the coupling strength to realize the two-qubit gate can be reduced. Further reduction in the coupling strength to achieve a specific controlled-phase gate can be realized by adding more auxiliary resonators to the ultrastrongly-coupled system through superconducting quantum interference devices. We also present a study of our scheme with realistic parameters considering imperfect controls and noisy environment. Our scheme possesses the merits of ultrafastness and noise-tolerance due to the advantages of geometric phases. PMID:28281654

Nonlinear optics in organic cavity polaritons (Conference Presentation)

NASA Astrophysics Data System (ADS)

Singer, Kenneth D.; Liu, Bin; Crescimanno, Michael; Twieg, Robert J.

2017-02-01

Coupling between excitons belonging to organic dyes and photons in a microcavities forming cavity polaritons have been receiving attention for their fundamental interest as well as potential applications in coherent light sources. Organic materials are of particular interest as the coupling is particularly strong due to the large oscillator strength of conjugated organic molecules. The resulting coupling in organic materials is routinely in the strong regime. Ultrastrong coupling between photons and excitons in microcavities containing organic dyes and semiconductors has been recently observed in room temperature. We have studied the coupling between cavity pairs in the ultrastrong regime and found that the high order terms in the modified Jaynes-Cummings model result in broken degeneracy between the symmetric and antisymmetric modes. The unusually strong coupling between cavity photons and organic excitons dovetail with the robust nonlinear optical responses of the same materials. This provides a new and promising hybrid material for photonics. We report on measurements of photorefraction in organic cavities containing a derivative of the photorefractive organic glass based on 2-dicyanomethylene-3-cyano-2,5-dihydrofuran (DCDHF).

Low-voltage polariton electroluminescence from an ultrastrongly coupled organic light-emitting diode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gubbin, Christopher R.; Maier, Stefan A.; Kéna-Cohen, Stéphane, E-mail: s.kena-cohen@polymtl.ca

2014-06-09

We demonstrate electroluminescence from Frenkel molecular excitons ultrastrongly coupled to photons of a metal-clad microcavity containing a 2,7-bis[9,9-di(4-methylphenyl)-fluoren-2-yl]-9,9-di(4-methylphenyl)fluorene emissive layer. Thin layers of molybdenum oxide and 4,7-diphenyl-1,10-phenanthroline are used as hole and electron injection layers, respectively. The fabricated devices exhibit an electroluminescence threshold of 3.1 V, a value that is below the bare exciton energy. This result is found to be independent of detuning and consistent with a two-step process for polariton formation. Moreover, we investigate the quantum efficiency of carrier to polariton to photon conversion and obtain an external quantum efficiency of 0.1% for the fabricated structures, an improvement ofmore » 5 orders of magnitude over previous reports.« less

Spin-1 models in the ultrastrong-coupling regime of circuit QED

NASA Astrophysics Data System (ADS)

Albarrán-Arriagada, F.; Lamata, L.; Solano, E.; Romero, G.; Retamal, J. C.

2018-02-01

We propose a superconducting circuit platform for simulating spin-1 models. To this purpose we consider a chain of N ultrastrongly coupled qubit-resonator systems interacting through a grounded superconducting quantum interference device (SQUID). The anharmonic spectrum of the qubit-resonator system and the selection rules imposed by the global parity symmetry allow us to activate well controlled two-body quantum gates via ac pulses applied to the SQUID. We show that our proposal has the same simulation time for any number of spin-1 interacting particles. This scheme may be implemented within the state-of-the-art circuit QED in the ultrastrong coupling regime.

Multi-mode ultra-strong coupling (I): spectroscopic experiments using a vacuum-gap transmon circuit architecture

NASA Astrophysics Data System (ADS)

Bosman, Sal J.; Gely, Mario F.; Singh, Vibhor; Bruno, Alessandro; Bothner, Daniel; Steele, Gary A.

In circuit QED, multi-mode extensions of the quantum Rabi model suffer from divergence problems. Here, we spectroscopically study multi-mode ultra-strong coupling using a transmon circuit architecture, which provides no clear guidelines on how many modes play a role in the dynamics of the system. As our transmon qubit, we employ a suspended island above the voltage anti-node of a λ / 4 coplanar microwave resonator, thereby realising a circuit where 88% of the qubit capacitance is formed by a vacuum-gap capacitor with the center conductor of the resonator. We measure vacuum Rabi splitting over multiple modes up to 2 GHz, reaching coupling ratios of g / ω = 0 . 18 , well within the ultra-strong coupling regime. We observe a qubit-mediated mode coupling, measurable up to the fifth mode at 38 GHz. Using a novel analytical quantum circuit model of this architecture, which includes all modes without introducing divergencies, we are able to fit the full spectrum and extract a vacuum fluctuations induced Bloch-Siegert shift of up to 62 MHz. This circuit architecture expands the versatility of the transmon technology platform and opens many possibilities in multi-mode physics in the ultra-strong coupling regime.

Harmonic generation with an ultra-strongly coupled cavity polariton

NASA Astrophysics Data System (ADS)

Crescimanno, Michael; Singer, Kenneth; Liu, Bin; McMaster, Michael

2017-04-01

The large dipole density in a new class of glassy organic dyes results in ultrastrong exciton-cavity field coupling leading to polariton splittings of over an eV. We describe the theoretical model and experimental protocol used to understand third harmonic generation (THG) in this system. We quantify the THG enhancement at the polariton branches through its dependence on coupling, cavity-exciton detuning and cavity finesse.

Ultrastrong coupling in supersymmetric gauge theories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buchel, Alex

1999-10-04

We study 'ultrastrong' coupling points in scale-invariant N=2 gauge theories. These are theories where, naively, the coupling becomes infinite, and is not related by S-duality to a weak coupling point. These theories have been somewhat of a mystery, since in the M-theory description they correspond to points where parallel M 5-branes coincide. Using the low-energy effective field theory arguments we relate these theories to other known N=2 CFT.

Protected Quantum Computation with Multiple Resonators in Ultrastrong Coupling Circuit QED

NASA Astrophysics Data System (ADS)

Nataf, Pierre; Ciuti, Cristiano

2011-11-01

We investigate theoretically the dynamical behavior of a qubit obtained with the two ground eigenstates of an ultrastrong coupling circuit-QED system consisting of a finite number of Josephson fluxonium atoms inductively coupled to a transmission line resonator. We show a universal set of quantum gates by using multiple transmission line resonators (each resonator represents a single qubit). We discuss the intrinsic “anisotropic” nature of noise sources for fluxonium artificial atoms. Through a master equation treatment with colored noise and many-level dynamics, we prove that, for a general class of anisotropic noise sources, the coherence time of the qubit and the fidelity of the quantum operations can be dramatically improved in an optimal regime of ultrastrong coupling, where the ground state is an entangled photonic “cat” state.

Ionization, photoelectron dynamics and elastic scattering in relativistic, ultra-strong field

NASA Astrophysics Data System (ADS)

Luo, Sui

Ultrastrong laser-matter interaction has direct bearing to next generation technologies including plasma acceleration, laser fusion and attosecond X-ray generation. The commonly known physics in strong field becomes different as one progress to ultrastrong field. The works presented in this dissertation theoretically study the influence of relativistic effect and magnetic component of the laser field on the ionization, photoelectron dynamics and elastic scattering processes. The influence of magnetic component (B laser) of circularly polarized (CP) ultrastrong fields (up to3 x 1022 W/cm2) on atomic bound state dynamics is investigated. The Poincare plots are used to find the changes in trajectory energies are on the order of a few percent for intensities up to1 x 1022 W/cm2. It is found that at intensities where ionization approaches 50% for the bound state, the small changes from Blaser of the circular polarized light can actually result in a several-fold decrease in ionization probability. The force on the bound electron exerted by the Lorentz force from B laser is perpendicular to the rotating plane of the circular polarized light, and this nature makes those trajectories which are aligned away from the minimum in the potential barrier stabilized against tunneling ionization. Our results provide a classical understanding for ionization in ultrastrong fields and indicate that relativistic effects in ultrastrong field ionization may most easily be seen with CP fields. The photoelectron energy spectra from elastic rescattering in ultrastrong laser fields (up to 2x1019 W/cm2) is studied by using a relativistic adaption of a semi-classical three-step recollision model. The Hartree-Fock scattering potentials are used in calculating the elastic rescattering for both hydrogenlike and noble gas species. It is found that there is a reduction in elastic rescattering for intensities beyond 6 x 1016 W/cm2 when the laser Lorentz deflection of the photoelectron exceeds its wave-function spread. A relativistic rescattering enhancement occurs at 2 x 1018 W/cm2, commensurate with relativistic motion of a classical electron in a single field cycle. The good comparison between the results with available experiments suggests the theory approach is well suited to modeling scattering in the ultrastrong intensity regime. We investigate the elastic scattering process as it changes from strong to ultrastrong fields with the photoelectron angular distributions from Ne, Ar, and Xe. Noble gas species with Hartree-Fock scattering potentials show a reduction in elastic rescattering with the increasing energy of ultrastrong fields. It is found that as one increases the returning photoelectron energy, rescattering becomes the dominating mechanism behind the yield distribution as the emission angle for all the species extends from 0° to 90°. The relativistic effects and the magnetic field do not change the angular distribution until one is well into the Gamma r "1 regime where the Lorentz defection significantly reduces the yield. As we proceed to the highest energy, the angular emission range narrows as the mechanism changes over to backscattering into narrow angles along the electric field.

Long-lasting quantum memories: Extending the coherence time of superconducting artificial atoms in the ultrastrong-coupling regime

NASA Astrophysics Data System (ADS)

Stassi, Roberto; Nori, Franco

2018-03-01

Quantum systems are affected by interactions with their environments, causing decoherence through two processes: pure dephasing and energy relaxation. For quantum information processing it is important to increase the coherence time of Josephson qubits and other artificial two-level atoms. We show theoretically that if the coupling between these qubits and a cavity field is longitudinal and in the ultrastrong-coupling regime, the system is strongly protected against relaxation. Vice versa, if the coupling is transverse and in the ultrastrong-coupling regime, the system is protected against pure dephasing. Taking advantage of the relaxation suppression, we show that it is possible to enhance their coherence time and use these qubits as quantum memories. Indeed, to preserve the coherence from pure dephasing, we prove that it is possible to apply dynamical decoupling. We also use an auxiliary atomic level to store and retrieve quantum information.

A mathematical analysis of dressed photon in ground state of generalized quantum Rabi model using pair theory

NASA Astrophysics Data System (ADS)

Hirokawa, Masao; Møller, Jacob S.; Sasaki, Itaru

2017-05-01

We consider the generalized quantum Rabi model with the so-called A 2-term in the light of the Hepp-Lieb-Preparata quantum phase transition. We investigate the dressed photon in its ground state when the atom-light coupling strength is in the deep-strong coupling regime. This regime is introduced by Casanova et al (2010 Phys. Rev. Lett. 105 263603) as the coupling regime exceeding the ultra-strong one. We show how the dressed photon appears in the ground state. We dedicate this paper to Pavel Exner and Herbert Spohn on the occasion of their 70th birthdays, and Klaus Hepp on the occasion of his 80th birthday.

Continuous transition between weak and ultrastrong coupling through exceptional points in carbon nanotube microcavity exciton-polaritons

NASA Astrophysics Data System (ADS)

Gao, Weilu; Li, Xinwei; Bamba, Motoaki; Kono, Junichiro

2018-06-01

Non-perturbative coupling of photons and excitons produces hybrid particles, exciton-polaritons, which have exhibited a variety of many-body phenomena in various microcavity systems. However, the vacuum Rabi splitting (VRS), which defines the strength of photon-exciton coupling, is usually a single constant for a given system. Here, we have developed a unique architecture in which excitons in an aligned single-chirality carbon nanotube film interact with cavity photons in polarization-dependent manners. The system reveals ultrastrong coupling (VRS up to 329 meV or a coupling-strength-to-transition-energy ratio of 13.3%) for polarization parallel to the nanotube axis, whereas VRS is absent for perpendicular polarization. Between these two extremes, VRS is continuously tunable through polarization rotation with exceptional points separating crossing and anticrossing. The points between exceptional points form equienergy arcs onto which the upper and lower polaritons coalesce. The demonstrated on-demand ultrastrong coupling provides ways to explore topological properties of polaritons and quantum technology applications.

Deterministic quantum nonlinear optics with single atoms and virtual photons

NASA Astrophysics Data System (ADS)

Kockum, Anton Frisk; Miranowicz, Adam; Macrı, Vincenzo; Savasta, Salvatore; Nori, Franco

2017-06-01

We show how analogs of a large number of well-known nonlinear-optics phenomena can be realized with one or more two-level atoms coupled to one or more resonator modes. Through higher-order processes, where virtual photons are created and annihilated, an effective deterministic coupling between two states of such a system can be created. In this way, analogs of three-wave mixing, four-wave mixing, higher-harmonic and -subharmonic generation (i.e., up- and down-conversion), multiphoton absorption, parametric amplification, Raman and hyper-Raman scattering, the Kerr effect, and other nonlinear processes can be realized. In contrast to most conventional implementations of nonlinear optics, these analogs can reach unit efficiency, only use a minimal number of photons (they do not require any strong external drive), and do not require more than two atomic levels. The strength of the effective coupling in our proposed setups becomes weaker the more intermediate transition steps are needed. However, given the recent experimental progress in ultrastrong light-matter coupling and improvement of coherence times for engineered quantum systems, especially in the field of circuit quantum electrodynamics, we estimate that many of these nonlinear-optics analogs can be realized with currently available technology.

Ultrastrong Coupling Few-Photon Scattering Theory

NASA Astrophysics Data System (ADS)

Shi, Tao; Chang, Yue; García-Ripoll, Juan José

2018-04-01

We study the scattering of individual photons by a two-level system ultrastrongly coupled to a waveguide. The scattering is elastic for a broad range of couplings and can be described with an effective U (1 )-symmetric Hamiltonian. This simple model allows the prediction of scattering resonance line shapes, validated up to α =0.3 , and close to the Toulouse point α =1 /2 , where inelastic scattering becomes relevant. Our predictions model experiments with superconducting circuits [P. Forn-Díaz et al., Nat. Phys. 13, 39 (2017), 10.1038/nphys3905] and can be extended to study multiphoton scattering.

Ultrastrong Coupling Few-Photon Scattering Theory.

PubMed

Shi, Tao; Chang, Yue; García-Ripoll, Juan José

2018-04-13

We study the scattering of individual photons by a two-level system ultrastrongly coupled to a waveguide. The scattering is elastic for a broad range of couplings and can be described with an effective U(1)-symmetric Hamiltonian. This simple model allows the prediction of scattering resonance line shapes, validated up to α=0.3, and close to the Toulouse point α=1/2, where inelastic scattering becomes relevant. Our predictions model experiments with superconducting circuits [P. Forn-Díaz et al., Nat. Phys. 13, 39 (2017)NPAHAX1745-247310.1038/nphys3905] and can be extended to study multiphoton scattering.

Analytical ground state for the Jaynes-Cummings model with ultrastrong coupling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Yuanwei; Institute of Theoretical Physics, Shanxi University, Taiyuan 030006; Chen Gang

2011-06-15

We present a generalized variational method to analytically obtain the ground-state properties of the Jaynes-Cummings model with the ultrastrong coupling. An explicit expression for the ground-state energy, which agrees well with the numerical simulation in a wide range of the experimental parameters, is given. In particular, the introduced method can successfully solve this Jaynes-Cummings model with the positive detuning (the atomic resonant level is larger than the photon frequency), which cannot be treated in the adiabatical approximation and the generalized rotating-wave approximation. Finally, we also demonstrate analytically how to control the mean photon number by means of the current experimentalmore » parameters including the photon frequency, the coupling strength, and especially the atomic resonant level.« less

Feynman-diagrams approach to the quantum Rabi model for ultrastrong cavity QED: stimulated emission and reabsorption of virtual particles dressing a physical excitation

NASA Astrophysics Data System (ADS)

Di Stefano, Omar; Stassi, Roberto; Garziano, Luigi; Frisk Kockum, Anton; Savasta, Salvatore; Nori, Franco

2017-05-01

In quantum field theory, bare particles are dressed by a cloud of virtual particles to form physical particles. The virtual particles affect properties such as the mass and charge of the physical particles, and it is only these modified properties that can be measured in experiments, not the properties of the bare particles. The influence of virtual particles is prominent in the ultrastrong-coupling regime of cavity quantum electrodynamics (QED), which has recently been realised in several condensed-matter systems. In some of these systems, the effective interaction between atom-like transitions and the cavity photons can be switched on or off by external control pulses. This offers unprecedented possibilities for exploring quantum vacuum fluctuations and the relation between physical and bare particles. We consider a single three-level quantum system coupled to an optical resonator. Here we show that, by applying external electromagnetic pulses of suitable amplitude and frequency, each virtual photon dressing a physical excitation in cavity-QED systems can be converted into a physical observable photon, and back again. In this way, the hidden relationship between the bare and the physical excitations can be unravelled and becomes experimentally testable. The conversion between virtual and physical photons can be clearly pictured using Feynman diagrams with cut loops.

Nonequilibrium and nonperturbative dynamics of ultrastrong coupling in open lines.

PubMed

Peropadre, B; Zueco, D; Porras, D; García-Ripoll, J J

2013-12-13

The time and space resolved dynamics of a qubit with an Ohmic coupling to propagating 1D photons is studied, from weak coupling to the ultrastrong coupling regime. A nonperturbative study based on matrix product states shows the following results, (i) The ground state of the combined systems contains excitations of both the qubit and the surrounding bosonic field. (ii) An initially excited qubit equilibrates through spontaneous emission to a state, which under certain conditions is locally close to that ground state, both in the qubit and the field. (iii) The resonances of the combined qubit-photon system match those of the spontaneous emission process and also the predictions of the adiabatic renormalization [A. J. Leggett et al., Rev. Mod. Phys. 59, 1 (1987)]. Finally, nonperturbative ab initio calculations show that this physics can be studied using a flux qubit galvanically coupled to a superconducting transmission line.

Probing the ultimate plasmon confinement limits with a van der Waals heterostructure.

PubMed

Alcaraz Iranzo, David; Nanot, Sébastien; Dias, Eduardo J C; Epstein, Itai; Peng, Cheng; Efetov, Dmitri K; Lundeberg, Mark B; Parret, Romain; Osmond, Johann; Hong, Jin-Yong; Kong, Jing; Englund, Dirk R; Peres, Nuno M R; Koppens, Frank H L

2018-04-20

The ability to confine light into tiny spatial dimensions is important for applications such as microscopy, sensing, and nanoscale lasers. Although plasmons offer an appealing avenue to confine light, Landau damping in metals imposes a trade-off between optical field confinement and losses. We show that a graphene-insulator-metal heterostructure can overcome that trade-off, and demonstrate plasmon confinement down to the ultimate limit of the length scale of one atom. This is achieved through far-field excitation of plasmon modes squeezed into an atomically thin hexagonal boron nitride dielectric spacer between graphene and metal rods. A theoretical model that takes into account the nonlocal optical response of both graphene and metal is used to describe the results. These ultraconfined plasmonic modes, addressed with far-field light excitation, enable a route to new regimes of ultrastrong light-matter interactions. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Ultra-strong coupling in a transmon circuit architecture

NASA Astrophysics Data System (ADS)

Bosman, Sal; Gely, Mario; Singh, Vibhor; Bruno, Alessandro; Steele, Gary

New unexplored phenomena are predicted in cQED for the ultra-strong coupling (USC) regime and beyond. Here, we explore two strategies to increase the coupling between a transmon qubit and a microwave resonator. In the first approach, we increase the impedance of the resonator, enhancing it's voltage zero-point fluctuations, and measure a vacuum Rabi splitting of 916 MHz. In a second approach, we create a transmon qubit by making a superconducting island suspended above the center conductor of the resonator and which is shorted to ground by two Josephson junctions. Doing so, we maximize the dipole moment of the qubit and observe a vacuum Rabi splitting of 1.2 GHz with a qubit linewidth of 1 MHz. This first transmon qubit in the USC regime improves the coherence time by a factor of 100 compared to other systems in the USC limit. Finally we predict that by combining both approaches, a coupling of ~ 3 . 6 GHz is possible, reaching close to the deep strong coupling limit. The work was supported by the Dutch science foundation NWO/FOM.

Biodegradable gold nanovesicles with an ultrastrong plasmonic coupling effect for photoacoustic imaging and photothermal therapy.

PubMed

Huang, Peng; Lin, Jing; Li, Wanwan; Rong, Pengfei; Wang, Zhe; Wang, Shouju; Wang, Xiaoping; Sun, Xiaolian; Aronova, Maria; Niu, Gang; Leapman, Richard D; Nie, Zhihong; Chen, Xiaoyuan

2013-12-23

The hierarchical assembly of gold nanoparticles (GNPs) allows the localized surface plasmon resonance peaks to be engineered to the near-infrared (NIR) region for enhanced photothermal therapy (PTT). Herein we report a novel theranostic platform based on biodegradable plasmonic gold nanovesicles for photoacoustic (PA) imaging and PTT. The disulfide bond at the terminus of a PEG-b-PCL block-copolymer graft enables dense packing of GNPs during the assembly process and induces ultrastrong plasmonic coupling between adjacent GNPs. The strong NIR absorption induced by plasmon coupling and very high photothermal conversion efficiency (η=37%) enable simultaneous thermal/PA imaging and enhanced PTT efficacy with improved clearance of the dissociated particles after the completion of PTT. The assembly of various nanocrystals with tailored optical, magnetic, and electronic properties into vesicle architectures opens new possibilities for the construction of multifunctional biodegradable platforms for biomedical applications. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Single-bubble sonoluminescence as Dicke superradiance at finite temperature

NASA Astrophysics Data System (ADS)

Aparicio Alcalde, M.; Quevedo, H.; Svaiter, N. F.

2014-12-01

Sonoluminescence is a process in which a strong sound field is used to produce light in liquids. We explain sonoluminescence as a phase transition from ordinary fluorescence to a superradiant phase. We consider a spin-boson model composed of a single bosonic mode and an ensemble of N identical two-level atoms. We assume that the whole system is in thermal equilibrium with a reservoir at temperature β-1. We show that, in a ultrastrong-coupling regime, between the two-level atoms and the electromagnetic field it is possible to have a cooperative interaction of the molecules of the gas in the interior of the bubble with the field, generating sonoluminescence.

Tailoring light-matter coupling in semiconductor and hybrid-plasmonic nanowires

PubMed Central

Piccione, Brian; Aspetti, Carlos O.; Cho, Chang-Hee; Agarwal, Ritesh

2014-01-01

Understanding interactions between light and matter is central to many fields, providing invaluable insights into the nature of matter. In its own right, a greater understanding of light-matter coupling has allowed for the creation of tailored applications, resulting in a variety of devices such as lasers, switches, sensors, modulators, and detectors. Reduction of optical mode volume is crucial to enhancing light-matter coupling strength, and among solid-state systems, self-assembled semiconductor and hybrid-plasmonic nanowires are amenable to creation of highly-confined optical modes. Following development of unique spectroscopic techniques designed for the nanowire morphology, carefully engineered semiconductor nanowire cavities have recently been tailored to enhance light-matter coupling strength in a manner previously seen in optical microcavities. Much smaller mode volumes in tailored hybrid-plasmonic nanowires have recently allowed for similar breakthroughs, resulting in sub-picosecond excited-state lifetimes and exceptionally high radiative rate enhancement. Here, we review literature on light-matter interactions in semiconductor and hybrid-plasmonic monolithic nanowire optical cavities to highlight recent progress made in tailoring light-matter coupling strengths. Beginning with a discussion of relevant concepts from optical physics, we will discuss how our knowledge of light-matter coupling has evolved with our ability to produce ever-shrinking optical mode volumes, shifting focus from bulk materials to optical microcavities, before moving on to recent results obtained from semiconducting nanowires. PMID:25093385

Faraday effect in a short pulse propagating in a resonant medium under an ultra-strong magnetic field

NASA Astrophysics Data System (ADS)

Huang, J. G.; Slavcheva, G.; Hess, O.

2008-04-01

We propose a dynamical model for description of the nonlinear Faraday rotation experienced by a short pulse propagating in a resonant medium subject to an ultra-strong static magnetic field. Under the assumptions of a sufficiently strong external magnetic field, such that the Zeeman splitting of the quantum system energy levels is large compared to the linewidth of the optical transitions involved and the bandwidth of the incident light, the light effectively interacts with a two-level system. Our numerical simulations show that the Faraday effect under these conditions is significantly distinctive from the one caused by weak to moderately strong magnetic field. Nonlinear coherent effects such as inhomogeneous polarization rotation along the pulse duration and an onset of a circularly polarized stimulated emission and coherent ringing have been demonstrated. Some views on the experimental observation of the predicted phenomena are given.

Nonstandard Yukawa couplings and Higgs portal dark matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bishara, Fady; Brod, Joachim; Uttayarat, Patipan

We study the implications of non-standard Higgs Yukawa couplings to light quarks on Higgs-portal dark matter phenomenology. Saturating the present experimental bounds on up-quark, down-quark, or strange-quark Yukawa couplings, the predicted direct dark matter detection scattering rate can increase by up to four orders of magnitude. The effect on the dark matter annihilation cross-section, on the other hand, is subleading unless the dark matter is very light — a scenario that is already excluded by measurements of the Higgs invisible decay width. We investigate the expected size of corrections in multi-Higgs-doublet models with natural flavor conservation, the type-II two-Higgs-doublet model,more » the Giudice-Lebedev model of light quark masses, minimal flavor violation new physics models, Randall-Sundrum, and composite Higgs models. We find that an enhancement in the dark matter scattering rate of an order of magnitude is possible. In conclusion, we point out that a discovery of Higgs-portal dark matter could lead to interesting bounds on the light-quark Yukawa couplings.« less

Nonstandard Yukawa couplings and Higgs portal dark matter

DOE PAGES

Bishara, Fady; Brod, Joachim; Uttayarat, Patipan; ...

2016-01-04

We study the implications of non-standard Higgs Yukawa couplings to light quarks on Higgs-portal dark matter phenomenology. Saturating the present experimental bounds on up-quark, down-quark, or strange-quark Yukawa couplings, the predicted direct dark matter detection scattering rate can increase by up to four orders of magnitude. The effect on the dark matter annihilation cross-section, on the other hand, is subleading unless the dark matter is very light — a scenario that is already excluded by measurements of the Higgs invisible decay width. We investigate the expected size of corrections in multi-Higgs-doublet models with natural flavor conservation, the type-II two-Higgs-doublet model,more » the Giudice-Lebedev model of light quark masses, minimal flavor violation new physics models, Randall-Sundrum, and composite Higgs models. We find that an enhancement in the dark matter scattering rate of an order of magnitude is possible. In conclusion, we point out that a discovery of Higgs-portal dark matter could lead to interesting bounds on the light-quark Yukawa couplings.« less

Vacuum Bloch-Siegert shift in Landau polaritons with ultra-high cooperativity

NASA Astrophysics Data System (ADS)

Li, Xinwei; Bamba, Motoaki; Zhang, Qi; Fallahi, Saeed; Gardner, Geoff C.; Gao, Weilu; Lou, Minhan; Yoshioka, Katsumasa; Manfra, Michael J.; Kono, Junichiro

2018-06-01

A two-level system resonantly interacting with an a.c. magnetic or electric field constitutes the physical basis of diverse phenomena and technologies. However, Schrödinger's equation for this seemingly simple system can be solved exactly only under the rotating-wave approximation, which neglects the counter-rotating field component. When the a.c. field is sufficiently strong, this approximation fails, leading to a resonance-frequency shift known as the Bloch-Siegert shift. Here, we report the vacuum Bloch-Siegert shift, which is induced by the ultra-strong coupling of matter with the counter-rotating component of the vacuum fluctuation field in a cavity. Specifically, an ultra-high-mobility two-dimensional electron gas inside a high-Q terahertz cavity in a quantizing magnetic field revealed ultra-narrow Landau polaritons, which exhibited a vacuum Bloch-Siegert shift up to 40 GHz. This shift, clearly distinguishable from the photon-field self-interaction effect, represents a unique manifestation of a strong-field phenomenon without a strong field.

A versatile tunable microcavity for investigation of light-matter interaction

NASA Astrophysics Data System (ADS)

Mochalov, Konstantin E.; Vaskan, Ivan S.; Dovzhenko, Dmitriy S.; Rakovich, Yury P.; Nabiev, Igor

2018-05-01

Light-matter interaction between a molecular ensemble and a confined electromagnetic field is a promising area of research, as it allows light-control of the properties of coupled matter. The common way to achieve coupling is to place an ensemble of molecules or quantum emitters into a cavity. In this approach, light-matter coupling is evidenced by modification of the spectral response of the emitter, which depends on the strength of interaction between emitter and cavity modes. However, there is not yet a user-friendly approach that allows the study of a large number of different and replaceable samples in a wide optical range using the same resonator. Here, we present the design of such a device that can speed up and facilitate investigation of light-matter interaction ranging from weak to strong coupling regimes in ultraviolet-visible and infrared (IR) spectral regions. The device is based on a tunable unstable λ/2 Fabry-Pérot microcavity consisting of plane and convex mirrors that satisfy the plane-parallelism condition at least at one point of the curved mirror and minimize the mode volume. Fine tuning of the microcavity length is provided by a Z-piezopositioner in a range up to 10 μm with a step of several nm. This design makes a device a versatile instrument that ensures easy finding of optimal conditions for light-matter interaction for almost any sample in both visible and IR areas, enabling observation of both electronic and vibrational couplings with microcavity modes thus paving the way to investigation of various coupling effects including Raman scattering enhancement, modification of chemical reactivity rate, lasing, and long-distance nonradiative energy transfer.

Ultra-strong surface plasmon amplification characteristic of a spaser based on gold-silver core-shell nanorods

NASA Astrophysics Data System (ADS)

Zhang, Li; Zhou, Jun; Zhang, Haopeng; Jiang, Tao; Lou, Cibo

2015-03-01

We proposed an efficient spaser based on gold-silver core-shell nanorods (NRs) encapsulated by an outer silica shell doped with a gain medium. The optical characteristics of the spaser were numerically simulated based on the finite element method (FEM). The results showed that the localized surface plasmon resonance (LSPR) amplification characteristics of the spaser strongly depend on the thickness of silver shell, the aspect ratio of the inner gold NRs, and the polarization direction of the incident light. And, the maximum absolute value of optical cross-section of the spaser can reach 21,824 μm2, which is about 1115, 523, and 18 times higher than that of spasers based on the gold NRs, the silver NRs, and the silver-gold core-shell NRs, respectively. The ultra-strong surface plasmon amplification characteristics of the spaser have potential applications in optical information storage, high sensitivity biochemical sensing, and medical engineering.

One-dimensional polaritons with size-tunable and enhanced coupling strengths in semiconductor nanowires.

PubMed

van Vugt, Lambert K; Piccione, Brian; Cho, Chang-Hee; Nukala, Pavan; Agarwal, Ritesh

2011-06-21

Strong coupling of light with excitons in direct bandgap semiconductors leads to the formation of composite photonic-electronic quasi-particles (polaritons), in which energy oscillates coherently between the photonic and excitonic states with the vacuum Rabi frequency. The light-matter coherence is maintained until the oscillator dephases or the photon escapes. Exciton-polariton formation has enabled the observation of Bose-Einstein condensation in the solid-state, low-threshold polariton lasing and is also useful for terahertz and slow-light applications. However, maintaining coherence for higher carrier concentration and temperature applications still requires increased coupling strengths. Here, we report on size-tunable, exceptionally high exciton-polariton coupling strengths characterized by a vacuum Rabi splitting of up to 200 meV as well as a reduction in group velocity, in surface-passivated, self-assembled semiconductor nanowire cavities. These experiments represent systematic investigations on light-matter coupling in one-dimensional optical nanocavities, demonstrating the ability to engineer light-matter coupling strengths at the nanoscale, even in non-quantum-confined systems, to values much higher than in bulk.

One-dimensional polaritons with size-tunable and enhanced coupling strengths in semiconductor nanowires

PubMed Central

van Vugt, Lambert K.; Piccione, Brian; Cho, Chang-Hee; Nukala, Pavan; Agarwal, Ritesh

2011-01-01

Strong coupling of light with excitons in direct bandgap semiconductors leads to the formation of composite photonic-electronic quasi-particles (polaritons), in which energy oscillates coherently between the photonic and excitonic states with the vacuum Rabi frequency. The light-matter coherence is maintained until the oscillator dephases or the photon escapes. Exciton-polariton formation has enabled the observation of Bose-Einstein condensation in the solid-state, low-threshold polariton lasing and is also useful for terahertz and slow-light applications. However, maintaining coherence for higher carrier concentration and temperature applications still requires increased coupling strengths. Here, we report on size-tunable, exceptionally high exciton-polariton coupling strengths characterized by a vacuum Rabi splitting of up to 200 meV as well as a reduction in group velocity, in surface-passivated, self-assembled semiconductor nanowire cavities. These experiments represent systematic investigations on light-matter coupling in one-dimensional optical nanocavities, demonstrating the ability to engineer light-matter coupling strengths at the nanoscale, even in non-quantum-confined systems, to values much higher than in bulk. PMID:21628582

Ultrafast control of strong light-matter coupling

NASA Astrophysics Data System (ADS)

Lange, Christoph; Cancellieri, Emiliano; Panna, Dmitry; Whittaker, David M.; Steger, Mark; Snoke, David W.; Pfeiffer, Loren N.; West, Kenneth W.; Hayat, Alex

2018-01-01

We dynamically modulate strong light-matter coupling in a GaAs/AlGaAs microcavity using intense ultrashort laser pulses tuned below the interband exciton energy, which induce a transient Stark shift of the cavity polaritons. For 225-fs pulses, shorter than the cavity Rabi cycle period of 1000 fs, this shift decouples excitons and cavity photons for the duration of the pulse, interrupting the periodic energy exchange between photonic and electronic states. For 1500-fs pulses, longer than the Rabi cycle period, however, the Stark shift does not affect the strong coupling. The two regimes are marked by distinctly different line shapes in ultrafast reflectivity measurements—regardless of the Stark field intensity. The crossover marks the transition from adiabatic to diabatic switching of strong light-matter coupling.

Two-Photon Raman Gain in a Laser Driven Potassium Vapor

DTIC Science & Technology

1996-02-01

between light and matter becomes highly nonlinear and the light and matter strongly couple, the systems become much more difficult to understand both...theoretically and experimentally. One example of a strongly coupled, highly nonlinear system is the two-photon laser that is based on the two-photon

Towards strong light-matter coupling at the single-resonator level with sub-wavelength mid-infrared nano-antennas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malerba, M.; De Angelis, F., E-mail: francesco.deangelis@iit.it; Ongarello, T.

2016-07-11

We report a crucial step towards single-object cavity electrodynamics in the mid-infrared spectral range using resonators that borrow functionalities from antennas. Room-temperature strong light-matter coupling is demonstrated in the mid-infrared between an intersubband transition and an extremely reduced number of sub-wavelength resonators. By exploiting 3D plasmonic nano-antennas featuring an out-of-plane geometry, we observed strong light-matter coupling in a very low number of resonators: only 16, more than 100 times better than what reported to date in this spectral range. The modal volume addressed by each nano-antenna is sub-wavelength-sized and it encompasses only ≈4400 electrons.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitrofanov, Oleg; Han, Zhanghua; Ding, Fei

(THz) plasmonic double-metal resonators enable enhanced light-matter coupling by utilizing strong localization of the resonant field. The closed resonator design however restricts investigations of the light-matter interaction effects. We propose and demonstrate a method for spatial mapping and spectroscopic analysis of the internal resonant THz fields in plasmonic double-metal THz resonators. We use the aperture-type scanning near-field THz time-domain microscopy and the concept of image charges to probe the THz fields confined within the resonator. The experimental method opens doors to studies of light-matter coupling in deeply sub-wavelength volumes at THz frequencies.

Tunable resonant and non-resonant interactions between a phase qubit and LC resonator

NASA Astrophysics Data System (ADS)

Allman, Michael Shane; Whittaker, Jed D.; Castellanos-Beltran, Manuel; Cicak, Katarina; da Silva, Fabio; Defeo, Michael; Lecocq, Florent; Sirois, Adam; Teufel, John; Aumentado, Jose; Simmonds, Raymond W.

2014-03-01

We use a flux-biased radio frequency superconducting quantum interference device (rf SQUID) with an embedded flux-biased direct current (dc) SQUID to generate strong resonant and non-resonant tunable interactions between a phase qubit and a lumped-element resonator. The rf-SQUID creates a tunable magnetic susceptibility between the qubit and resonator providing resonant coupling rates from zero to near the ultra-strong coupling regime. By modulating the magnetic susceptibility, non-resonant parametric coupling achieves rates > 100 MHz . Nonlinearity of the magnetic susceptibility also leads to parametric coupling at subharmonics of the qubit-resonator detuning. Controllable coupling is generically important for constructing coupled-mode systems ubiquitous in physics, useful for both, quantum information architectures and quantum simulators. This work supported by NIST and NSA grant EAO140639.

Tunable photonic cavity coupled to a voltage-biased double quantum dot system: Diagrammatic nonequilibrium Green's function approach

NASA Astrophysics Data System (ADS)

Agarwalla, Bijay Kumar; Kulkarni, Manas; Mukamel, Shaul; Segal, Dvira

2016-07-01

We investigate gain in microwave photonic cavities coupled to voltage-biased double quantum dot systems with an arbitrarily strong dot-lead coupling and with a Holstein-like light-matter interaction, by employing the diagrammatic Keldysh nonequilibrium Green's function approach. We compute out-of-equilibrium properties of the cavity: its transmission, phase response, mean photon number, power spectrum, and spectral function. We show that by the careful engineering of these hybrid light-matter systems, one can achieve a significant amplification of the optical signal with the voltage-biased electronic system serving as a gain medium. We also study the steady-state current across the device, identifying elastic and inelastic tunneling processes which involve the cavity mode. Our results show how recent advances in quantum electronics can be exploited to build hybrid light-matter systems that behave as microwave amplifiers and photon source devices. The diagrammatic Keldysh approach is primarily discussed for a cavity-coupled double quantum dot architecture, but it is generalizable to other hybrid light-matter systems.

Dynamics of entanglement and the Schmidt gap in a driven light-matter system

NASA Astrophysics Data System (ADS)

Gómez-Ruiz, F. J.; Mendoza-Arenas, J. J.; Acevedo, O. L.; Rodríguez, F. J.; Quiroga, L.; Johnson, N. F.

2018-01-01

The ability to modify light-matter coupling in time (e.g. using external pulses) opens up the exciting possibility of generating and probing new aspects of quantum correlations in many-body light-matter systems. Here we study the impact of such a pulsed coupling on the light-matter entanglement in the Dicke model as well as the respective subsystem quantum dynamics. Our dynamical many-body analysis exploits the natural partition between the radiation and matter degrees of freedom, allowing us to explore time-dependent intra-subsystem quantum correlations by means of squeezing parameters, and the inter-subsystem Schmidt gap for different pulse duration (i.e. ramping velocity) regimes—from the near adiabatic to the sudden quench limits. Our results reveal that both types of quantities indicate the emergence of the superradiant phase when crossing the quantum critical point. In addition, at the end of the pulse light and matter remain entangled even though they become uncoupled, which could be exploited to generate entangled states in non-interacting systems.

Detection of internal fields in double-metal terahertz resonators

DOE PAGES

Mitrofanov, Oleg; Han, Zhanghua; Ding, Fei; ...

2017-02-06

(THz) plasmonic double-metal resonators enable enhanced light-matter coupling by utilizing strong localization of the resonant field. The closed resonator design however restricts investigations of the light-matter interaction effects. We propose and demonstrate a method for spatial mapping and spectroscopic analysis of the internal resonant THz fields in plasmonic double-metal THz resonators. We use the aperture-type scanning near-field THz time-domain microscopy and the concept of image charges to probe the THz fields confined within the resonator. The experimental method opens doors to studies of light-matter coupling in deeply sub-wavelength volumes at THz frequencies.

Room temperature strong light-matter coupling in three dimensional terahertz meta-atoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paulillo, B., E-mail: bruno.paulillo@u-psud.fr; Manceau, J.-M., E-mail: jean-michel.manceau@u-psud.fr; Colombelli, R., E-mail: raffaele.colombelli@u-psud.fr

2016-03-07

We demonstrate strong light-matter coupling in three dimensional terahertz meta-atoms at room temperature. The intersubband transition of semiconductor quantum wells with a parabolic energy potential is strongly coupled to the confined circuital mode of three-dimensional split-ring metal-semiconductor-metal resonators that have an extreme sub-wavelength volume (λ/10). The frequency of these lumped-element resonators is controlled by the size and shape of the external antenna, while the interaction volume remains constant. This allows the resonance frequency to be swept across the intersubband transition and the anti-crossing characteristic of the strong light-matter coupling regime to be observed. The Rabi splitting, which is twice themore » Rabi frequency (2Ω{sub Rabi}), amounts to 20% of the bare transition at room temperature, and it increases to 28% at low-temperature.« less

Novel High Cooperativity Photon-Magnon Cavity QED

NASA Astrophysics Data System (ADS)

Tobar, Michael; Bourhill, Jeremy; Kostylev, Nikita; G, Maxim; Creedon, Daniel

Novel microwave cavities are presented, which couple photons and magnons in YIG spheres in a super- and ultra-strong way at around 20 mK in temperature. Few/Single photon couplings (or normal mode splitting, 2g) of more than 6 GHz at microwave frequencies are obtained. Types of cavities include multiple post reentrant cavities, which co-couple photons at different frequencies with a coupling greater that the free spectral range, as well as spherical loaded dielectric cavity resonators. In such cavities we show that the bare dielectric properties can be obtained by polarizing all magnon modes to high energy using a 7 Tesla magnet. We also show that at zero-field, collective effects of the spins significantly perturb the photon modes. Other effects like time-reversal symmetry breaking are observed.

Can the exciton--polariton be defined by its quantum properties?

NASA Astrophysics Data System (ADS)

Fonseca-Romero, Karen; Cipagauta, Gustavo; Suárez-Forero, Daniel; Vinck-Posada, Herbert; Rey-González, Rafael; Herrera, William; Rodriguez, Boris

2013-03-01

We discuss the defining properties of a polariton in the framework of a microcavity-quantum dot system, described by a simple fully quantum model which takes into account loses and pumping. We show that even in the strong coupling regime, and provided that the emitted light exhibit subpoissonian statistics, the density operator of the system can be so mixed that quantum matter-radiation correlations are absent. We suggest the inclusion of matter-radiation entanglement as a defining property of the polariton. The weak-coupling, strong-coupling and lasing regimes, usually identified through the photoluminescence of the emitted light, can be understood in terms of quantum properties of the system state (entanglement, mixedness and light correlation functions). Our numerical anaylisis reveals the fundamental role of detuning on the coherence properties of the emitted light and on entanglement. In this sense, there is no polariton near resonance, even in the strong coupling regime. We show that the ``best'' polariton (maximally entangled matter-light state) is found when the exciton pumping rate is equal to the photon decay rate, and the detuning is of the order of three times the value of the coupling constant. The authors acknowledge partial financial support from Dirección de Investigación - Sede Bogotá, Universidad Nacional de Colombia (DIB-UNAL) under project 12584.

Ultrastrong extraordinary transmission and reflection in PT-symmetric Thue-Morse optical waveguide networks.

PubMed

Wu, Jiaye; Yang, Xiangbo

2017-10-30

In this paper, we construct a 1D PT-symmetric Thue-Morse aperiodic optical waveguide network (PTSTMAOWN) and mainly investigate the ultrastrong extraordinary transmission and reflection. We propose an approach to study the photonic modes and solve the problem of calculating photonic modes distributions in aperiodic networks due to the lack of dispersion functions and find that in a PTSTMAOWN there exist more photonic modes and more spontaneous PT-symmetric breaking points, which are quite different from other reported PT-symmetric optical systems. Additionally, we develop a method to sort spontaneous PT-symmetric breaking point zones to seek the strongest extraordinary point and obtain that at this point the strongest extraordinary transmission and reflection arrive at 2.96316 × 10 5 and 1.32761 × 10 5 , respectively, due to the PT-symmetric coupling resonance and the special symmetry pattern of TM networks. These enormous gains are several orders of magnitude larger than the previous results. This optical system may possess potential in designing optical amplifier, optical logic elements in photon computers and ultrasensitive optical switches with ultrahigh monochromatity.

Engineered circuit QED with dense resonant modes

NASA Astrophysics Data System (ADS)

Wilhelm, Frank; Egger, Daniel

2013-03-01

In circuit quantum electrodynamics even in the ultrastrong coupling regime, strong quasi-resonant interaction typically involves only one mode of the resonator as the mode spacing is comparable to the frequency of the mode. We are going to present an engineered hybrid transmission line consisting of a left-handed and a right-handed portion that has a low-frequency van-Hove singularity hence showing a dense mode spectrum at an experimentally accessible point. This gives rise to strong multi-mode coupling and can be utilized in multiple ways to create strongly correlated microwave photons. Supported by DARPA through the QuEST program and by NSERC Discovery grants

Second order nonlinear QED processes in ultra-strong laser fields

NASA Astrophysics Data System (ADS)

Mackenroth, Felix

2017-10-01

In the interaction of ultra-intense laser fields with matter the ever increasing peak laser intensities render nonlinear QED effects ever more important. For long, ultra-intense laser pulses scattering large systems, like a macroscopic plasma, the interaction time can be longer than the scattering time, leading to multiple scatterings. These are usually approximated as incoherent cascades of single-vertex processes. Under certain conditions, however, this common cascade approximation may be insufficient, as it disregards several effects such as coherent processes, quantum interferences or pulse shape effects. Quantifying deviations of the full amplitude of multiple scatterings from the commonly employed cascade approximations is a formidable, yet unaccomplished task. In this talk we are going to discuss how to compute second order nonlinear QED amplitudes and relate them to the conventional cascade approximation. We present examples for typical second order processes and benchmark the full result against common approximations. We demonstrate that the approximation of multiple nonlinear QED scatterings as a cascade of single interactions has certain limitations and discuss these limits in light of upcoming experimental tests.

Exciton-Polariton Dynamics of a Monolayer Semiconductor Coupled to a Microcavity

NASA Astrophysics Data System (ADS)

Chen, Yen-Jung; Stanev, Teodor K.; Stern, Nathaniel P.; Cain, Jeffrey D.; Dravid, Vinayak P.

Strong light-matter interactions, evidenced by exciton-polariton states, have been observed in the two-dimensional limit with monolayer transition metal dichalcogenides (TMDs) embedded in a microcavity. Because of the valley degree of freedom in monolayer TMDs, these hybrid light-matter states can exhibit valley polarization as in a bare monolayer, with strongly-coupled dynamics determined by the relative rates of exciton relaxation and intervalley scattering, which can be highly modified in on-resonant cavities. Here, we test this intuitive picture of the polarized exciton-polariton dynamics with monolayer MoS2 coupled to detuned cavities. Upper and lower polariton branches exhibit distinct decay rates indicative of different cavity dynamics. As with on-resonant, strongly-coupled exciton-polaritons, the weakly-coupled regime causes exciton-polariton valley polarization to persist at room temperature, demonstrating that dynamics of valley-polarized excitations can be controlled by engineering light-matter interactions. This work is supported by the U.S. Department of Energy (BES DE-SC0012130) and the National Science Foundation MRSEC program (DMR-1121262). N.P.S. is an Alfred P. Sloan Research Fellow.

An analytical variational method for the biased quantum Rabi model in the ultra-strong coupling regime

NASA Astrophysics Data System (ADS)

Mao, Bin-Bin; Liu, Maoxin; Wu, Wei; Li, Liangsheng; Ying, Zu-Jian; Luo, Hong-Gang

2018-05-01

Not Available Project supported by the National Natural Science Foundation of China (Grant Nos. 11674139, 11604009, and 11704025), the Program for Changjiang Scholars and Innovative Research Team in University, China (Grant No. IRT-16R35), and the Fundamental Research Funds for the Central Universities, China. ZJY also acknowledges the financial support of the Future and Emerging Technologies (FET) programme within the Seventh Framework Programme for Research of the European Commission, under FET-Open Grant No. 618083 (CNTQC).

Nonlinear quantum Rabi model in trapped ions

NASA Astrophysics Data System (ADS)

Cheng, Xiao-Hang; Arrazola, Iñigo; Pedernales, Julen S.; Lamata, Lucas; Chen, Xi; Solano, Enrique

2018-02-01

We study the nonlinear dynamics of trapped-ion models far away from the Lamb-Dicke regime. This nonlinearity induces a blockade on the propagation of quantum information along the Hilbert space of the Jaynes-Cummings and quantum Rabi models. We propose to use this blockade as a resource for the dissipative generation of high-number Fock states. Also, we compare the linear and nonlinear cases of the quantum Rabi model in the ultrastrong and deep strong-coupling regimes. Moreover, we propose a scheme to simulate the nonlinear quantum Rabi model in all coupling regimes. This can be done via off-resonant nonlinear red- and blue-sideband interactions in a single trapped ion, yielding applications as a dynamical quantum filter.

Thermal Dark Matter Below a MeV

DOE PAGES

Berlin, Asher; Blinov, Nikita

2018-01-08

We consider a class of models in which thermal dark matter is lighter than a MeV. If dark matter thermalizes with the standard model below the temperature of neutrino-photon decoupling, equilibration and freeze-out cool and heat the standard model bath comparably, alleviating constraints from measurements of the effective number of neutrino species. We demonstrate this mechanism in a model consisting of fermionic dark matter coupled to a light scalar mediator. Thermal dark matter can be as light as a few keV, while remaining compatible with existing cosmological and astrophysical observations. This framework motivates new experiments in the direct search formore » sub-MeV thermal dark matter and light force carriers.« less

Thermal Dark Matter Below a MeV

NASA Astrophysics Data System (ADS)

Berlin, Asher; Blinov, Nikita

2018-01-01

We consider a class of models in which thermal dark matter is lighter than a MeV. If dark matter thermalizes with the standard model below the temperature of neutrino-photon decoupling, equilibration and freeze-out cool and heat the standard model bath comparably, alleviating constraints from measurements of the effective number of neutrino species. We demonstrate this mechanism in a model consisting of fermionic dark matter coupled to a light scalar mediator. Thermal dark matter can be as light as a few keV, while remaining compatible with existing cosmological and astrophysical observations. This framework motivates new experiments in the direct search for sub-MeV thermal dark matter and light force carriers.

Thermal Dark Matter Below a MeV.

PubMed

Berlin, Asher; Blinov, Nikita

2018-01-12

We consider a class of models in which thermal dark matter is lighter than a MeV. If dark matter thermalizes with the standard model below the temperature of neutrino-photon decoupling, equilibration and freeze-out cool and heat the standard model bath comparably, alleviating constraints from measurements of the effective number of neutrino species. We demonstrate this mechanism in a model consisting of fermionic dark matter coupled to a light scalar mediator. Thermal dark matter can be as light as a few keV, while remaining compatible with existing cosmological and astrophysical observations. This framework motivates new experiments in the direct search for sub-MeV thermal dark matter and light force carriers.

Thermal Dark Matter Below a MeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berlin, Asher; Blinov, Nikita

We consider a class of models in which thermal dark matter is lighter than a MeV. If dark matter thermalizes with the standard model below the temperature of neutrino-photon decoupling, equilibration and freeze-out cool and heat the standard model bath comparably, alleviating constraints from measurements of the effective number of neutrino species. We demonstrate this mechanism in a model consisting of fermionic dark matter coupled to a light scalar mediator. Thermal dark matter can be as light as a few keV, while remaining compatible with existing cosmological and astrophysical observations. This framework motivates new experiments in the direct search formore » sub-MeV thermal dark matter and light force carriers.« less

Direct detection of light ''Ge-phobic'' exothermic dark matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gelmini, Graciela B.; Georgescu, Andreea; Huh, Ji-Haeng, E-mail: gelmini@physics.ucla.edu, E-mail: a.georgescu@physics.ucla.edu, E-mail: jhhuh@physics.ucla.edu

2014-07-01

We present comparisons of direct dark matter (DM) detection data for light WIMPs with exothermic scattering with nuclei (exoDM), both assuming the Standard Halo Model (SHM) and in a halo model–independent manner. Exothermic interactions favor light targets, thus reducing the importance of upper limits derived from xenon targets, the most restrictive of which is at present the LUX limit. In our SHM analysis the CDMS-II-Si and CoGeNT regions become allowed by these bounds, however the recent SuperCDMS limit rejects both regions for exoDM with isospin-conserving couplings. An isospin-violating coupling of the exoDM, in particular one with a neutron to protonmore » coupling ratio of -0.8 (which we call ''Ge-phobic''), maximally reduces the DM coupling to germanium and allows the CDMS-II-Si region to become compatible with all bounds. This is also clearly shown in our halo-independent analysis.« less

Single-molecule strong coupling at room temperature in plasmonic nanocavities

NASA Astrophysics Data System (ADS)

Chikkaraddy, Rohit; de Nijs, Bart; Benz, Felix; Barrow, Steven J.; Scherman, Oren A.; Rosta, Edina; Demetriadou, Angela; Fox, Peter; Hess, Ortwin; Baumberg, Jeremy J.

2016-07-01

Photon emitters placed in an optical cavity experience an environment that changes how they are coupled to the surrounding light field. In the weak-coupling regime, the extraction of light from the emitter is enhanced. But more profound effects emerge when single-emitter strong coupling occurs: mixed states are produced that are part light, part matter, forming building blocks for quantum information systems and for ultralow-power switches and lasers. Such cavity quantum electrodynamics has until now been the preserve of low temperatures and complicated fabrication methods, compromising its use. Here, by scaling the cavity volume to less than 40 cubic nanometres and using host-guest chemistry to align one to ten protectively isolated methylene-blue molecules, we reach the strong-coupling regime at room temperature and in ambient conditions. Dispersion curves from more than 50 such plasmonic nanocavities display characteristic light-matter mixing, with Rabi frequencies of 300 millielectronvolts for ten methylene-blue molecules, decreasing to 90 millielectronvolts for single molecules—matching quantitative models. Statistical analysis of vibrational spectroscopy time series and dark-field scattering spectra provides evidence of single-molecule strong coupling. This dressing of molecules with light can modify photochemistry, opening up the exploration of complex natural processes such as photosynthesis and the possibility of manipulating chemical bonds.

Coherent strong field interactions between a nanomagnet and a photonic cavity

NASA Astrophysics Data System (ADS)

Soykal, Oney Orhunc

Strong coupling of light and matter is an essential element of cavity quantum electrodynamics (cavity-QED) and quantum optics, which may lead to novel mixed states of light and matter and to applications such as quantum computation. In the strong-coupling regime, where the coupling strength exceeds the dissipation, the light-matter interaction produces a characteristic vacuum Rabi splitting. Therefore, strong coupling can be utilized as an effective coherent interface between light and matter (in the form of electron charge, spin or superconducting Cooper pairs) to achieve components of quantum information technology including quantum memory, teleportation, and quantum repeaters. Semiconductor quantum dots, nuclear spins and paramagnetic spin systems are only some of the material systems under investigation for strong coupling in solid-state physics. Mixed states of light and matter coupled via electric dipole transitions often suffer from short coherence times (nanoseconds). Even though magnetic transitions appear to be intrinsically more quantum coherent than orbital transitions, their typical coupling strengths have been estimated to be much smaller. Hence, they have been neglected for the purposes of quantum information technology. However, we predict that strong coupling is feasible between photons and a ferromagnetic nanomagnet, due to exchange interactions that cause very large numbers of spins to coherently lock together with a significant increase in oscillator strength while still maintaining very long coherence times. In order to examine this new exciting possibility, the interaction of a ferromagnetic nanomagnet with a single photonic mode of a cavity is analyzed in a fully quantum-mechanical treatment. Exceptionally large quantum-coherent magnet-photon coupling with coupling terms in excess of several THz are predicted to be achievable in a spherical cavity of ˜ 1 mm radius with a nanomagnet of ˜ 100 nm radius and ferromagnet resonance frequency of ˜ 200 GHz. This should substantially exceed the coupling observed in solids between orbital transitions and light. Eigenstates of the nanomagnet-photon system correspond to entangled states of spin orientation and photon number over 105 values of each quantum number. Initial coherent state of definite spin and photon number evolve dynamically to produce large coherent oscillations in the microwave power with exceptionally long dephasing times of few seconds. In addition to dephasing, several decoherence mechanisms including elementary excitation of magnons and crystalline magnetic anisotropy are investigated and shown to not substantially affect coherence upto room temperature. For small nanomagnets the crystalline magnetic anisotropy of the magnet strongly localize the eigenstates in photon and spin number, quenching the potential for coherent states and for a sufficiently large nanomagnet the macrospin approximation breaks down and different domains of the nanomagnet may couple separately to the photonic mode. Thus the optimal nanomagnet size is predicted to be just below the threshold for failure of the macrospin approximation. Moreover, it is shown that initially unentangled coherent states of light (cavity field) and spin (nanomagnet spin orientation) can be phase-locked to evolve into a coherent entangled states of the system under the influence of strong coupling.

Exciton-plasmon coupling interactions: from principle to applications

NASA Astrophysics Data System (ADS)

Cao, En; Lin, Weihua; Sun, Mengtao; Liang, Wenjie; Song, Yuzhi

2018-01-01

The interaction of exciton-plasmon coupling and the conversion of exciton-plasmon-photon have been widely investigated experimentally and theoretically. In this review, we introduce the exciton-plasmon interaction from basic principle to applications. There are two kinds of exciton-plasmon coupling, which demonstrate different optical properties. The strong exciton-plasmon coupling results in two new mixed states of light and matter separated energetically by a Rabi splitting that exhibits a characteristic anticrossing behavior of the exciton-LSP energy tuning. Compared to strong coupling, such as surface-enhanced Raman scattering, surface plasmon (SP)-enhanced absorption, enhanced fluorescence, or fluorescence quenching, there is no perturbation between wave functions; the interaction here is called the weak coupling. SP resonance (SPR) arises from the collective oscillation induced by the electromagnetic field of light and can be used for investigating the interaction between light and matter beyond the diffraction limit. The study on the interaction between SPR and exaction has drawn wide attention since its discovery not only due to its contribution in deepening and broadening the understanding of SPR but also its contribution to its application in light-emitting diodes, solar cells, low threshold laser, biomedical detection, quantum information processing, and so on.

Generalized squeezing rotating-wave approximation to the isotropic and anisotropic Rabi model in the ultrastrong-coupling regime

NASA Astrophysics Data System (ADS)

Zhang, Yu-Yu

2016-12-01

Generalized squeezing rotating-wave approximation (GSRWA) is proposed by employing both the displacement and the squeezing transformations. A solvable Hamiltonian is reformulated in the same form as the ordinary RWA ones. For a qubit coupled to oscillators experiment, a well-defined Schrödinger-cat-like entangled state is given by the displaced-squeezed oscillator state instead of the original displaced state. For the isotropic Rabi case, the mean photon number and the ground-state energy are expressed analytically with additional squeezing terms, exhibiting a substantial improvement of the GSRWA. And the ground-state energy in the anisotropic Rabi model confirms the effectiveness of the GSRWA. Due to the squeezing effect, the GSRWA improves the previous methods only with the displacement transformation in a wide range of coupling strengths even for large atom frequency.

Displacemon Electromechanics: How to Detect Quantum Interference in a Nanomechanical Resonator

NASA Astrophysics Data System (ADS)

Khosla, K. E.; Vanner, M. R.; Ares, N.; Laird, E. A.

2018-04-01

We introduce the "displacemon" electromechanical architecture that comprises a vibrating nanobeam, e.g., a carbon nanotube, flux coupled to a superconducting qubit. This platform can achieve strong and even ultrastrong coupling, enabling a variety of quantum protocols. We use this system to describe a protocol for generating and measuring quantum interference between trajectories of a nanomechanical resonator. The scheme uses a sequence of qubit manipulations and measurements to cool the resonator, to apply two effective diffraction gratings, and then to measure the resulting interference pattern. We demonstrate the feasibility of generating a spatially distinct quantum superposition state of motion containing more than 1 06 nucleons using a vibrating nanotube acting as a junction in this new superconducting qubit configuration.

Constraints on the {omega}- and {sigma}-meson coupling constants with dibaryons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faessler, A.; Buchmann, A.J.; Krivoruchenko, M.I.

The effect of narrow dibaryon resonances on basic nuclear matter properties and on the structure of neutron stars is investigated in mean-field theory and in relativistic Hartree approximation. The existence of massive neutron stars imposes constraints on the coupling constants of the {omega} and {sigma} mesons with dibaryons. In the allowed region of the parameter space of the coupling constants, a Bose condensate of the light dibaryon candidates d{sub 1}(1920) and d{sup {prime}}(2060) is stable against compression. This proves the stability of the ground state of heterophase nuclear matter with a Bose condensate of light dibaryons. {copyright} {ital 1997} {italmore » The American Physical Society}« less

Electromagnetic waves propagating in the string axiverse

NASA Astrophysics Data System (ADS)

Yoshida, Daiske; Soda, Jiro

2018-04-01

It is widely believed that axions are ubiquitous in string theory and could be dark matter. The peculiar features of axion dark matter are coherent oscillations and a coupling to the electromagnetic field through the Chern-Simons term. In this letter, we study the consequences of these two features of axions with mass in the range 10^{-13} eV to 103 eV. First, we study the parametric resonance of electromagnetic waves induced by the coherent oscillation of the axion. Since the resonance frequency is determined by the mass of the axion dark matter, if we detect this signal, we can get information on the mass of the axion dark matter. Second, we study the velocity of light in the background of the axion dark matter. In the presence of the Chern-Simons term, the dispersion relation is modified and the speed of light will oscillate in time. It turns out that the change in the speed of light would be difficult to observe. We argue that future radio wave observations of the resonance can give rise to a stronger constraint on the coupling constant and/or the density of the axion dark matter.

Neutrino Oscillations as a Probe of Light Scalar Dark Matter.

PubMed

Berlin, Asher

2016-12-02

We consider a class of models involving interactions between ultralight scalar dark matter and standard model neutrinos. Such couplings modify the neutrino mass splittings and mixing angles to include additional components that vary in time periodically with a frequency and amplitude set by the mass and energy density of the dark matter. Null results from recent searches for anomalous periodicities in the solar neutrino flux strongly constrain the dark matter-neutrino coupling to be orders of magnitude below current and projected limits derived from observations of the cosmic microwave background.

Passive and active mid-infrared semiconductor nanostructures: Three-dimensional metamaterials and high wall plug efficiency quantum cascade lasers

NASA Astrophysics Data System (ADS)

Hoffman, Anthony J.

Every instant, light and matter are interacting in ways that shape the world around us. This dissertation examines the interaction of mid-infrared light with stacks of thin semiconductor layers. The work is divided into two parts: mid-infrared metamaterials and high wall plug efficiency (WPE) Quantum Cascade (QC) lasers. The mid-infrared metamaterials represent an entirely new class of material and have great potential for enabling highly-desired applications such as sub-diffraction imaging, confinement, and waveguiding. High WPE QC lasers greatly enhance the commercial feasibility of sensing, infrared countermeasures and free-space infrared communications. The first part of this dissertation describes the first three-dimensional, optical metamaterial. The all-semiconductor metamaterial is based on a strongly anisotropic dielectric function and exhibits negative refraction for a large bandwidth in the mid-infrared. The underlying theory of strongly anisotropic metamaterials is discussed, detailed characterization of several metamaterials is presented, and a macroscopic beam experiment is employed to demonstrate negative refraction. A detailed study of waveguides with strongly anisotropic cores is also presented and the low-order mode cutoff for such left-handed waveguides is observed. The second part of this dissertation discusses improvements in QC laser WPE through improved processing, packaging, and design. Devices using conventional QC design strategies processed as buried heterostructures operate with 5% WPE at room temperature in continuous wave mode, a significant improvement over previous generation devices. To further improve WPE, QC lasers based on ultra-strong coupling between the injector and upper-laser levels are designed and characterized. These devices operate with nearly 50% pulsed WPE---a true milestone for QC technology. A new type of QC laser design incorporating heterogeneous injector regions to reduce the voltage defect and thus improve WPE is also presented. Optimized devices exhibit efficiencies in excess of 30% at cryogenic temperatures. Finally, a new measurement technique to characterize lasers in continuous wave operation is described in detail. The technique is used to measure the instantaneous threshold, active core heating, device thermal resistance, and laser current efficiency as well as determine the cause of light power roll-over. This new characterization technique allows for improved understanding of QC lasers and further improvements in device performance.

Direct detection of light “Ge-phobic” exothermic dark matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gelmini, Graciela B.; Georgescu, Andreea; Huh, Ji-Haeng

2014-07-15

We present comparisons of direct dark matter (DM) detection data for light WIMPs with exothermic scattering with nuclei (exoDM), both assuming the Standard Halo Model (SHM) and in a halo model — independent manner. Exothermic interactions favor light targets, thus reducing the importance of upper limits derived from xenon targets, the most restrictive of which is at present the LUX limit. In our SHM analysis the CDMS-II-Si and CoGeNT regions become allowed by these bounds, however the recent SuperCDMS limit rejects both regions for exoDM with isospin-conserving couplings. An isospin-violating coupling of the exoDM, in particular one with a neutronmore » to proton coupling ratio of −0.8 (which we call “Ge-phobic”), maximally reduces the DM coupling to germanium and allows the CDMS-II-Si region to become compatible with all bounds. This is also clearly shown in our halo-independent analysis.« less

Plasma physics of extreme astrophysical environments.

PubMed

Uzdensky, Dmitri A; Rightley, Shane

2014-03-01

Among the incredibly diverse variety of astrophysical objects, there are some that are characterized by very extreme physical conditions not encountered anywhere else in the Universe. Of special interest are ultra-magnetized systems that possess magnetic fields exceeding the critical quantum field of about 44 TG. There are basically only two classes of such objects: magnetars, whose magnetic activity is manifested, e.g., via their very short but intense gamma-ray flares, and central engines of supernovae (SNe) and gamma-ray bursts (GRBs)--the most powerful explosions in the modern Universe. Figuring out how these complex systems work necessarily requires understanding various plasma processes, both small-scale kinetic and large-scale magnetohydrodynamic (MHD), that govern their behavior. However, the presence of an ultra-strong magnetic field modifies the underlying basic physics to such a great extent that relying on conventional, classical plasma physics is often not justified. Instead, plasma-physical problems relevant to these extreme astrophysical environments call for constructing relativistic quantum plasma (RQP) physics based on quantum electrodynamics (QED). In this review, after briefly describing the astrophysical systems of interest and identifying some of the key plasma-physical problems important to them, we survey the recent progress in the development of such a theory. We first discuss the ways in which the presence of a super-critical field modifies the properties of vacuum and matter and then outline the basic theoretical framework for describing both non-relativistic and RQPs. We then turn to some specific astrophysical applications of relativistic QED plasma physics relevant to magnetar magnetospheres and to central engines of core-collapse SNe and long GRBs. Specifically, we discuss the propagation of light through a magnetar magnetosphere; large-scale MHD processes driving magnetar activity and responsible for jet launching and propagation in GRBs; energy-transport processes governing the thermodynamics of extreme plasma environments; micro-scale kinetic plasma processes important in the interaction of intense electric currents flowing through a magnetar magnetosphere with the neutron star surface; and magnetic reconnection of ultra-strong magnetic fields. Finally, we point out that future progress in applying RQP physics to real astrophysical problems will require the development of suitable numerical modeling capabilities.

Cavity quantum electrodynamics in the nonperturbative regime

NASA Astrophysics Data System (ADS)

De Bernardis, Daniele; Jaako, Tuomas; Rabl, Peter

2018-04-01

We study a generic cavity-QED system where a set of (artificial) two-level dipoles is coupled to the electric field of a single-mode L C resonator. This setup is used to derive a minimal quantum mechanical model for cavity QED, which accounts for both dipole-field and direct dipole-dipole interactions. The model is applicable for arbitrary coupling strengths and allows us to extend the usual Dicke model into the nonperturbative regime of QED, where the dipole-field interaction can be associated with an effective fine-structure constant of order unity. In this regime, we identify three distinct classes of normal, superradiant, and subradiant vacuum states and discuss their characteristic properties and the transitions between them. Our findings reconcile many of the previous, often contradictory predictions in this field and establish a common theoretical framework to describe ultrastrong-coupling phenomena in a diverse range of cavity-QED platforms.

Dynamics of superconducting qubits in open transmission lines

NASA Astrophysics Data System (ADS)

Juan Jose, Garcia-Ripoll; Zueco, David; Porras, Diego; Peropadre, Borja

2014-03-01

The time and space resolved dynamics of a superconducting qubit with an Ohmic coupling to propagating 1D photons is studied, from weak coupling to the ultrastrong coupling regime (USC). A nonperturbative study based on Matrix Product States (MPS) shows the following results: (i) The ground state of the combined systems contains excitations of both the qubit and the surrounding bosonic field. (ii) An initially excited qubit equilibrates through spontaneous emission to a state, which under certain conditions, is locally close to that ground state, both in the qubit and the field. (iii) The resonances of the combined qubit-photon system match those of the spontaneous emission process and also the predictions of the adiabatic renormalisation. These results set the foundations for future studies and engineering of the interactions between superconducting qubits and propagating photons, as well as the design of photon-photon interactions based on artificial materials built from these qubits.

Nonlinear Dynamics and Strong Cavity Cooling of Levitated Nanoparticles.

PubMed

Fonseca, P Z G; Aranas, E B; Millen, J; Monteiro, T S; Barker, P F

2016-10-21

Optomechanical systems explore and exploit the coupling between light and the mechanical motion of macroscopic matter. A nonlinear coupling offers rich new physics, in both quantum and classical regimes. We investigate a dynamic, as opposed to the usually studied static, nonlinear optomechanical system, comprising a nanosphere levitated in a hybrid electro-optical trap. The cavity offers readout of both linear-in-position and quadratic-in-position (nonlinear) light-matter coupling, while simultaneously cooling the nanosphere, for indefinite periods of time and in high vacuum. We observe the cooling dynamics via both linear and nonlinear coupling. As the background gas pressure was lowered, we observed a greater than 1000-fold reduction in temperature before temperatures fell below readout sensitivity in the present setup. This Letter opens the way to strongly coupled quantum dynamics between a cavity and a nanoparticle largely decoupled from its environment.

Nonlinear Dynamics and Strong Cavity Cooling of Levitated Nanoparticles

NASA Astrophysics Data System (ADS)

Fonseca, P. Z. G.; Aranas, E. B.; Millen, J.; Monteiro, T. S.; Barker, P. F.

2016-10-01

Optomechanical systems explore and exploit the coupling between light and the mechanical motion of macroscopic matter. A nonlinear coupling offers rich new physics, in both quantum and classical regimes. We investigate a dynamic, as opposed to the usually studied static, nonlinear optomechanical system, comprising a nanosphere levitated in a hybrid electro-optical trap. The cavity offers readout of both linear-in-position and quadratic-in-position (nonlinear) light-matter coupling, while simultaneously cooling the nanosphere, for indefinite periods of time and in high vacuum. We observe the cooling dynamics via both linear and nonlinear coupling. As the background gas pressure was lowered, we observed a greater than 1000-fold reduction in temperature before temperatures fell below readout sensitivity in the present setup. This Letter opens the way to strongly coupled quantum dynamics between a cavity and a nanoparticle largely decoupled from its environment.

Study of dark matter and QCD-charged mediators in the quasidegenerate regime

NASA Astrophysics Data System (ADS)

Davidson, Andrew; Kelso, Chris; Kumar, Jason; Sandick, Pearl; Stengel, Patrick

2017-12-01

We study a scenario in which the only light new particles are a Majorana fermion dark matter candidate and one or more QCD-charged scalars, which couple to light quarks. This scenario has several interesting phenomenological features if the new particles are nearly degenerate in mass. In particular, LHC searches for the light scalars have reduced sensitivity, since the visible and invisible products tend to be softer. Moreover, dark matter-scalar coannihilation can allow even relatively heavy dark matter candidates to be consistent thermal relics. Finally, the dark matter nucleon scattering cross section is enhanced in the quasidegenerate limit, allowing direct detection experiments to use both spin-independent and spin-dependent scattering to probe regions of parameter space beyond those probed by the LHC. Although this scenario has a broad application, we phrase this study in terms of the minimal supersymmetric standard model, in the limit where the only light sparticles are a binolike dark matter candidate and light-flavored squarks.

MICROSCOPE Mission: First Constraints on the Violation of the Weak Equivalence Principle by a Light Scalar Dilaton

NASA Astrophysics Data System (ADS)

Bergé, Joel; Brax, Philippe; Métris, Gilles; Pernot-Borràs, Martin; Touboul, Pierre; Uzan, Jean-Philippe

2018-04-01

The existence of a light or massive scalar field with a coupling to matter weaker than gravitational strength is a possible source of violation of the weak equivalence principle. We use the first results on the Eötvös parameter by the MICROSCOPE experiment to set new constraints on such scalar fields. For a massive scalar field of mass smaller than 10-12 eV (i.e., range larger than a few 1 05 m ), we improve existing constraints by one order of magnitude to |α |<10-11 if the scalar field couples to the baryon number and to |α |<10-12 if the scalar field couples to the difference between the baryon and the lepton numbers. We also consider a model describing the coupling of a generic dilaton to the standard matter fields with five parameters, for a light field: We find that, for masses smaller than 10-12 eV , the constraints on the dilaton coupling parameters are improved by one order of magnitude compared to previous equivalence principle tests.

MICROSCOPE Mission: First Constraints on the Violation of the Weak Equivalence Principle by a Light Scalar Dilaton.

PubMed

Bergé, Joel; Brax, Philippe; Métris, Gilles; Pernot-Borràs, Martin; Touboul, Pierre; Uzan, Jean-Philippe

2018-04-06

The existence of a light or massive scalar field with a coupling to matter weaker than gravitational strength is a possible source of violation of the weak equivalence principle. We use the first results on the Eötvös parameter by the MICROSCOPE experiment to set new constraints on such scalar fields. For a massive scalar field of mass smaller than 10^{-12}  eV (i.e., range larger than a few 10^{5}  m), we improve existing constraints by one order of magnitude to |α|<10^{-11} if the scalar field couples to the baryon number and to |α|<10^{-12} if the scalar field couples to the difference between the baryon and the lepton numbers. We also consider a model describing the coupling of a generic dilaton to the standard matter fields with five parameters, for a light field: We find that, for masses smaller than 10^{-12}  eV, the constraints on the dilaton coupling parameters are improved by one order of magnitude compared to previous equivalence principle tests.

Analytical Solution for the Anisotropic Rabi Model: Effects of Counter-Rotating Terms

NASA Astrophysics Data System (ADS)

Zhang, Guofeng; Zhu, Hanjie

2015-03-01

The anisotropic Rabi model, which was proposed recently, differs from the original Rabi model: the rotating and counter-rotating terms are governed by two different coupling constants. This feature allows us to vary the counter-rotating interaction independently and explore the effects of it on some quantum properties. In this paper, we eliminate the counter-rotating terms approximately and obtain the analytical energy spectrums and wavefunctions. These analytical results agree well with the numerical calculations in a wide range of the parameters including the ultrastrong coupling regime. In the weak counter-rotating coupling limit we find out that the counter-rotating terms can be considered as the shifts to the parameters of the Jaynes-Cummings model. This modification shows the validness of the rotating-wave approximation on the assumption of near-resonance and relatively weak coupling. Moreover, the analytical expressions of several physics quantities are also derived, and the results show the break-down of the U(1)-symmetry and the deviation from the Jaynes-Cummings model.

Analytical solution for the anisotropic Rabi model: effects of counter-rotating terms.

PubMed

Zhang, Guofeng; Zhu, Hanjie

2015-03-04

The anisotropic Rabi model, which was proposed recently, differs from the original Rabi model: the rotating and counter-rotating terms are governed by two different coupling constants. This feature allows us to vary the counter-rotating interaction independently and explore the effects of it on some quantum properties. In this paper, we eliminate the counter-rotating terms approximately and obtain the analytical energy spectrums and wavefunctions. These analytical results agree well with the numerical calculations in a wide range of the parameters including the ultrastrong coupling regime. In the weak counter-rotating coupling limit we find out that the counter-rotating terms can be considered as the shifts to the parameters of the Jaynes-Cummings model. This modification shows the validness of the rotating-wave approximation on the assumption of near-resonance and relatively weak coupling. Moreover, the analytical expressions of several physics quantities are also derived, and the results show the break-down of the U(1)-symmetry and the deviation from the Jaynes-Cummings model.

Analytical Solution for the Anisotropic Rabi Model: Effects of Counter-Rotating Terms

PubMed Central

Zhang, Guofeng; Zhu, Hanjie

2015-01-01

The anisotropic Rabi model, which was proposed recently, differs from the original Rabi model: the rotating and counter-rotating terms are governed by two different coupling constants. This feature allows us to vary the counter-rotating interaction independently and explore the effects of it on some quantum properties. In this paper, we eliminate the counter-rotating terms approximately and obtain the analytical energy spectrums and wavefunctions. These analytical results agree well with the numerical calculations in a wide range of the parameters including the ultrastrong coupling regime. In the weak counter-rotating coupling limit we find out that the counter-rotating terms can be considered as the shifts to the parameters of the Jaynes-Cummings model. This modification shows the validness of the rotating-wave approximation on the assumption of near-resonance and relatively weak coupling. Moreover, the analytical expressions of several physics quantities are also derived, and the results show the break-down of the U(1)-symmetry and the deviation from the Jaynes-Cummings model. PMID:25736827

Recent theoretical advances on superradiant phase transitions

NASA Astrophysics Data System (ADS)

Baksic, Alexandre; Nataf, Pierre; Ciuti, Cristiano

2013-03-01

The Dicke model describing a single-mode boson field coupled to two-level systems is an important paradigm in quantum optics. In particular, the physics of ``superradiant phase transitions'' in the ultrastrong coupling regime is the subject of a vigorous research activity in both cavity and circuit QED. Recently, we explored the rich physics of two interesting generalizations of the Dicke model: (i) A model describing the coupling of a boson mode to two independent chains A and B of two-level systems, where chain A is coupled to one quadrature of the boson field and chain B to the orthogonal quadrature. This original model leads to a quantum phase transition with a double symmetry breaking and a fourfold ground state degeneracy. (ii) A generalized Dicke model with three-level systems including the diamagnetic term. In contrast to the case of two-level atoms for which no-go theorems exist, in the case of three-level system we prove that the Thomas-Reich-Kuhn sum rule does not always prevent a superradiant phase transition.

Compressed glassy carbon: An ultrastrong and elastic interpenetrating graphene network

PubMed Central

Hu, Meng; He, Julong; Zhao, Zhisheng; Strobel, Timothy A.; Hu, Wentao; Yu, Dongli; Sun, Hao; Liu, Lingyu; Li, Zihe; Ma, Mengdong; Kono, Yoshio; Shu, Jinfu; Mao, Ho-kwang; Fei, Yingwei; Shen, Guoyin; Wang, Yanbin; Juhl, Stephen J.; Huang, Jian Yu; Liu, Zhongyuan; Xu, Bo; Tian, Yongjun

2017-01-01

Carbon’s unique ability to have both sp2 and sp3 bonding states gives rise to a range of physical attributes, including excellent mechanical and electrical properties. We show that a series of lightweight, ultrastrong, hard, elastic, and conductive carbons are recovered after compressing sp2-hybridized glassy carbon at various temperatures. Compression induces the local buckling of graphene sheets through sp3 nodes to form interpenetrating graphene networks with long-range disorder and short-range order on the nanometer scale. The compressed glassy carbons have extraordinary specific compressive strengths—more than two times that of commonly used ceramics—and simultaneously exhibit robust elastic recovery in response to local deformations. This type of carbon is an optimal ultralight, ultrastrong material for a wide range of multifunctional applications, and the synthesis methodology demonstrates potential to access entirely new metastable materials with exceptional properties. PMID:28630918

Role of quantum correlations in light-matter quantum heat engines

NASA Astrophysics Data System (ADS)

Barrios, G. Alvarado; Albarrán-Arriagada, F.; Cárdenas-López, F. A.; Romero, G.; Retamal, J. C.

2017-11-01

We study a quantum Otto engine embedding a working substance composed of a two-level system interacting with a harmonic mode. The physical properties of the substance are described by a generalized quantum Rabi model arising in superconducting circuit realizations. We show that light-matter quantum correlation reduction during the hot bath stage and adiabatic stages act as an indicator for enhanced work extraction and efficiency, respectively. Also, we demonstrate that the anharmonic spectrum of the working substance has a direct impact on the transition from heat engine into refrigerator as the light-matter coupling is increased. These results shed light on the search for optimal conditions in the performance of quantum heat engines.

Light-matter interaction in the strong coupling regime: configurations, conditions, and applications.

PubMed

Dovzhenko, D S; Ryabchuk, S V; Rakovich, Yu P; Nabiev, I R

2018-02-22

Resonance interaction between a molecular transition and a confined electromagnetic field can reach the coupling regime where coherent exchange of energy between light and matter becomes reversible. In this case, two new hybrid states separated in energy are formed instead of independent eigenstates, which is known as Rabi splitting. This modification of the energy spectra of the system offers new possibilities for controlled impact on various fundamental properties of coupled matter (such as the rate of chemical reactions and the conductivity of organic semiconductors). To date, the strong coupling regime has been demonstrated in many configurations under different ambient conditions. However, there is still no comprehensive approach to determining parameters for achieving the strong coupling regime for a wide range of practical applications. In this review, a detailed analysis of various systems and corresponding conditions for reaching strong coupling is carried out and their advantages and disadvantages, as well as the prospects for application, are considered. The review also summarizes recent experiments in which the strong coupling regime has led to new interesting results, such as the possibility of collective strong coupling between X-rays and matter excitation in a periodic array of Fe isotopes, which extends the applications of quantum optics; a strong amplification of the Raman scattering signal from a coupled system, which can be used in surface-enhanced and tip-enhanced Raman spectroscopy; and more efficient second-harmonic generation from the low polaritonic state, which is promising for nonlinear optics. The results reviewed demonstrate great potential for further practical applications of strong coupling in the fields of photonics (low-threshold lasers), quantum communications (switches), and biophysics (molecular fingerprinting).

A synthetic biological quantum optical system

DOE PAGES

Lishchuk, Anna; Kodali, Goutham; Mancini, Joshua A.; ...

2018-01-01

Strong coupling between plasmon modes and chlorins in synthetic light-harvesting maquette proteins yields hybrid light–matter states (plexcitons) whose energies are controlled by design of protein structure, enabling the creation of new states not seen under weak coupling.

A taste of dark matter: Flavour constraints on pseudoscalar mediators

DOE PAGES

Dolan, Matthew J.; Kahlhoefer, Felix; McCabe, Christopher; ...

2015-03-31

Dark matter interacting via the exchange of a light pseudoscalar can induce observable signals in indirect detection experiments and experience large self-interactions while evading the strong bounds from direct dark matter searches. The pseudoscalar mediator will however induce flavour-changing interactions in the Standard Model, providing a promising alternative way to test these models. We investigate in detail the constraints arising from rare meson decays and fixed target experiments for different coupling structures between the pseudoscalar and Standard Model fermions. The resulting bounds are highly complementary to the information inferred from the dark matter relic density and the constraints from primordialmore » nucleosynthesis. We discuss the implications of our findings for the dark matter self-interaction cross section and the prospects of probing dark matter coupled to a light pseudoscalar with direct or indirect detection experiments. In particular, we find that a pseudoscalar mediator can only explain the Galactic Centre excess if its mass is above that of the B mesons, and that it is impossible to obtain a sufficiently large direct detection cross section to account for the DAMA modulation.« less

3.55 keV line from exciting dark matter without a hidden sector

DOE PAGES

Berlin, Asher; DiFranzo, Anthony; Hooper, Dan

2015-04-24

In this study, models in which dark matter particles can scatter into a slightly heavier state which promptly decays to the lighter state and a photon (known as eXciting Dark Matter, or XDM) have been shown to be capable of generating the 3.55 keV line observed from galaxy clusters, while suppressing the flux of such a line from smaller halos, including dwarf galaxies. In most of the XDM models discussed in the literature, this up-scattering is mediated by a new light particle, and dark matter annihilations proceed into pairs of this same light state. In these models, the dark matter andmore » the mediator effectively reside within a hidden sector, without sizable couplings to the Standard Model. In this paper, we explore a model of XDM that does not include a hidden sector. Instead, the dark matter both up-scatters and annihilates through the near resonant exchange of an O(10 2) GeV pseudoscalar with large Yukawa couplings to the dark matter and smaller, but non-neglibile, couplings to Standard Model fermions. The dark matter and the mediator are each mixtures of Standard Model singlets and SU(2) W doublets. We identify parameter space in which this model can simultaneously generate the 3.55 keV line and the gamma-ray excess observed from the Galactic center, without conflicting with constraints from colliders, direct detection experiments, or observations of dwarf galaxies.« less

Epsilon-near-zero modes for tailored light-matter interaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Campione, Salvatore; Liu, Sheng; Benz, Alexander

Epsilon-near-zero (ENZ) modes arising from condensed-matter excitations such as phonons and plasmons are a new path for tailoring light-matter interactions at the nanoscale. Complex spectral shaping can be achieved by creating such modes in nanoscale semiconductor layers and controlling their interaction with multiple, distinct, dipole resonant systems. Examples of this behavior are presented at midinfrared frequencies for ENZ modes that are strongly coupled to metamaterial resonators and simultaneously strongly coupled to semiconductor phonons or quantum-well intersubband transitions (ISTs), resulting in double- and triple-polariton branches in transmission spectra. For the double-polariton branch case, we find that the best strategy to maximizemore » the Rabi splitting is to use a combination of a doped layer supporting an ENZ feature and a layer supporting ISTs, with overlapping ENZ and IST frequencies. As a result, this design flexibility renders this platform attractive for low-voltage tunable filters, light-emitting diodes, and efficient nonlinear composite materials.« less

Strong Light-Matter Interactions in Single Open Plasmonic Nanocavities at the Quantum Optics Limit.

PubMed

Liu, Renming; Zhou, Zhang-Kai; Yu, Yi-Cong; Zhang, Tengwei; Wang, Hao; Liu, Guanghui; Wei, Yuming; Chen, Huanjun; Wang, Xue-Hua

2017-06-09

Reaching the quantum optics limit of strong light-matter interactions between a single exciton and a plasmon mode is highly desirable, because it opens up possibilities to explore room-temperature quantum devices operating at the single-photon level. However, two challenges severely hinder the realization of this limit: the integration of single-exciton emitters with plasmonic nanostructures and making the coupling strength at the single-exciton level overcome the large damping of the plasmon mode. Here, we demonstrate that these two hindrances can be overcome by attaching individual J aggregates to single cuboid Au@Ag nanorods. In such hybrid nanosystems, both the ultrasmall mode volume of ∼71  nm^{3} and the ultrashort interaction distance of less than 0.9 nm make the coupling coefficient between a single J-aggregate exciton and the cuboid nanorod as high as ∼41.6  meV, enabling strong light-matter interactions to be achieved at the quantum optics limit in single open plasmonic nanocavities.

Epsilon-near-zero modes for tailored light-matter interaction

DOE PAGES

Campione, Salvatore; Liu, Sheng; Benz, Alexander; ...

2015-10-20

Epsilon-near-zero (ENZ) modes arising from condensed-matter excitations such as phonons and plasmons are a new path for tailoring light-matter interactions at the nanoscale. Complex spectral shaping can be achieved by creating such modes in nanoscale semiconductor layers and controlling their interaction with multiple, distinct, dipole resonant systems. Examples of this behavior are presented at midinfrared frequencies for ENZ modes that are strongly coupled to metamaterial resonators and simultaneously strongly coupled to semiconductor phonons or quantum-well intersubband transitions (ISTs), resulting in double- and triple-polariton branches in transmission spectra. For the double-polariton branch case, we find that the best strategy to maximizemore » the Rabi splitting is to use a combination of a doped layer supporting an ENZ feature and a layer supporting ISTs, with overlapping ENZ and IST frequencies. As a result, this design flexibility renders this platform attractive for low-voltage tunable filters, light-emitting diodes, and efficient nonlinear composite materials.« less

Strong-interaction-mediated critical coupling at two distinct frequencies.

PubMed

Gupta, S Dutta

2007-06-01

I study a multilayered medium consisting of a metal-dielectric composite film, a spacer layer, and a dielectric Bragg reflector. I demonstrate a greater flexibility over the critical coupling phenomenon [Tischler et al., Opt. Lett. 31, 2045 (2006)], whereby nearly all the incident light energy is absorbed by the composite film through suppression of both transmission and reflection from the structure. For a larger volume fraction of the metal inclusions, strong light-matter coupling is shown to lead to almost total absorption at two distinct frequencies.

Constraints on light mediators: Confronting dark matter searches with B physics

NASA Astrophysics Data System (ADS)

Schmidt-Hoberg, Kai; Staub, Florian; Winkler, Martin Wolfgang

2013-12-01

Light scalars appear in many well-motivated extensions of the Standard Model including supersymmetric models with additional gauge singlets. Such scalars could mediate the interactions between dark matter and nuclei, giving rise to the tentative signals observed by several dark matter direct detection experiments including CDMS-Si. In this Letter, we derive strong new limits on light scalar mediators by using the LHCb, Belle and BaBar searches for rare ϒ and B decays. These limits rule out significant parts of the parameter space favored by CDMS-Si. Nevertheless, as current searches are not optimized for investigating weakly coupled light scalars, a further increase in experimental sensitivity could be achieved by relaxing requirements in the event selection.

Isocurvature constraints on portal couplings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kainulainen, Kimmo; Nurmi, Sami; Vaskonen, Ville

2016-06-01

We consider portal models which are ultraweakly coupled with the Standard Model, and confront them with observational constraints on dark matter abundance and isocurvature perturbations. We assume the hidden sector to contain a real singlet scalar s and a sterile neutrino ψ coupled to s via a pseudoscalar Yukawa term. During inflation, a primordial condensate consisting of the singlet scalar s is generated, and its contribution to the isocurvature perturbations is imprinted onto the dark matter abundance. We compute the total dark matter abundance including the contributions from condensate decay and nonthermal production from the Standard Model sector. We thenmore » use the Planck limit on isocurvature perturbations to derive a novel constraint connecting dark matter mass and the singlet self coupling with the scale of inflation: m {sub DM}/GeV ∼< 0.2λ{sub s}{sup 3/8} ( H {sub *}/10{sup 11} GeV){sup −3/2}. This constraint is relevant in most portal models ultraweakly coupled with the Standard Model and containing light singlet scalar fields.« less

Towards manipulating relativistic laser pulses with micro-tube plasma lenses

PubMed Central

Ji, L. L.; Snyder, J.; Pukhov, A.; Freeman, R. R.; Akli, K. U.

2016-01-01

Efficient coupling of intense laser pulses to solid-density matter is critical to many applications including ion acceleration for cancer therapy. At relativistic intensities, the focus has been mainly on investigating various laser beams irradiating initially overdense flat interfaces with little or no control over the interaction. Here, we propose a novel approach that leverages recent advancements in 3D direct laser writing (DLW) of materials and high contrast lasers to manipulate the laser-matter interactions on the micro-scales. We demonstrate, via simulations, that usable intensities ≥1023 Wcm−2 could be achieved with current tabletop lasers coupled to micro-engineered plasma lenses. We show that these plasma optical elements act as a lens to focus laser light. These results open new paths to engineering light-matter interactions at ultra-relativistic intensities. PMID:26979657

Ultrastrong composite film of Chitosan and silica-coated graphene oxide sheets.

PubMed

Yan, Haichen; Jiang, Lei; Xu, Xiaozhou; Li, Yanbao; Shen, Yuesong; Zhu, Shemin

2017-11-01

Chitosan (CS) has attracted significant interest in various fields due to its outstanding functional properties (especially, its chain with positive charge). However, wide-range applications of CS are severely limited because of its poor mechanical properties. Ultrastrong composite film of CS and silica-coated graphene oxide sheets (GO@SiO 2 ) were prepared by a simple solution casting method in this article. GO@SiO 2 was prepared by the hydrolysis of tetraethyl orthosilicate (TEOS) in GO ethanol solution. Compared with the pure CS film, the tensile strength of the CS/GO@SiO 2 composite film with incorporation of 1.75wt% GO@SiO 2 fillers was significantly increased 158% from 55±4 to 142±24MPa. Such high tensile strength may be caused synergistically by strong interaction between two components and high crystallinity of the CS matrix. CS based composite with ultrastrong strength may have more potential applications in biomedical fields. Copyright © 2017 Elsevier B.V. All rights reserved.

Light clusters and pasta phases in warm and dense nuclear matter

NASA Astrophysics Data System (ADS)

Avancini, Sidney S.; Ferreira, Márcio; Pais, Helena; Providência, Constança; Röpke, Gerd

2017-04-01

The pasta phases are calculated for warm stellar matter in a framework of relativistic mean-field models, including the possibility of light cluster formation. Results from three different semiclassical approaches are compared with a quantum statistical calculation. Light clusters are considered as point-like particles, and their abundances are determined from the minimization of the free energy. The couplings of the light clusters to mesons are determined from experimental chemical equilibrium constants and many-body quantum statistical calculations. The effect of these light clusters on the chemical potentials is also discussed. It is shown that, by including heavy clusters, light clusters are present up to larger nucleonic densities, although with smaller mass fractions.

Sterile neutrinos in cosmology

NASA Astrophysics Data System (ADS)

Abazajian, Kevork N.

2017-11-01

Sterile neutrinos are natural extensions to the standard model of particle physics in neutrino mass generation mechanisms. If they are relatively light, less than approximately 10 keV, they can alter cosmology significantly, from the early Universe to the matter and radiation energy density today. Here, we review the cosmological role such light sterile neutrinos can play from the early Universe, including production of keV-scale sterile neutrinos as dark matter candidates, and dynamics of light eV-scale sterile neutrinos during the weakly-coupled active neutrino era. We review proposed signatures of light sterile neutrinos in cosmic microwave background and large scale structure data. We also discuss keV-scale sterile neutrino dark matter decay signatures in X-ray observations, including recent candidate ∼3.5 keV X-ray line detections consistent with the decay of a ∼7 keV sterile neutrino dark matter particle.

Quantum State Reduction by Matter-Phase-Related Measurements in Optical Lattices

PubMed Central

Kozlowski, Wojciech; Caballero-Benitez, Santiago F.; Mekhov, Igor B.

2017-01-01

A many-body atomic system coupled to quantized light is subject to weak measurement. Instead of coupling light to the on-site density, we consider the quantum backaction due to the measurement of matter-phase-related variables such as global phase coherence. We show how this unconventional approach opens up new opportunities to affect system evolution. We demonstrate how this can lead to a new class of final states different from those possible with dissipative state preparation or conventional projective measurements. These states are characterised by a combination of Hamiltonian and measurement properties thus extending the measurement postulate for the case of strong competition with the system’s own evolution. PMID:28225012

Quantum State Reduction by Matter-Phase-Related Measurements in Optical Lattices.

PubMed

Kozlowski, Wojciech; Caballero-Benitez, Santiago F; Mekhov, Igor B

2017-02-22

A many-body atomic system coupled to quantized light is subject to weak measurement. Instead of coupling light to the on-site density, we consider the quantum backaction due to the measurement of matter-phase-related variables such as global phase coherence. We show how this unconventional approach opens up new opportunities to affect system evolution. We demonstrate how this can lead to a new class of final states different from those possible with dissipative state preparation or conventional projective measurements. These states are characterised by a combination of Hamiltonian and measurement properties thus extending the measurement postulate for the case of strong competition with the system's own evolution.

Mechanistic Origin of the Ultrastrong Adhesion between Graphene and a-SiO2: Beyond van der Waals.

PubMed

Kumar, Sandeep; Parks, David; Kamrin, Ken

2016-07-26

The origin of the ultrastrong adhesion between graphene and a-SiO2 has remained a mystery. This adhesion is believed to be predominantly van der Waals (vdW) in nature. By rigorously analyzing recently reported blistering and nanoindentation experiments, we show that the ultrastrong adhesion between graphene and a-SiO2 cannot be attributed to vdW forces alone. Our analyses show that the fracture toughness of the graphene/a-SiO2 interface, when the interfacial adhesion is modeled with vdW forces alone, is anomalously weak compared to the measured values. The anomaly is related to an ultrasmall fracture process zone (FPZ): owing to the lack of a third dimension in graphene, the FPZ for the graphene/a-SiO2 interface is extremely small, and the combination of predominantly tensile vdW forces, distributed over such a small area, is bound to result in a correspondingly small interfacial fracture toughness. Through multiscale modeling, combining the results of finite element analysis and molecular dynamics simulations, we show that the adhesion between graphene and a-SiO2 involves two different kinds of interactions: one, a weak, long-range interaction arising from vdW adhesion and, second, discrete, short-range interactions originating from graphene clinging to the undercoordinated Si (≡Si·) and the nonbridging O (≡Si-O·) defects on a-SiO2. A strong resistance to relative opening and sliding provided by the latter mechanism is identified as the operative mechanism responsible for the ultrastrong adhesion between graphene and a-SiO2.

Dark matter with pseudoscalar-mediated interactions explains the DAMA signal and the galactic center excess.

PubMed

Arina, Chiara; Del Nobile, Eugenio; Panci, Paolo

2015-01-09

We study a Dirac dark matter particle interacting with ordinary matter via the exchange of a light pseudoscalar, and analyze its impact on both direct and indirect detection experiments. We show that this candidate can accommodate the long-standing DAMA modulated signal and yet be compatible with all exclusion limits at 99(S)% C.L. This result holds for natural choices of the pseudoscalar-quark couplings (e.g., flavor universal), which give rise to a significant enhancement of the dark matter-proton coupling with respect to the coupling to neutrons. We also find that this candidate can accommodate the observed 1-3 GeV gamma-ray excess at the Galactic center and at the same time have the correct relic density today. The model could be tested with measurements of rare meson decays, flavor changing processes, and searches for axionlike particles with mass in the MeV range.

Scalar dark matter in leptophilic two-Higgs-doublet model

NASA Astrophysics Data System (ADS)

Bandyopadhyay, Priyotosh; Chun, Eung Jin; Mandal, Rusa

2018-04-01

Two-Higgs-Doublet Model of Type-X in the large tan ⁡ β limit becomes leptophilic to allow a light pseudo-scalar A and thus provides an explanation of the muon g - 2 anomaly. Introducing a singlet scalar dark matter S in this context, one finds that two important dark matter properties, nucleonic scattering and self-annihilation, are featured separately by individual couplings of dark matter to the two Higgs doublets. While one of the two couplings is strongly constrained by direct detection experiments, the other remains free to be adjusted for the relic density mainly through the process SS → AA. This leads to the 4τ final states which can be probed by galactic gamma ray detections.

Coupling nonlinear optical waves to photoreactive and phase-separating soft matter: Current status and perspectives

NASA Astrophysics Data System (ADS)

Biria, Saeid; Morim, Derek R.; An Tsao, Fu; Saravanamuttu, Kalaichelvi; Hosein, Ian D.

2017-10-01

Nonlinear optics and polymer systems are distinct fields that have been studied for decades. These two fields intersect with the observation of nonlinear wave propagation in photoreactive polymer systems. This has led to studies on the nonlinear dynamics of transmitted light in polymer media, particularly for optical self-trapping and optical modulation instability. The irreversibility of polymerization leads to permanent capture of nonlinear optical patterns in the polymer structure, which is a new synthetic route to complex structured soft materials. Over time more intricate polymer systems are employed, whereby nonlinear optical dynamics can couple to nonlinear chemical dynamics, opening opportunities for self-organization. This paper discusses the work to date on nonlinear optical pattern formation processes in polymers. A brief overview of nonlinear optical phenomenon is provided to set the stage for understanding their effects. We review the accomplishments of the field on studying nonlinear waveform propagation in photopolymerizable systems, then discuss our most recent progress in coupling nonlinear optical pattern formation to polymer blends and phase separation. To this end, perspectives on future directions and areas of sustained inquiry are provided. This review highlights the significant opportunity in exploiting nonlinear optical pattern formation in soft matter for the discovery of new light-directed and light-stimulated materials phenomenon, and in turn, soft matter provides a platform by which new nonlinear optical phenomenon may be discovered.

Vector SIMP dark matter

DOE PAGES

Choi, Soo -Min; Hochberg, Yonit; Kuflik, Eric; ...

2017-10-24

Strongly Interacting Massive Particles (SIMPs) have recently been proposed as light thermal dark matter relics. Here we consider an explicit realization of the SIMP mechanism in the form of vector SIMPs arising from an SU(2) X hidden gauge theory, where the accidental custodial symmetry protects the stability of the dark matter. We propose several ways of equilibrating the dark and visible sectors in this setup. In particular, we show that a light dark Higgs portal can maintain thermal equilibrium between the two sectors, as can a massive dark vector portal with its generalized Chern-Simons couplings to the vector SIMPs, allmore » while remaining consistent with experimental constraints.« less

Vector SIMP dark matter

NASA Astrophysics Data System (ADS)

Choi, Soo-Min; Hochberg, Yonit; Kuflik, Eric; Lee, Hyun Min; Mambrini, Yann; Murayama, Hitoshi; Pierre, Mathias

2017-10-01

Strongly Interacting Massive Particles (SIMPs) have recently been proposed as light thermal dark matter relics. Here we consider an explicit realization of the SIMP mechanism in the form of vector SIMPs arising from an SU(2) X hidden gauge theory, where the accidental custodial symmetry protects the stability of the dark matter. We propose several ways of equilibrating the dark and visible sectors in this setup. In particular, we show that a light dark Higgs portal can maintain thermal equilibrium between the two sectors, as can a massive dark vector portal with its generalized Chern-Simons couplings to the vector SIMPs, all while remaining consistent with experimental constraints.

Vector SIMP dark matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Soo -Min; Hochberg, Yonit; Kuflik, Eric

Strongly Interacting Massive Particles (SIMPs) have recently been proposed as light thermal dark matter relics. Here we consider an explicit realization of the SIMP mechanism in the form of vector SIMPs arising from an SU(2) X hidden gauge theory, where the accidental custodial symmetry protects the stability of the dark matter. We propose several ways of equilibrating the dark and visible sectors in this setup. In particular, we show that a light dark Higgs portal can maintain thermal equilibrium between the two sectors, as can a massive dark vector portal with its generalized Chern-Simons couplings to the vector SIMPs, allmore » while remaining consistent with experimental constraints.« less

Nanofocusing of structured light for quadrupolar light-matter interactions.

PubMed

Sakai, Kyosuke; Yamamoto, Takeaki; Sasaki, Keiji

2018-05-17

The spatial structure of an electromagnetic field can determine the characteristics of light-matter interactions. A strong gradient of light in the near field can excite dipole-forbidden atomic transitions, e.g., electric quadrupole transitions, which are rarely observed under plane-wave far-field illumination. Structured light with a higher-order orbital angular momentum state may also modulate the selection rules in which an atom can absorb two quanta of angular momentum: one from the spin and another from the spatial structure of the beam. Here, we numerically demonstrate a strong focusing of structured light with a higher-order orbital angular momentum state in the near field. A quadrupole field was confined within a gap region of several tens of nanometres in a plasmonic tetramer structure. A plasmonic crystal surrounding the tetramer structure provides a robust antenna effect, where the incident structured light can be strongly coupled to the quadrupole field in the gap region with a larger alignment tolerance. The proposed system is expected to provide a platform for light-matter interactions with strong multipolar effects.

WIMP-less dark matter and meson decays with missing energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

McKeen, David

2009-06-01

WIMP-less dark matter [J. L. Feng and J. Kumar, Phys. Rev. Lett. 101, 231301 (2008).] offers an attractive framework in which dark matter can be very light. We investigate the implications of such scenarios on invisible decays of bottomonium states for dark matter with a mass less than around 5 GeV. We relate these decays to measurements of nucleon-dark matter elastic scattering. We also investigate the effect that a coupling to s quarks has on flavor changing b{yields}s processes involving missing energy.

Plasmonic Antenna Coupling for QWIPs

NASA Technical Reports Server (NTRS)

Hong, John

2007-01-01

In a proposed scheme for coupling light into a quantum-well infrared photodetector (QWIP), an antenna or an array of antennas made of a suitable metal would be fabricated on the face of what would otherwise be a standard QWIP. This or any such coupling scheme is required to effect polarization conversion: Light incident perpendicularly to the face is necessarily polarized in the plane of the face, whereas, as a matter of fundamental electrodynamics and related quantum selection rules, light must have a non-zero component of perpendicular polarization in order to be absorbed in the photodetection process. In a prior coupling scheme, gratings in the form of surface corrugations diffract normally gles, thereby imparting some perpendicular polarization. Unfortunately, the corrugation- fabrication process increases the overall nonuniformity of a large QWIP array. The proposed scheme is an alternative to the use of surface corrugations.

Flooded Dark Matter and S level rise

NASA Astrophysics Data System (ADS)

Randall, Lisa; Scholtz, Jakub; Unwin, James

2016-03-01

Most dark matter models set the dark matter relic density by some interaction with Standard Model particles. Such models generally assume the existence of Standard Model particles early on, with the dark matter relic density a later consequence of those interactions. Perhaps a more compelling assumption is that dark matter is not part of the Standard Model sector and a population of dark matter too is generated at the end of inflation. This democratic assumption about initial conditions does not necessarily provide a natural value for the dark matter relic density, and furthermore superficially leads to too much entropy in the dark sector relative to ordinary matter. We address the latter issue by the late decay of heavy particles produced at early times, thereby associating the dark matter relic density with the lifetime of a long-lived state. This paper investigates what it would take for this scenario to be compatible with observations in what we call Flooded Dark Matter (FDM) models and discusses several interesting consequences. One is that dark matter can be very light and furthermore, light dark matter is in some sense the most natural scenario in FDM as it is compatible with larger couplings of the decaying particle. A related consequence is that the decay of the field with the smallest coupling and hence the longest lifetime dominates the entropy and possibly the matter content of the Universe, a principle we refer to as "Maximum Baroqueness". We also demonstrate that the dark sector should be colder than the ordinary sector, relaxing the most stringent free-streaming constraints on light dark matter candidates. We will discuss the potential implications for the core-cusp problem in a follow-up paper. The FDM framework will furthermore have interesting baryogenesis implications. One possibility is that dark matter is like the baryon asymmetry and both are simultaneously diluted by a late entropy dump. Alternatively, FDM is compatible with an elegant non-thermal leptogenesis implementation in which decays of a heavy right-handed neutrino lead to late time reheating of the Standard Model degrees of freedom and provide suitable conditions for creation of a lepton asymmetry.

Perfect absorption of modified-molybdenum-disulfide-based Tamm plasmonic structures

NASA Astrophysics Data System (ADS)

Wang, Xiaoyu; Wang, Jicheng; Hu, Zheng-Da; Sang, Tian; Feng, Yan

2018-06-01

The two-dimensional semiconductor materials of transition metal molybdenum disulfide display various special optical properties in the interaction of matter and light. In this work, we study the strong coupling between the two-dimensional materials’ excitons and Tamm plasmon polaritons (TPPs). To enhance the interaction between light and matter, we introduce the grating modulation in the traditional Tamm structure. By adjusting the structure parameters of the grating-modified Tamm system, we achieve perfect absorption in the visible region. Our research results will pave the way for the application of ultrathin polarization optical devices.

Quantum Photonic in Hybrid Cavity Systems with Strong Matter-Light Couplings

DTIC Science & Technology

2015-08-24

properties. [Ref 1, 6] 2. Confinement and coupling of microcavity polaritons were readily implemented by design of the photonic crystal in the new...cavity structure, allowing flexible device design and integration of the polariton system. Zero-dimensional polariton systems were created by reducing...the area of the photonic crystal, coupling between multiple zero-dimensional polariton systems was controlled by design of the boundaries of the

Quantum Photonic in Hybrid Cavity Systems with Strong Matter-Light Couplings

DTIC Science & Technology

2015-08-24

applications of property-designed quantum liquids. Specifically the following was achieved: 1. Strong-coupling between quantum-well excitons and cavity...designed quantum liquids. Specifically the following was achieved: 1. Strong-coupling between quantum-well excitons and cavity photons was demonstrated...J., Brodbeck, S., Zhang, B., Wang, Z., Worschech, L., Deng, H., Kamp, M., Schneider, C. & Höfling, S. “Magneto- exciton -polariton condensation in a

Polariton condensation with saturable molecules dressed by vibrational modes

DOE PAGES

Cwik, Justyna A.; Reja, Sahinur; Littlewood, Peter B.; ...

2014-02-01

Here, polaritons, mixed light-matter quasiparticles, undergo a transition to a condensed, macroscopically coherent state at low temperatures or high densities. Recent experiments show that coupling light to organic molecules inside a microcavity allows condensation at room temperature. The molecules act as saturable absorbers with transitions dressed by molecular vibrational modes. Motivated by this, we calculate the phase diagram and spectrum of a modified Tavis-Cummings model, describing vibrationally dressed two-level systems, coupled to a cavity mode. Coupling to vibrational modes can induce re-entrance, i.e. a normal-condensed-normal sequence with decreasing temperature and can drive the transition first-order.

Recipe for Topological Polaritons

NASA Astrophysics Data System (ADS)

Karzig, Torsten; Bardyn, Charles-Edouard; Lindner, Netanel; Refael, Gil

2015-03-01

The interaction between light and matter can give rise to novel topological states. This principle was recently exemplified in Floquet topological insulators, where classical light was used to induce a topological electronic band structure. Here, in contrast, we show that mixing single photons with excitons can result in new topological polaritonic states -- or ``topolaritons''. Taken separately, the underlying photons and excitons are topologically trivial. Combined appropriately, however, they give rise to non-trivial polaritonic bands with chiral edge modes allowing for unidirectional polariton propagation. The main ingredient in our construction is an exciton-photon coupling with a phase that winds in momentum space. We demonstrate how this winding emerges from spin-orbit coupling in the electronic system and an applied Zeeman field. We discuss the requirements for obtaining a sizable topological gap in the polariton spectrum. Funded by the Institute for Quantum Information and Matter, the Bi-National Science Foundation and I-Core: the Israeli Excellence Center ``Circle of Light'', and Darpa under funding for FENA, and the Swiss National Science Foundation.

Plasmonic mode converter for controlling optical impedance and nanoscale light-matter interaction.

PubMed

Hung, Yun-Ting; Huang, Chen-Bin; Huang, Jer-Shing

2012-08-27

To enable multiple functions of plasmonic nanocircuits, it is of key importance to control the propagation properties and the modal distribution of the guided optical modes such that their impedance matches to that of nearby quantum systems and desired light-matter interaction can be achieved. Here, we present efficient mode converters for manipulating guided modes on a plasmonic two-wire transmission line. The mode conversion is achieved through varying the path length, wire cross section and the surrounding index of refraction. Instead of pure optical interference, strong near-field coupling of surface plasmons results in great momentum splitting and modal profile variation. We theoretically demonstrate control over nanoantenna radiation and discuss the possibility to enhance nanoscale light-matter interaction. The proposed converter may find applications in surface plasmon amplification, index sensing and enhanced nanoscale spectroscopy.

Integral equation and discontinuous Galerkin methods for the analysis of light-matter interaction

NASA Astrophysics Data System (ADS)

Baczewski, Andrew David

Light-matter interaction is among the most enduring interests of the physical sciences. The understanding and control of this physics is of paramount importance to the design of myriad technologies ranging from stained glass, to molecular sensing and characterization techniques, to quantum computers. The development of complex engineered systems that exploit this physics is predicated at least partially upon in silico design and optimization that properly capture the light-matter coupling. In this thesis, the details of computational frameworks that enable this type of analysis, based upon both Integral Equation and Discontinuous Galerkin formulations will be explored. There will be a primary focus on the development of efficient and accurate software, with results corroborating both. The secondary focus will be on the use of these tools in the analysis of a number of exemplary systems.

Ultra-low-power hybrid light-matter solitons.

PubMed

Walker, P M; Tinkler, L; Skryabin, D V; Yulin, A; Royall, B; Farrer, I; Ritchie, D A; Skolnick, M S; Krizhanovskii, D N

2015-09-24

New functionalities in nonlinear optics will require systems with giant optical nonlinearity as well as compatibility with photonic circuit fabrication techniques. Here we introduce a platform based on strong light-matter coupling between waveguide photons and quantum-well excitons. On a sub-millimetre length scale we generate picosecond bright temporal solitons at a pulse energy of only 0.5 pJ. From this we deduce a nonlinear refractive index three orders of magnitude larger than in any other ultrafast system. We study both temporal and spatio-temporal nonlinear effects and observe dark-bright spatio-temporal polariton solitons. Theoretical modelling of soliton formation in the strongly coupled system confirms the experimental observations. These results show the promise of our system as a high speed, low power, integrated platform for physics and devices based on strong interactions between photons.

Quantum ring with the Rashba spin-orbit interaction in the regime of strong light-matter coupling

NASA Astrophysics Data System (ADS)

Kozin, V. K.; Iorsh, I. V.; Kibis, O. V.; Shelykh, I. A.

2018-04-01

We developed the theory of electronic properties of semiconductor quantum rings with the Rashba spin-orbit interaction irradiated by an off-resonant high-frequency electromagnetic field (dressing field). Within the Floquet theory of periodically driven quantum systems, it is demonstrated that the dressing field drastically modifies all electronic characteristics of the rings, including spin-orbit coupling, effective electron mass, and optical response. In particular, the present effect paves the way to controlling the spin polarization of electrons with light in prospective ring-shaped spintronic devices.

Voltage‐Controlled Switching of Strong Light–Matter Interactions using Liquid Crystals

PubMed Central

Hertzog, Manuel; Rudquist, Per; Hutchison, James A.; George, Jino; Ebbesen, Thomas W.

2017-01-01

Abstract We experimentally demonstrate a fine control over the coupling strength of vibrational light–matter hybrid states by controlling the orientation of a nematic liquid crystal. Through an external voltage, the liquid crystal is seamlessly switched between two orthogonal directions. Using these features, for the first time, we demonstrate electrical switching and increased Rabi splitting through transition dipole moment alignment. The C−Nstr vibration on the liquid crystal molecule is coupled to a cavity mode, and FT‐IR is used to probe the formed vibropolaritonic states. A switching ratio of the Rabi splitting of 1.78 is demonstrated between the parallel and the perpendicular orientation. Furthermore, the orientational order increases the Rabi splitting by 41 % as compared to an isotropic liquid. Finally, by examining the influence of molecular alignment on the Rabi splitting, the scalar product used in theoretical modeling between light and matter in the strong coupling regime is verified. PMID:29155469

Influence of Surface Roughness on Strong Light-Matter Interaction of a Quantum Emitter-Metallic Nanoparticle System.

PubMed

Lu, Yu-Wei; Li, Ling-Yan; Liu, Jing-Feng

2018-05-08

We investigate the quantum optical properties of strong light-matter interaction between a quantum emitter and a metallic nanoparticle beyond idealized structures with a smooth surface. Based on the local coupling strength and macroscopic Green's function, we derived an exact quantum optics approach to obtain the field enhancement and light-emission spectrum of a quantum emitter. Numerical simulations show that the surface roughness has a greater effect on the near-field than on the far-field, and slightly increases the vacuum Rabi splitting on average. Further, we verified that the near-field enhancement is mainly determined by the surface features of hot-spot area.

Creation of quantum steering by interaction with a common bath

NASA Astrophysics Data System (ADS)

Sun, Zhe; Xu, Xiao-Qiang; Liu, Bo

2018-05-01

By applying the hierarchy equation method, we computationally study the creation of quantum steering in a two-qubit system interacting with a common bosonic bath. The calculation does not adopt conventional approximate approaches, such as the Born, Markov, rotating-wave, and other perturbative approximations. Three kinds of quantum steering, i.e., Einstein-Podolsky-Rosen steering (EPRS), temporal steering (TS), and spatiotemporal steering (STS), are considered. Since the initial state of the two qubits is chosen as a product state, there does not exist EPRS at the beginning. During the evolution, we find that STS as well as EPRS are generated at the same time. An inversion relationship between STS and TS is revealed. By varying the system-bath coupling strength from weak to ultrastrong regimes, we find the nonmonotonic dependence of STS, TS, and EPRS on the coupling strength. It is interesting to study the dynamics of the three kinds of quantum steering by using an exactly numerical method, which is not considered in previous researches.

Detection of light-matter interaction in the weak-coupling regime by quantum light

NASA Astrophysics Data System (ADS)

Bin, Qian; Lü, Xin-You; Zheng, Li-Li; Bin, Shang-Wu; Wu, Ying

2018-04-01

"Mollow spectroscopy" is a photon statistics spectroscopy, obtained by scanning the quantum light scattered from a source system. Here, we apply this technique to detect the weak light-matter interaction between the cavity and atom (or a mechanical oscillator) when the strong system dissipation is included. We find that the weak interaction can be measured with high accuracy when exciting the target cavity by quantum light scattered from the source halfway between the central peak and each side peak. This originally comes from the strong correlation of the injected quantum photons. In principle, our proposal can be applied into the normal cavity quantum electrodynamics system described by the Jaynes-Cummings model and an optomechanical system. Furthermore, it is state of the art for experiment even when the interaction strength is reduced to a very small value.

M$^3$: A New Muon Missing Momentum Experiment to Probe $$(g-2)_{\\mu}$$ and Dark Matter at Fermilab

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kahn, Yonatan; Krnjaic, Gordan; Tran, Nhan

New light, weakly-coupled particles are commonly invoked to address the persistentmore » $$\\sim 4\\sigma$$ anomaly in $$(g-2)_\\mu$$ and serve as mediators between dark and visible matter. If such particles couple predominantly to heavier generations and decay invisibly, much of their best-motivated parameter space is inaccessible with existing experimental techniques. In this paper, we present a new fixed-target, missing-momentum search strategy to probe invisibly decaying particles that couple preferentially to muons. In our setup, a relativistic muon beam impinges on a thick active target. The signal consists of events in which a muon loses a large fraction of its incident momentum inside the target without initiating any detectable electromagnetic or hadronic activity in downstream veto systems. We propose a two-phase experiment, M$^3$ (Muon Missing Momentum), based at Fermilab. Phase 1 with $$\\sim 10^{10}$$ muons on target can test the remaining parameter space for which light invisibly-decaying particles can resolve the $$(g-2)_\\mu$$ anomaly, while Phase 2 with $$\\sim 10^{13}$$ muons on target can test much of the predictive parameter space over which sub-GeV dark matter achieves freeze-out via muon-philic forces, including gauged $$U(1)_{L_\\mu - L_\\tau}$$.« less

MoS2 monolayers on nanocavities: enhancement in light-matter interaction

NASA Astrophysics Data System (ADS)

Janisch, Corey; Song, Haomin; Zhou, Chanjing; Lin, Zhong; Elías, Ana Laura; Ji, Dengxin; Terrones, Mauricio; Gan, Qiaoqiang; Liu, Zhiwen

2016-06-01

Two-dimensional (2D) atomic crystals and van der Waals heterostructures constitute an emerging platform for developing new functional ultra-thin electronic and optoelectronic materials for novel energy-efficient devices. However, in most thin-film optical applications, there is a long-existing trade-off between the effectiveness of light-matter interactions and the thickness of semiconductor materials, especially when the materials are scaled down to atom thick dimensions. Consequently, enhancement strategies can introduce significant advances to these atomically thick materials and devices. Here we demonstrate enhanced absorption and photoluminescence generation from MoS2 monolayers coupled with a planar nanocavity. This nanocavity consists of an alumina nanolayer spacer sandwiched between monolayer MoS2 and an aluminum reflector, and can strongly enhance the light-matter interaction within the MoS2, increasing the exclusive absorption of monolayer MoS2 to nearly 70% at a wavelength of 450 nm. The nanocavity also modifies the spontaneous emission rate, providing an additional design freedom to control the interaction between light and 2D materials.

Probing GeV-scale MSSM neutralino dark matter in collider and direct detection experiments

NASA Astrophysics Data System (ADS)

Duan, Guang Hua; Wang, Wenyu; Wu, Lei; Yang, Jin Min; Zhao, Jun

2018-03-01

Given the recent constraints from the dark matter (DM) direct detections, we examine a light GeV-scale (2-30 GeV) neutralino DM in the alignment limit of the Minimal Supersymmetric Standard Model (MSSM). In this limit without decoupling, the heavy CP-even scalar H plays the role of the Standard Model (SM) Higgs boson while the other scalar h can be rather light so that the DM can annihilate through the h resonance or into a pair of h to achieve the observed relic density. With the current collider and cosmological constraints, we find that such a light neutralino DM above 6 GeV can be excluded by the XENON-1T (2017) limits while the survivied parameter space below 6 GeV can be fully tested by the future germanium-based light dark matter detections (such as CDEX), by the Higgs coupling precison measurements or by the production process e+e- → hA at an electron-positron collider (Higgs factory).

Analytic few-photon scattering in waveguide QED

NASA Astrophysics Data System (ADS)

Hurst, David L.; Kok, Pieter

2018-04-01

We develop an approach to light-matter coupling in waveguide QED based upon scattering amplitudes evaluated via Dyson series. For optical states containing more than single photons, terms in this series become increasingly complex, and we provide a diagrammatic recipe for their evaluation, which is capable of yielding analytic results. Our method fully specifies a combined emitter-optical state that permits investigation of light-matter entanglement generation protocols. We use our expressions to study two-photon scattering from a Λ -system and find that the pole structure of the transition amplitude is dramatically altered as the two ground states are tuned from degeneracy.

Controllable vacuum-induced diffraction of matter-wave superradiance using an all-optical dispersive cavity

NASA Astrophysics Data System (ADS)

Su, Shih-Wei; Lu, Zhen-Kai; Gou, Shih-Chuan; Liao, Wen-Te

2016-10-01

Cavity quantum electrodynamics (CQED) has played a central role in demonstrating the fundamental principles of the quantum world, and in particular those of atom-light interactions. Developing fast, dynamical and non-mechanical control over a CQED system is particularly desirable for controlling atomic dynamics and building future quantum networks at high speed. However conventional mirrors do not allow for such flexible and fast controls over their coupling to intracavity atoms mediated by photons. Here we theoretically investigate a novel all-optical CQED system composed of a binary Bose-Einstein condensate (BEC) sandwiched by two atomic ensembles. The highly tunable atomic dispersion of the CQED system enables the medium to act as a versatile, all-optically controlled atomic mirror that can be employed to manipulate the vacuum-induced diffraction of matter-wave superradiance. Our study illustrates a innovative all-optical element of atomtroics and sheds new light on controlling light-matter interactions.

Group electronegativity for prediction of materials hardness.

PubMed

Li, Keyan; Yang, Peng; Niu, Lingxiao; Xue, Dongfeng

2012-06-28

We have developed a method to predict the hardness of materials containing ultrastrong anionic polyhedra, dense atomic clusters, and layers stacked through van der Waals bonds on the basis of group electronegativity. By considering these polyhedra, clusters, and layers as groups that behave as rigid unities like superatoms bonding to other atoms or groups, the hardness values of materials such as oxysalts, T-carbon, and graphite were quantitatively calculated, and the results are consistent with the available experiments. We found that the hardness of materials containing these artificial groups is determined by the bonds between the groups and other atoms or groups, rather than by the weakest bonds. This work sheds light on the nature of materials hardness and the design of novel inorganic crystal materials.

Atmospheric Light Detection and Ranging (LiDAR) Coupled With Point Measurement Air Quality Samplers to Measure Fine Particulate Matter (PM) Emissions From Agricultural Operations: The Los Banos CA Fall 2007 Tillage Campaign.

EPA Science Inventory

Airborne particles, especially fine particulate matter 2.5 micrometers (μm) or less in aerodynamic diameter (PM2.5), are microscopic solids or liquid droplets that can cause serious health problems, including increased respiratory symptoms such as coughing or difficulty breathing...

Photoinduced Electron Transfer in the Strong Coupling Regime: Waveguide-Plasmon Polaritons.

PubMed

Zeng, Peng; Cadusch, Jasper; Chakraborty, Debadi; Smith, Trevor A; Roberts, Ann; Sader, John E; Davis, Timothy J; Gómez, Daniel E

2016-04-13

Reversible exchange of photons between a material and an optical cavity can lead to the formation of hybrid light-matter states where material properties such as the work function [ Hutchison et al. Adv. Mater. 2013 , 25 , 2481 - 2485 ], chemical reactivity [ Hutchison et al. Angew. Chem., Int. Ed. 2012 , 51 , 1592 - 1596 ], ultrafast energy relaxation [ Salomon et al. Angew. Chem., Int. Ed. 2009 , 48 , 8748 - 8751 ; Gomez et al. J. Phys. Chem. B 2013 , 117 , 4340 - 4346 ], and electrical conductivity [ Orgiu et al. Nat. Mater. 2015 , 14 , 1123 - 1129 ] of matter differ significantly to those of the same material in the absence of strong interactions with the electromagnetic fields. Here we show that strong light-matter coupling between confined photons on a semiconductor waveguide and localized plasmon resonances on metal nanowires modifies the efficiency of the photoinduced charge-transfer rate of plasmonic derived (hot) electrons into accepting states in the semiconductor material. Ultrafast spectroscopy measurements reveal a strong correlation between the amplitude of the transient signals, attributed to electrons residing in the semiconductor and the hybridization of waveguide and plasmon excitations.

Environments of strong/ultrastrong, ultraviolet Fe II emitting quasars

NASA Astrophysics Data System (ADS)

Clowes, Roger G.; Raghunathan, Srinivasan; Söchting, Ilona K.; Graham, Matthew J.; Campusano, Luis E.

2013-08-01

We have investigated the strength of ultraviolet (UV) Fe II emission from quasars within the environments of large quasar groups (LQGs) in comparison with quasars elsewhere, for 1.1 ≤ zLQG ≤ 1.7, using the DR7QSO catalogue of the Sloan Digital Sky Survey. We use the Weymann et al. W2400 equivalent width, defined between the rest-frame continuum windows 2240-2255 and 2665-2695 Å, as the measure of the UV Fe II emission. We find a significant shift of the W2400 distribution to higher values for quasars within LQGs, predominantly for those LQGs with 1.1 ≤ zLQG ≤ 1.5. There is a tentative indication that the shift to higher values increases with the quasar i magnitude. We find evidence that within LQGs the ultrastrong emitters with W2400 ≥ 45 Å (more precisely, ultrastrong plus with W2400 ≥ 44 Å) have preferred nearest-neighbour separations of ˜30-50 Mpc to the adjacent quasar of any W2400 strength. No such effect is seen for the ultrastrong emitters that are not in LQGs. The possibilities for increasing the strength of the Fe II emission appear to be iron abundance, Lyα fluorescence and microturbulence, and probably all of these operate. The dense environment of the LQGs may have led to an increased rate of star formation and an enhanced abundance of iron in the nuclei of galaxies. Similarly, the dense environment may have led to more active blackholes and increased Lyα fluorescence. The preferred nearest-neighbour separation for the stronger emitters would appear to suggest a dynamical component, such as microturbulence. In one particular LQG, the Huge-LQG (the largest structure known in the early Universe), six of the seven strongest emitters very obviously form three pairings within the total of 73 members.

A large-area, wide-incident-angle, and polarization-independent plasmonic color filter for glucose sensing

NASA Astrophysics Data System (ADS)

Lin, Yu-Sheng; Chen, Wenjun

2018-01-01

We develop an effective method for glucose sensing by using a plasmonic color filter (PCF) integrated with a microfluidic chip. The morphology of PCF is composed of hybrid nanopillars fabricated with SiO2 and Au thin-films on silicon substrate. It exhibits angle-independence, polarization-independence and wafer-level fabrication, which are the most important factors for color filters for industrial applications. The shift of resonant wavelength is 56 nm with a stable bandwidth (∼30 nm) by varying concentration of glucose solution. The sensitivity is 157.61 nm/RIU and the corresponding figure-of-merit is 5.25. Such strategy can be exploited to further increase the detection and potentially enter the ultra-strong coupling regime in chemical solution sensors.

Dark matter self-interactions from a general spin-0 mediator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kahlhoefer, Felix; Schmidt-Hoberg, Kai; Wild, Sebastian, E-mail: felix.kahlhoefer@desy.de, E-mail: kai.schmidt-hoberg@desy.de, E-mail: sebastian.wild@desy.de

2017-08-01

Dark matter particles interacting via the exchange of very light spin-0 mediators can have large self-interaction rates and obtain their relic abundance from thermal freeze-out. At the same time, these models face strong bounds from direct and indirect probes of dark matter as well as a number of constraints on the properties of the mediator. We investigate whether these constraints can be consistent with having observable effects from dark matter self-interactions in astrophysical systems. For the case of a mediator with purely scalar couplings we point out the highly relevant impact of low-threshold direct detection experiments like CRESST-II, which essentiallymore » rule out the simplest realization of this model. These constraints can be significantly relaxed if the mediator has CP-violating couplings, but then the model faces strong constraints from CMB measurements, which can only be avoided in special regions of parameter space.« less

Was the Universe actually radiation dominated prior to nucleosynthesis?

NASA Astrophysics Data System (ADS)

Giblin, John T.; Kane, Gordon; Nesbit, Eva; Watson, Scott; Zhao, Yue

2017-08-01

Maybe not. String theory approaches to both beyond the Standard Model and inflationary model building generically predict the existence of scalars (moduli) that are light compared to the scale of quantum gravity. These moduli become displaced from their low energy minima in the early Universe and lead to a prolonged matter-dominated epoch prior to big bang nucleosynthesis (BBN). In this paper, we examine whether nonperturbative effects such as parametric resonance or tachyonic instabilities can shorten, or even eliminate, the moduli condensate and matter-dominated epoch. Such effects depend crucially on the strength of the couplings, and we find that unless the moduli become strongly coupled, the matter-dominated epoch is unavoidable. In particular, we find that in string and M-theory compactifications where the lightest moduli are near the TeV scale, a matter-dominated epoch will persist until the time of big bang nucleosynthesis.

Higgs production as a probe of chameleon dark energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brax, Philippe; Burrage, Clare; Davis, Anne-Christine

2010-05-15

In this paper we study various particle physics effects of a light, scalar dark energy field with chameleonlike couplings to matter. We show that a chameleon model with only matter couplings will induce a coupling to photons. In doing so, we derive the first microphysical realization of a chameleonic dark energy model coupled to the electromagnetic field strength. This analysis provides additional motivation for current and near-future tests of axionlike and chameleon particles. We find a new bound on the coupling strength of chameleons in uniformly coupled models. We also study the effect of chameleon fields on Higgs production, whichmore » is relevant for hadron colliders. These are expected to manufacture Higgs particles through weak boson fusion, or associated production with a Z or W{sup {+-}.} We show that, like the Tevatron, the LHC will not be able to rule out or observe chameleons through this mechanism, because gauge invariance of the low energy Lagrangian suppresses the corrections that may arise.« less

A light Z' for the R K puzzle and nonstandard neutrino interactions

DOE PAGES

Datta, Alakabha; Liao, Jiajun; Marfatia, Danny

2017-03-01

We show that the R K puzzle in LHCb data and the discrepancy in the anomalous magnetic moment of the muon can be simultaneously explained if a 10 MeV mass Z' boson couples to the muon but not the electron, and that clear evidence of the nonstandard matter interactions of neutrinos induced by this coupling may be found at DUNE.

Collider study on the loop-induced dark matter mediation

NASA Astrophysics Data System (ADS)

Tsai, Yuhsin

2016-06-01

Collider experiments are one of the most promising ways to constrain Dark Matter (DM) interactions. For DM couplings involving light mediators, especially for the loop-mediated interactions, a meaningful interpretation of the results requires to go beyond effective field theory. In this note we discuss the study of the magnetic dipole interacting DM, focusing on a model with anarchic dark flavor structure. By including the momentum-dependent form factors that mediate the coupling - given by the Dark Penguin - in collider processes, we study bounds from monophoton, diphoton, and non-pointing photon searches at the LHC. We also compare our results to constraints from the direct detection experiments.

Physical chemistry of Nanogap-Enhanced Raman Scattering (NERS)

NASA Astrophysics Data System (ADS)

Suh, Yung Doug; Kim, Hyun Woo

2017-08-01

Plasmonically coupled electromagnetic field localization has generated a variety of new concepts and applications, and this has been one of the hottest topics in nanoscience, materials science, chemistry, physics and engineering and increasingly more important over the last decade. In particular, plasmonically coupled nanostructures with ultra-small gap ( 1-nm or smaller) gap have been of special interest due to their ultra-strong optical properties that can be useful for a variety of signal enhancements such surface-enhanced Raman scattering (SERS) and nanoantenna. These promising nanostructures with extraordinarily strong optical signal, however, have rendered a limited success in widespread use and commercialization largely due to the lack of designing principles, high-yield synthetic strategies with nm-level structural controllability and reproducibility and lack of systematic single-molecule and single-particle level studies. All these are extremely important challenges because even small changes ( 1 nm) of the coupled nanogap structures can significant affect plasmon mode and signal intensity and therefore structural and signal reproducibility and controllability can be in question. The plasmonic nanogap-enhanced Raman scattering (NERS) is defined as the plasmonic nanogap-based Raman signal enhancement within plasmonic nanogap particles with 1 nm gap and a Raman dye positioned inside the gap.

Control of strong light-matter coupling using the capacitance of metamaterial nanocavities

DOE PAGES

Benz, Alexander; Campione, Salvatore; Klem, John Frederick; ...

2015-01-27

Metallic nanocavities with deep subwavelength mode volumes can lead to dramatic changes in the behavior of emitters placed in their vicinity. The resulting collocation and interaction often leads to strong coupling. We present for the first time experimental evidence that the Rabi splitting is directly proportional to the electrostatic capacitance associated with the metallic nanocavity. As a result, the system analyzed consists of different metamaterial geometries with the same resonance wavelength coupled to intersubband transitions in quantum wells.

Chiral Three-Nucleon Interactions in Light Nuclei, Neutron-α Scattering, and Neutron Matter

DOE PAGES

Lynn, J. E.; Tews, I.; Carlson, Joseph Allen; ...

2016-02-09

Here we present quantum Monte Carlo calculations of light nuclei, neutron- scattering, and neutron matter using local two- and three-nucleon (3N) interactions derived from chiral e effective fi eld theory up to next-to-next-to-leading order (N 2LO). The two undetermined 3N low-energy couplings are fi t to the 4He binding energy and, for the first time, to the spin-orbit splitting in the neutron- P-wave phase shifts. Furthermore, we investigate different choices of local 3N-operator structures and find that chiral interactions at N 2LO are able to simultaneously reproduce the properties of A = 3; 4; 5 systems and of neutron matter,more » in contrast to commonly used phenomenological 3N interactions.« less

Chiral Three-Nucleon Interactions in Light Nuclei, Neutron-α Scattering, and Neutron Matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lynn, J. E.; Tews, I.; Carlson, Joseph Allen

Here we present quantum Monte Carlo calculations of light nuclei, neutron- scattering, and neutron matter using local two- and three-nucleon (3N) interactions derived from chiral e effective fi eld theory up to next-to-next-to-leading order (N 2LO). The two undetermined 3N low-energy couplings are fi t to the 4He binding energy and, for the first time, to the spin-orbit splitting in the neutron- P-wave phase shifts. Furthermore, we investigate different choices of local 3N-operator structures and find that chiral interactions at N 2LO are able to simultaneously reproduce the properties of A = 3; 4; 5 systems and of neutron matter,more » in contrast to commonly used phenomenological 3N interactions.« less

Plasmonic Control of Multi-Electron Transfer and C-C Coupling in Visible-Light-Driven CO2 Reduction on Au Nanoparticles.

PubMed

Yu, Sungju; Wilson, Andrew J; Heo, Jaeyoung; Jain, Prashant K

2018-04-11

Artificial photosynthesis relies on the availability of synthetic photocatalysts that can drive CO 2 reduction in the presence of water and light. From the standpoint of solar fuel production, it is desirable that these photocatalysts perform under visible light and produce energy-rich hydrocarbons from CO 2 reduction. However, the multistep nature of CO 2 -to-hydrocarbon conversion poses a significant kinetic bottleneck when compared to CO production and H 2 evolution. Here, we show that plasmonic Au nanoparticle photocatalysts can harvest visible light for multielectron, multiproton reduction of CO 2 to yield C 1 (methane) and C 2 (ethane) hydrocarbons. The light-excitation attributes influence the C 2 and C 1 selectivity. The observed trends in activity and selectivity follow Poisson statistics of electron harvesting. Higher photon energies and flux favor simultaneous harvesting of more than one electron from the photocharged Au nanoparticle catalyst, inducing the C-C coupling required for C 2 production. These findings elucidate the nature of plasmonic photocatalysis, which involves strong light-matter coupling, and set the stage for the controlled chemical bond formation by light excitation.

Shining light on modifications of gravity

NASA Astrophysics Data System (ADS)

Brax, Philippe; Burrage, Clare; Davis, Anne-Christine

2012-10-01

Many modifications of gravity introduce new scalar degrees of freedom, and in such theories matter fields typically couple to an effective metric that depends on both the true metric of spacetime and on the scalar field and its derivatives. Scalar field contributions to the effective metric can be classified as conformal and disformal. Disformal terms introduce gradient couplings between scalar fields and the energy momentum tensor of other matter fields, and cannot be constrained by fifth force experiments because the effects of these terms are trivial around static non-relativistic sources. The use of high-precision, low-energy photon experiments to search for conformally coupled scalar fields, called axion-like particles, is well known. In this article we show that these experiments are also constraining for disformal scalar field theories, and are particularly important because of the difficulty of constraining these couplings with other laboratory experiments.

Light-matter interaction in doped microcavities

NASA Astrophysics Data System (ADS)

Averkiev, N. S.; Glazov, M. M.

2007-07-01

We discuss theoretically the light-matter coupling in a microcavity containing a quantum well with a two-dimensional electron gas. The high density limit where the bound exciton states are absent is considered. The matrix element of an interband optical absorption demonstrates the Mahan singularity [Phys. Rev. B153, 882 (1967); 163, 612 (1967)] due to strong Coulomb effect between the electrons and a photocreated hole. We extend the nonlocal dielectric response theory to calculate the quantum well reflection and transmission coefficients as well as the microcavity transmission spectra. The new eigenmodes of the system are discussed. Their implications for the steady state and time-resolved spectroscopy experiments are analyzed.

Magnetic Light-Matter Interactions in a Photonic Crystal Nanocavity

NASA Astrophysics Data System (ADS)

Burresi, M.; Kampfrath, T.; van Oosten, D.; Prangsma, J. C.; Song, B. S.; Noda, S.; Kuipers, L.

2010-09-01

We study the magnetic coupling between a metal-coated near-field probe and a photonic crystal nanocavity. The resonance of the nanocavity shifts to shorter wavelengths when the ringlike apex of the probe is above an antinode of the magnetic field of the cavity. We show that this can be attributed to a magnetic light-matter interaction and is in fact a manifestation of Lenz’s law at optical frequencies. We use these measurements to determine the magnetic polarizability of the apex of the probe and find good agreement with theory. We discuss how this method could be applied to study the electric and magnetic polarizibilities of nano-objects.

Doppelgänger dark energy: modified gravity with non-universal couplings after GW170817

NASA Astrophysics Data System (ADS)

Amendola, Luca; Bettoni, Dario; Domènech, Guillem; Gomes, Adalto R.

2018-06-01

Gravitational Wave (GW) astronomy severely narrowed down the theoretical space for scalar-tensor theories. We propose a new class of attractor models {for Horndeski action} in which GWs propagate at the speed of light in the nearby universe but not in the past. To do so we derive new solutions to the interacting dark sector in which the ratio of dark energy and dark matter remains constant, which we refer to as doppelgänger dark energy (DDE). We then remove the interaction between dark matter and dark energy by a suitable change of variables. The accelerated expansion that (we) baryons observe is due to a conformal coupling to the dark energy scalar field. We show how in this context it is possible to find a non trivial subset of solutions in which GWs propagate at the speed of light only at low red-shifts. The model is an attractor, thus reaching the limit cT→1 relatively fast. However, the effect of baryons turns out to be non-negligible and severely constrains the form of the Lagrangian. In passing, we found that in the simplest DDE models the no-ghost conditions for perturbations require a non-universal coupling to gravity. In the end, we comment on possible ways to solve the lack of matter domination stage for DDE models.

Solar neutrinos as a probe of dark matter-neutrino interactions

NASA Astrophysics Data System (ADS)

Capozzi, Francesco; Shoemaker, Ian M.; Vecchi, Luca

2017-07-01

Sterile neutrinos at the eV scale have long been studied in the context of anomalies in short baseline neutrino experiments. Their cosmology can be made compatible with our understanding of the early Universe provided the sterile neutrino sector enjoys a nontrivial dynamics with exotic interactions, possibly providing a link to the Dark Matter (DM) puzzle. Interactions between DM and neutrinos have also been proposed to address the long-standing "missing satellites" problem in the field of large scale structure formation. Motivated by these considerations, in this paper we discuss realistic scenarios with light steriles coupled to DM . We point out that within this framework active neutrinos acquire an effective coupling to DM that manifests itself as a new matter potential in the propagation within a medium of asymmetric DM . Assuming that at least a small fraction of asymmetric DM has been captured by the Sun, we show that a sizable region of the parameter space of these scenarios can be probed by solar neutrino experiments, especially in the regime of small couplings and light mediators where all other probes become inefficient. In the latter regime these scenarios behave as familiar 3+1 models in all channels except for solar data, where a Solar Dark MSW effect takes place. Solar Dark MSW is characterized by modifications of the most energetic 8B and CNO neutrinos, whereas the other fluxes remain largely unaffected.

Direct detection of exothermic dark matter with light mediator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geng, Chao-Qiang; Department of Physics, National Tsing Hua University,Hsinchu, Taiwan; Physics Division, National Center for Theoretical Sciences,Hsinchu, Taiwan

2016-08-05

We study the dark matter (DM) direct detection for the models with the effects of the isospin-violating couplings, exothermic scatterings, and/or the lightness of the mediator, proposed to relax the tension between the CDMS-Si signals and null experiments. In the light of the new updates of the LUX and CDMSlite data, we find that many of the previous proposals are now ruled out, including the Ge-phobic exothermic DM model and the Xe-phobic DM one with a light mediator. We also examine the exothermic DM models with a light mediator but without the isospin violation, and we are unable to identifymore » any available parameter space that could simultaneously satisfy all the experiments. The only models that can partially relax the inconsistencies are the Xe-phobic exothermic DM models with or without a light mediator. But even in this case, a large portion of the CDMS-Si regions of interest has been constrained by the LUX and SuperCDMS data.« less

Prospecting for new physics in the Higgs and flavor sectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bishara, Fady

We explore two directions in beyond the standard model physics: dark matter model building and probing new sources of CP violation. In dark matter model building, we consider two scenarios where the stability of dark matter derives from the flavor symmetries of the standard model. The first model contains a flavor singlet dark matter candidate whose couplings to the visible sector are proportional to the flavor breaking parameters. This leads to a metastable dark matter with TeV scale mediators. In the second model, we consider a fully gauged SU(3) 3 flavor model with a flavor triplet dark matter. Consequently, the dark matter multiplet is charged while the standard model fields are neutral under a remnant Z 3 which ensures dark matter stability. We show that a Dirac fermion dark matter with radiative splitting in the multiplet must have a mass in the range [0:5; 5] TeV in order to satisfy all experimental constraints. We then turn our attention to Higgs portal dark matter and investigate the possibility of obtaining bounds on the up, down, and strange quark Yukawa couplings. If Higgs portal dark matter is discovered, we find that direct detection rates are insensitive to vanishing light quark Yukawa couplings. We then review flavor models and give the expected enhancement or suppression of the Yukawa couplings in those models. Finally, in the last two chapters, we develop techniques for probing CP violation in the Higgs coupling to photons and in rare radiative decays of B mesons. While theoretically clean, we find that these methods are not practical with current and planned detectors. However, these techniques can be useful with a dedicated detector (e.g., a gaseous TPC). In the case of radiative B meson decay B 0 → (K* → Kππ) γ, the techniques we develop also allow the extraction of the photon polarization fraction which is sensitive to new physics contributions since, in the standard model, the right(left) handed polarization fraction is of O( Λ QCD=m b) formore » $$\\bar{B}^{0}$$(B 0) meson decays.« less

Search for light gauge bosons of the dark sector at the Mainz Microtron.

PubMed

Merkel, H; Achenbach, P; Ayerbe Gayoso, C; Bernauer, J C; Böhm, R; Bosnar, D; Debenjak, L; Denig, A; Distler, M O; Esser, A; Fonvieille, H; Friščić, I; Middleton, D G; Müller, U; Nungesser, L; Pochodzalla, J; Rohrbeck, M; Sánchez Majos, S; Schlimme, B S; Schoth, M; Sirca, S; Weinriefer, M

2011-06-24

A new exclusion limit for the electromagnetic production of a light U(1) gauge boson γ' decaying to e + e- was determined by the A1 Collaboration at the Mainz Microtron. Such light gauge bosons appear in several extensions of the standard model and are also discussed as candidates for the interaction of dark matter with standard model matter. In electron scattering from a heavy nucleus, the existing limits for a narrow state coupling to e + e- were reduced by nearly an order of magnitude in the range of the lepton pair mass of 210 MeV/c2}

Room temperature current injection polariton light emitting diode with a hybrid microcavity.

PubMed

Lu, Tien-Chang; Chen, Jun-Rong; Lin, Shiang-Chi; Huang, Si-Wei; Wang, Shing-Chung; Yamamoto, Yoshihisa

2011-07-13

The strong light-matter interaction within a semiconductor high-Q microcavity has been used to produce half-matter/half-light quasiparticles, exciton-polaritons. The exciton-polaritons have very small effective mass and controllable energy-momentum dispersion relation. These unique properties of polaritons provide the possibility to investigate the fundamental physics including solid-state cavity quantum electrodynamics, and dynamical Bose-Einstein condensates (BECs). Thus far the polariton BEC has been demonstrated using optical excitation. However, from a practical viewpoint, the current injection polariton devices operating at room temperature would be most desirable. Here we report the first realization of a current injection microcavity GaN exciton-polariton light emitting diode (LED) operating under room temperature. The exciton-polariton emission from the LED at photon energy 3.02 eV under strong coupling condition is confirmed through temperature-dependent and angle-resolved electroluminescence spectra.

Light-Induced Capacitance Tunability in Ferroelectric Crystals.

PubMed

Páez-Margarit, David; Rubio-Marcos, Fernando; Ochoa, Diego A; Del Campo, Adolfo; Fernández, José F; García, José E

2018-06-25

The remote controlling of ferroic properties with light is nowadays a hot and highly appealing topic in materials science. Here, we shed light on some of the unresolved issues surrounding light-matter coupling in ferroelectrics. Our findings show that the capacitance and, consequently, its related intrinsic material property, i.e., the dielectric constant, can be reversibly adjusted through the light power control. High photodielectric performance is exhibited across a wide range of the visible light wavelength because of the wavelength-independence of the phenomenon. We have verified that this counterintuitive behavior can be strongly ascribed to the existence of "locally free charges" at domain wall.

Detecting superlight dark matter with Fermi-degenerate materials

DOE PAGES

Hochberg, Yonit; Pyle, Matt; Zhao, Yue; ...

2016-08-08

We examine in greater detail the recent proposal of using superconductors for detecting dark matter as light as the warm dark matter limit of O(keV). Detection of suc light dark matter is possible if the entire kinetic energy of the dark matter is extracted in the scattering, and if the experiment is sensitive to O(meV) energy depositions. This is the case for Fermi-degenerate materials in which the Fermi velocity exceeds the dark matter velocity dispersion in the Milky Way of ~10 –3. We focus on a concrete experimental proposal using a superconducting target with a transition edge sensor in ordermore » to detect the small energy deposits from the dark matter scatterings. Considering a wide variety of constraints, from dark matter self-interactions to the cosmic microwave background, we show that models consistent with cosmological/astrophysical and terrestrial constraints are observable with such detectors. A wider range of viable models with dark matter mass below an MeV is available if dark matter or mediator properties (such as couplings or masses) differ at BBN epoch or in stellar interiors from those in superconductors. We also show that metal targets pay a strong in-medium suppression for kinetically mixed mediators; this suppression is alleviated with insulating targets.« less

Deterministic photon-emitter coupling in chiral photonic circuits.

PubMed

Söllner, Immo; Mahmoodian, Sahand; Hansen, Sofie Lindskov; Midolo, Leonardo; Javadi, Alisa; Kiršanskė, Gabija; Pregnolato, Tommaso; El-Ella, Haitham; Lee, Eun Hye; Song, Jin Dong; Stobbe, Søren; Lodahl, Peter

2015-09-01

Engineering photon emission and scattering is central to modern photonics applications ranging from light harvesting to quantum-information processing. To this end, nanophotonic waveguides are well suited as they confine photons to a one-dimensional geometry and thereby increase the light-matter interaction. In a regular waveguide, a quantum emitter interacts equally with photons in either of the two propagation directions. This symmetry is violated in nanophotonic structures in which non-transversal local electric-field components imply that photon emission and scattering may become directional. Here we show that the helicity of the optical transition of a quantum emitter determines the direction of single-photon emission in a specially engineered photonic-crystal waveguide. We observe single-photon emission into the waveguide with a directionality that exceeds 90% under conditions in which practically all the emitted photons are coupled to the waveguide. The chiral light-matter interaction enables deterministic and highly directional photon emission for experimentally achievable on-chip non-reciprocal photonic elements. These may serve as key building blocks for single-photon optical diodes, transistors and deterministic quantum gates. Furthermore, chiral photonic circuits allow the dissipative preparation of entangled states of multiple emitters for experimentally achievable parameters, may lead to novel topological photon states and could be applied for directional steering of light.

Deterministic photon-emitter coupling in chiral photonic circuits

NASA Astrophysics Data System (ADS)

Söllner, Immo; Mahmoodian, Sahand; Hansen, Sofie Lindskov; Midolo, Leonardo; Javadi, Alisa; Kiršanskė, Gabija; Pregnolato, Tommaso; El-Ella, Haitham; Lee, Eun Hye; Song, Jin Dong; Stobbe, Søren; Lodahl, Peter

2015-09-01

Engineering photon emission and scattering is central to modern photonics applications ranging from light harvesting to quantum-information processing. To this end, nanophotonic waveguides are well suited as they confine photons to a one-dimensional geometry and thereby increase the light-matter interaction. In a regular waveguide, a quantum emitter interacts equally with photons in either of the two propagation directions. This symmetry is violated in nanophotonic structures in which non-transversal local electric-field components imply that photon emission and scattering may become directional. Here we show that the helicity of the optical transition of a quantum emitter determines the direction of single-photon emission in a specially engineered photonic-crystal waveguide. We observe single-photon emission into the waveguide with a directionality that exceeds 90% under conditions in which practically all the emitted photons are coupled to the waveguide. The chiral light-matter interaction enables deterministic and highly directional photon emission for experimentally achievable on-chip non-reciprocal photonic elements. These may serve as key building blocks for single-photon optical diodes, transistors and deterministic quantum gates. Furthermore, chiral photonic circuits allow the dissipative preparation of entangled states of multiple emitters for experimentally achievable parameters, may lead to novel topological photon states and could be applied for directional steering of light.

Collider study on the loop-induced dark matter mediation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsai, Yuhsin, E-mail: yhtsai@umd.edu

2016-06-21

Collider experiments are one of the most promising ways to constrain Dark Matter (DM) interactions. For DM couplings involving light mediators, especially for the loop-mediated interactions, a meaningful interpretation of the results requires to go beyond effective field theory. In this note we discuss the study of the magnetic dipole interacting DM, focusing on a model with anarchic dark flavor structure. By including the momentum-dependent form factors that mediate the coupling – given by the Dark Penguin – in collider processes, we study bounds from monophoton, diphoton, and non-pointing photon searches at the LHC. We also compare our results tomore » constraints from the direct detection experiments.« less

Emergent causality and the N-photon scattering matrix in waveguide QED

NASA Astrophysics Data System (ADS)

Sánchez-Burillo, E.; Cadarso, A.; Martín-Moreno, L.; García-Ripoll, J. J.; Zueco, D.

2018-01-01

In this work we discuss the emergence of approximate causality in a general setup from waveguide QED—i.e. a one-dimensional propagating field interacting with a scatterer. We prove that this emergent causality translates into a structure for the N-photon scattering matrix. Our work builds on the derivation of a Lieb-Robinson-type bound for continuous models and for all coupling strengths, as well as on several intermediate results, of which we highlight: (i) the asymptotic independence of space-like separated wave packets, (ii) the proper definition of input and output scattering states, and (iii) the characterization of the ground state and correlations in the model. We illustrate our formal results by analyzing the two-photon scattering from a quantum impurity in the ultrastrong coupling regime, verifying the cluster decomposition and ground-state nature. Besides, we generalize the cluster decomposition if inelastic or Raman scattering occurs, finding the structure of the S-matrix in momentum space for linear dispersion relations. In this case, we compute the decay of the fluorescence (photon-photon correlations) caused by this S-matrix.

Augury of darkness: the low-mass dark Z' portal

DOE PAGES

Alves, Alexandre; Arcadi, Giorgio; Mambrini, Yann; ...

2017-04-28

Dirac fermion dark matter models with heavy Z' mediators are subject to stringent constraints from spin-independent direct searches and from LHC bounds, cornering them to live near the Z' resonance. Such constraints can be relaxed, however, by turning off the vector coupling to Standard Model fermions, thus weakening direct detection bounds, or by resorting to light Z' masses, below the Z pole, to escape heavy resonance searches at the LHC. In this work we investigate both cases, as well as the applicability of our findings to Majorana dark matter. We derive collider bounds for light Z' gauge bosons using themore » CL S method, spin-dependent scattering limits, as well as the spin-independent scattering rate arising from the evolution of couplings between the energy scale of the mediator mass and the nuclear energy scale, and indirect detection limits. In conclusion, we show that such scenarios are still rather constrained by data, and that near resonance they could accommodate the gamma-ray GeV excess in the Galactic center.« less

Oxidative and photoxidative polymerization of humic suprastructures by heterogeneous biomimetic catalysis.

PubMed

Nuzzo, Assunta; Piccolo, Alessandro

2013-05-13

The meso-tetra(2,6-dichloro-3-sulfonatophenyl)porphyrinate of manganese(III) chloride [Mn-(TDCPPS)Cl] biomimetic catalyst immobilized on spacer-functionalized kaolinite clay mineral was employed in the oxidative coupling reaction of a dissolved humic acid (HA) suprastructure with either chemical (H2O2) or UV-light oxidation. The changes in molecular size of humic matter subjected to catalyzed oxidative reaction were followed by high-performance size exclusion chromatography (HPSEC) with UV-vis and refractive index (RI) detectors in series, and by thermogravimetric (TGA) analysis. Both the enhanced molecular size shown by differences between HPSEC chromatograms of humic reaction mixtures at either pH 6 or 3.5 and the increase of thermogravimetric stability suggest that the heterogeneous biomimetic catalysis promoted the stabilization of humic conformations by new intermolecular covalent bonds during oxidative coupling. The similarity between chemical and light-induced oxidation results suggests potential multiple applications of the kaolinite-supported heterogeneous catalyst in controlling the reactivity of natural organic matter within biogeochemical cycles and environmental reactions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hochberg, Yonit; Pyle, Matt; Zhao, Yue

We examine in greater detail the recent proposal of using superconductors for detecting dark matter as light as the warm dark matter limit of O(keV). Detection of suc light dark matter is possible if the entire kinetic energy of the dark matter is extracted in the scattering, and if the experiment is sensitive to O(meV) energy depositions. This is the case for Fermi-degenerate materials in which the Fermi velocity exceeds the dark matter velocity dispersion in the Milky Way of ~10 –3. We focus on a concrete experimental proposal using a superconducting target with a transition edge sensor in ordermore » to detect the small energy deposits from the dark matter scatterings. Considering a wide variety of constraints, from dark matter self-interactions to the cosmic microwave background, we show that models consistent with cosmological/astrophysical and terrestrial constraints are observable with such detectors. A wider range of viable models with dark matter mass below an MeV is available if dark matter or mediator properties (such as couplings or masses) differ at BBN epoch or in stellar interiors from those in superconductors. We also show that metal targets pay a strong in-medium suppression for kinetically mixed mediators; this suppression is alleviated with insulating targets.« less

Analyzing the Discovery Potential for Light Dark Matter.

PubMed

Izaguirre, Eder; Krnjaic, Gordan; Schuster, Philip; Toro, Natalia

2015-12-18

In this Letter, we determine the present status of sub-GeV thermal dark matter annihilating through standard model mixing, with special emphasis on interactions through the vector portal. Within representative simple models, we carry out a complete and precise calculation of the dark matter abundance and of all available constraints. We also introduce a concise framework for comparing different experimental approaches, and use this comparison to identify important ranges of dark matter mass and couplings to better explore in future experiments. The requirement that dark matter be a thermal relic sets a sharp sensitivity target for terrestrial experiments, and so we highlight complementary experimental approaches that can decisively reach this milestone sensitivity over the entire sub-GeV mass range.

Solar neutrinos as a probe of dark matter-neutrino interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Capozzi, Francesco; Vecchi, Luca; Shoemaker, Ian M., E-mail: capozzi.12@osu.edu, E-mail: ian.shoemaker@usd.edu, E-mail: vecchi@infn.pd.it

2017-07-01

Sterile neutrinos at the eV scale have long been studied in the context of anomalies in short baseline neutrino experiments. Their cosmology can be made compatible with our understanding of the early Universe provided the sterile neutrino sector enjoys a nontrivial dynamics with exotic interactions, possibly providing a link to the Dark Matter (DM) puzzle. Interactions between DM and neutrinos have also been proposed to address the long-standing 'missing satellites' problem in the field of large scale structure formation. Motivated by these considerations, in this paper we discuss realistic scenarios with light steriles coupled to DM . We point outmore » that within this framework active neutrinos acquire an effective coupling to DM that manifests itself as a new matter potential in the propagation within a medium of asymmetric DM . Assuming that at least a small fraction of asymmetric DM has been captured by the Sun, we show that a sizable region of the parameter space of these scenarios can be probed by solar neutrino experiments, especially in the regime of small couplings and light mediators where all other probes become inefficient. In the latter regime these scenarios behave as familiar 3+1 models in all channels except for solar data, where a Solar Dark MSW effect takes place. Solar Dark MSW is characterized by modifications of the most energetic {sup 8}B and CNO neutrinos, whereas the other fluxes remain largely unaffected.« less

Microstructural imaging of the human brain with a 'super-scanner': 10 key advantages of ultra-strong gradients for diffusion MRI.

PubMed

Jones, D K; Alexander, D C; Bowtell, R; Cercignani, M; Dell'Acqua, F; McHugh, D J; Miller, K L; Palombo, M; Parker, G J M; Rudrapatna, U S; Tax, C M W

2018-05-22

The key component of a microstructural diffusion MRI 'super-scanner' is a dedicated high-strength gradient system that enables stronger diffusion weightings per unit time compared to conventional gradient designs. This can, in turn, drastically shorten the time needed for diffusion encoding, increase the signal-to-noise ratio, and facilitate measurements at shorter diffusion times. This review, written from the perspective of the UK National Facility for In Vivo MR Imaging of Human Tissue Microstructure, an initiative to establish a shared 300 mT/m-gradient facility amongst the microstructural imaging community, describes ten advantages of ultra-strong gradients for microstructural imaging. Specifically, we will discuss how the increase of the accessible measurement space compared to a lower-gradient systems (in terms of Δ, b-value, and TE) can accelerate developments in the areas of 1) axon diameter distribution mapping; 2) microstructural parameter estimation; 3) mapping micro-vs macroscopic anisotropy features with gradient waveforms beyond a single pair of pulsed-gradients; 4) multi-contrast experiments, e.g. diffusion-relaxometry; 5) tractography and high-resolution imaging in vivo and 6) post mortem; 7) diffusion-weighted spectroscopy of metabolites other than water; 8) tumour characterisation; 9) functional diffusion MRI; and 10) quality enhancement of images acquired on lower-gradient systems. We finally discuss practical barriers in the use of ultra-strong gradients, and provide an outlook on the next generation of 'super-scanners'. Copyright © 2018. Published by Elsevier Inc.

DAEδALUS and dark matter detection

DOE PAGES

Kahn, Yonatan; Krnjaic, Gordan; Thaler, Jesse; ...

2015-03-05

Among laboratory probes of dark matter, fixed-target neutrino experiments are particularly well suited to search for light weakly coupled dark sectors. Here in this paper, we show that the DAEδALUS source setup$-$an 800 MeV proton beam impinging on a target of graphite and copper$-$can improve the present LSND bound on dark photon models by an order of magnitude over much of the accessible parameter space for light dark matter when paired with a suitable neutrino detector such as LENA. Interestingly, both DAEδALUS and LSND are sensitive to dark matter produced from off-shell dark photons. We show for the first timemore » that LSND can be competitive with searches for visible dark photon decays and that fixed-target experiments have sensitivity to a much larger range of heavy dark photon masses than previously thought. We review the mechanism for dark matter production and detection through a dark photon mediator, discuss the beam-off and beam-on backgrounds, and present the sensitivity in dark photon kinetic mixing for both the DAEδALUS/LENA setup and LSND in both the on- and off-shell regimes.« less

Spin precession experiments for light axionic dark matter

NASA Astrophysics Data System (ADS)

Graham, Peter W.; Kaplan, David E.; Mardon, Jeremy; Rajendran, Surjeet; Terrano, William A.; Trahms, Lutz; Wilkason, Thomas

2018-03-01

Axionlike particles are promising candidates to make up the dark matter of the Universe, but it is challenging to design experiments that can detect them over their entire allowed mass range. Dark matter in general, and, in particular, axionlike particles and hidden photons, can be as light as roughly 10-22 eV (˜10-8 Hz ), with astrophysical anomalies providing motivation for the lightest masses ("fuzzy dark matter"). We propose experimental techniques for direct detection of axionlike dark matter in the mass range from roughly 10-13 eV (˜102 Hz ) down to the lowest possible masses. In this range, these axionlike particles act as a time-oscillating magnetic field coupling only to spin, inducing effects such as a time-oscillating torque and periodic variations in the spin-precession frequency with the frequency and direction of these effects set by the axion field. We describe how these signals can be measured using existing experimental technology, including torsion pendulums, atomic magnetometers, and atom interferometry. These experiments demonstrate a strong discovery capability, with future iterations of these experiments capable of pushing several orders of magnitude past current astrophysical bounds.

Supermode-density-wave-polariton condensation with a Bose–Einstein condensate in a multimode cavity

PubMed Central

Kollár, Alicia J.; Papageorge, Alexander T.; Vaidya, Varun D.; Guo, Yudan; Keeling, Jonathan; Lev, Benjamin L.

2017-01-01

Phase transitions, where observable properties of a many-body system change discontinuously, can occur in both open and closed systems. By placing cold atoms in optical cavities and inducing strong coupling between light and excitations of the atoms, one can experimentally study phase transitions of open quantum systems. Here we observe and study a non-equilibrium phase transition, the condensation of supermode-density-wave polaritons. These polaritons are formed from a superposition of cavity photon eigenmodes (a supermode), coupled to atomic density waves of a quantum gas. As the cavity supports multiple photon spatial modes and because the light–matter coupling can be comparable to the energy splitting of these modes, the composition of the supermode polariton is changed by the light–matter coupling on condensation. By demonstrating the ability to observe and understand density-wave-polariton condensation in the few-mode-degenerate cavity regime, our results show the potential to study similar questions in fully multimode cavities. PMID:28211455

On-chip synthesis of circularly polarized emission of light with integrated photonic circuits.

PubMed

He, Li; Li, Mo

2014-05-01

The helicity of circularly polarized (CP) light plays an important role in the light-matter interaction in magnetic and quantum material systems. Exploiting CP light in integrated photonic circuits could lead to on-chip integration of novel optical helicity-dependent devices for applications ranging from spintronics to quantum optics. In this Letter, we demonstrate a silicon photonic circuit coupled with a 2D grating emitter operating at a telecom wavelength to synthesize vertically emitting, CP light from a quasi-TE waveguide mode. Handedness of the emitted circular polarized light can be thermally controlled with an integrated microheater. The compact device footprint enables a small beam diameter, which is desirable for large-scale integration.

Characterization of Strong Light-Matter Coupling in Semiconductor Quantum-Dot Microcavities via Photon-Statistics Spectroscopy

NASA Astrophysics Data System (ADS)

Schneebeli, L.; Kira, M.; Koch, S. W.

2008-08-01

It is shown that spectrally resolved photon-statistics measurements of the resonance fluorescence from realistic semiconductor quantum-dot systems allow for high contrast identification of the two-photon strong-coupling states. Using a microscopic theory, the second-rung resonance of Jaynes-Cummings ladder is analyzed and optimum excitation conditions are determined. The computed photon-statistics spectrum displays gigantic, experimentally robust resonances at the energetic positions of the second-rung emission.

Mechanic-Like Resonance in the Maxwell-Bloch Equations

ERIC Educational Resources Information Center

Meziane, Belkacem

2008-01-01

We show that, in their unstable regime of operation, the "Maxwell-Bloch" equations that describe light-matter interactions inside a bad-cavity-configured laser carry the same resonance properties as any externally driven mechanic or electric oscillator. This finding demonstrates that the nonlinearly coupled laser equations belong to the same…

Correlated Light-Matter Interactions in Cavity QED

NASA Astrophysics Data System (ADS)

Flick, Johannes; Pellegrini, Camilla; Ruggenthaler, Michael; Appel, Heiko; Tokatly, Ilya; Rubio, Angel

2015-03-01

In the last decade, time-dependent density functional theory (TDDFT) has been successfully applied to a large variety of problems, such as calculations of absorption spectra, excitation energies, or dynamics in strong laser fields. Recently, we have generalized TDDFT to also describe electron-photon systems (QED-TDDFT). Here, matter and light are treated on an equal quantized footing. In this work, we present the first numerical calculations in the framework of QED-TDDFT. We show exact solutions for fully quantized prototype systems consisting of atoms or molecules placed in optical high-Q cavities and coupled to quantized electromagnetic modes. We focus on the electron-photon exchange-correlation (xc) contribution by calculating exact Kohn-Sham potentials using fixed-point inversions and present the performance of the first approximated xc-potential based on an optimized effective potential (OEP) approach. Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, and Fritz-Haber-Institut der MPG, Berlin

Minimal model linking two great mysteries: Neutrino mass and dark matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farzan, Yasaman

2009-10-01

We present an economic model that establishes a link between neutrino masses and properties of the dark matter candidate. The particle content of the model can be divided into two groups: light particles with masses lighter than the electroweak scale and heavy particles. The light particles, which also include the dark matter candidate, are predicted to show up in the low energy experiments such as (K{yields}l+missing energy), making the model testable. The heavy sector can show up at the LHC and may give rise to Br(l{sub i}{yields}l{sub j}{gamma}) close to the present bounds. In principle, the new couplings of themore » model can independently be derived from the data from the LHC and from the information on neutrino masses and lepton flavor violating rare decays, providing the possibility of an intensive cross-check of the model.« less

Magnon dark modes and gradient memory

PubMed Central

Zhang, Xufeng; Zou, Chang-Ling; Zhu, Na; Marquardt, Florian; Jiang, Liang; Tang, Hong X.

2015-01-01

Extensive efforts have been expended in developing hybrid quantum systems to overcome the short coherence time of superconducting circuits by introducing the naturally long-lived spin degree of freedom. Among all the possible materials, single-crystal yttrium iron garnet has shown up recently as a promising candidate for hybrid systems, and various highly coherent interactions, including strong and even ultrastrong coupling, have been demonstrated. One distinct advantage in these systems is that spins form well-defined magnon modes, which allows flexible and precise tuning. Here we demonstrate that by dissipation engineering, a non-Markovian interaction dynamics between the magnon and the microwave cavity photon can be achieved. Such a process enables us to build a magnon gradient memory to store information in the magnon dark modes, which decouple from the microwave cavity and thus preserve a long lifetime. Our findings provide a promising approach for developing long-lifetime, multimode quantum memories. PMID:26568130

Shaping metallic glasses by electromagnetic pulsing

PubMed Central

Kaltenboeck, Georg; Demetriou, Marios D.; Roberts, Scott; Johnson, William L.

2016-01-01

With damage tolerance rivalling advanced engineering alloys and thermoplastic forming capabilities analogous to conventional plastics, metallic glasses are emerging as a modern engineering material. Here, we take advantage of their unique electrical and rheological properties along with the classic Lorentz force concept to demonstrate that electromagnetic coupling of electric current and a magnetic field can thermoplastically shape a metallic glass without conventional heating sources or applied mechanical forces. Specifically, we identify a process window where application of an electric current pulse in the presence of a normally directed magnetic field can ohmically heat a metallic glass to a softened state, while simultaneously inducing a large enough magnetic body force to plastically shape it. The heating and shaping is performed on millisecond timescales, effectively bypassing crystallization producing fully amorphous-shaped parts. This electromagnetic forming approach lays the groundwork for a versatile, time- and energy-efficient manufacturing platform for ultrastrong metals. PMID:26853460

Magnon dark modes and gradient memory.

PubMed

Zhang, Xufeng; Zou, Chang-Ling; Zhu, Na; Marquardt, Florian; Jiang, Liang; Tang, Hong X

2015-11-16

Extensive efforts have been expended in developing hybrid quantum systems to overcome the short coherence time of superconducting circuits by introducing the naturally long-lived spin degree of freedom. Among all the possible materials, single-crystal yttrium iron garnet has shown up recently as a promising candidate for hybrid systems, and various highly coherent interactions, including strong and even ultrastrong coupling, have been demonstrated. One distinct advantage in these systems is that spins form well-defined magnon modes, which allows flexible and precise tuning. Here we demonstrate that by dissipation engineering, a non-Markovian interaction dynamics between the magnon and the microwave cavity photon can be achieved. Such a process enables us to build a magnon gradient memory to store information in the magnon dark modes, which decouple from the microwave cavity and thus preserve a long lifetime. Our findings provide a promising approach for developing long-lifetime, multimode quantum memories.

Superradiance and dynamical instability in an illuminated BEC

NASA Astrophysics Data System (ADS)

Lunden, William; Amato-Grill, Jesse; Dimitrova, Ivana; Jepsen, Niklas; Ketterle, Wolfgang

2017-04-01

An elongated, trapped Bose-Einstein condensate illuminated by an off-resonant laser beam has been used as a platform to observe superradiant Rayleigh scattering for almost two decades. We now consider the case of an elongated BEC illuminated by a pair of non-interfering, off-resonant lasers, and explore the dynamics of the coupled light-matter system in the short-time regime (i.e., times on the order of the inverse of the single-photon recoil frequency). In particular, we look for signatures of a proposed dynamical instability in the coupled system which spontaneously breaks the translational symmetry of both the BEC density and the total light field's intensity profile along the long axis of the trap. We also explore the relative roles of the spontaneous light force and the dipole force in both superradiance and this dynamical instability.

Quantum state engineering in hybrid open quantum systems

NASA Astrophysics Data System (ADS)

Joshi, Chaitanya; Larson, Jonas; Spiller, Timothy P.

2016-04-01

We investigate a possibility to generate nonclassical states in light-matter coupled noisy quantum systems, namely, the anisotropic Rabi and Dicke models. In these hybrid quantum systems, a competing influence of coherent internal dynamics and environment-induced dissipation drives the system into nonequilibrium steady states (NESSs). Explicitly, for the anisotropic Rabi model, the steady state is given by an incoherent mixture of two states of opposite parities, but as each parity state displays light-matter entanglement, we also find that the full state is entangled. Furthermore, as a natural extension of the anisotropic Rabi model to an infinite spin subsystem, we next explored the NESS of the anisotropic Dicke model. The NESS of this linearized Dicke model is also an inseparable state of light and matter. With an aim to enrich the dynamics beyond the sustainable entanglement found for the NESS of these hybrid quantum systems, we also propose to combine an all-optical feedback strategy for quantum state protection and for establishing quantum control in these systems. Our present work further elucidates the relevance of such hybrid open quantum systems for potential applications in quantum architectures.

Supersymmetric leptogenesis with a light hidden sector

NASA Astrophysics Data System (ADS)

De Simone, Andrea; Garny, Mathias; Ibarra, Alejandro; Weniger, Christoph

2010-07-01

Supersymmetric scenarios incorporating thermal leptogenesis as the origin of the observed matter-antimatter asymmetry generically predict abundances of the primordial elements which are in conflict with observations. In this paper we propose a simple way to circumvent this tension and accommodate naturally thermal leptogenesis and primordial nucleosynthesis. We postulate the existence of a light hidden sector, coupled very weakly to the Minimal Supersymmetric Standard Model, which opens up new decay channels for the next-to-lightest supersymmetric particle, thus diluting its abundance during nucleosynthesis. We present a general model-independent analysis of this mechanism as well as two concrete realizations, and describe the relevant cosmological and astrophysical bounds and implications for this dark matter scenario. Possible experimental signatures at colliders and in cosmic-ray observations are also discussed.

Tunable ion-photon entanglement in an optical cavity.

PubMed

Stute, A; Casabone, B; Schindler, P; Monz, T; Schmidt, P O; Brandstätter, B; Northup, T E; Blatt, R

2012-05-23

Proposed quantum networks require both a quantum interface between light and matter and the coherent control of quantum states. A quantum interface can be realized by entangling the state of a single photon with the state of an atomic or solid-state quantum memory, as demonstrated in recent experiments with trapped ions, neutral atoms, atomic ensembles and nitrogen-vacancy spins. The entangling interaction couples an initial quantum memory state to two possible light-matter states, and the atomic level structure of the memory determines the available coupling paths. In previous work, the transition parameters of these paths determined the phase and amplitude of the final entangled state, unless the memory was initially prepared in a superposition state (a step that requires coherent control). Here we report fully tunable entanglement between a single (40)Ca(+) ion and the polarization state of a single photon within an optical resonator. Our method, based on a bichromatic, cavity-mediated Raman transition, allows us to select two coupling paths and adjust their relative phase and amplitude. The cavity setting enables intrinsically deterministic, high-fidelity generation of any two-qubit entangled state. This approach is applicable to a broad range of candidate systems and thus is a promising method for distributing information within quantum networks.

An Accretion Model for Anomalous X-Ray Pulsars

NASA Astrophysics Data System (ADS)

Chatterjee, Pinaki; Hernquist, Lars; Narayan, Ramesh

2000-05-01

We present a model for the anomalous X-ray pulsars (AXPs) in which the emission is powered by accretion from a fossil disk, established from matter falling back onto the neutron star following its birth. The time-dependent accretion drives the neutron star toward a ``tracking'' solution in which the rotation period of the star increases slowly, in tandem with the declining accretion rate. For appropriate choices of disk mass, neutron star magnetic field strength, and initial spin period, we demonstrate that a rapidly rotating neutron star can be spun down to periods characteristic of AXPs on timescales comparable to the estimated ages of these sources. In other cases, accretion onto the neutron star switches off after a short time and the star becomes an ordinary radio pulsar. Thus, in our picture, radio pulsars and AXPs are drawn from the same underlying population, in contrast to the situation in models involving neutron stars with ultrastrong magnetic fields, which require a new population of stars with very different properties.

Asymmetric thermal-relic dark matter: Sommerfeld-enhanced freeze-out, annihilation signals and unitarity bounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baldes, Iason; Petraki, Kalliopi, E-mail: iason.baldes@desy.de, E-mail: kpetraki@lpthe.jussieu.fr

Dark matter that possesses a particle-antiparticle asymmetry and has thermalised in the early universe, requires a larger annihilation cross-section compared to symmetric dark matter, in order to deplete the dark antiparticles and account for the observed dark matter density. The annihilation cross-section determines the residual symmetric component of dark matter, which may give rise to annihilation signals during CMB and inside haloes today. We consider dark matter with long-range interactions, in particular dark matter coupled to a light vector or scalar force mediator. We compute the couplings required to attain a final antiparticle-to-particle ratio after the thermal freeze-out of themore » annihilation processes in the early universe, and then estimate the late-time annihilation signals. We show that, due to the Sommerfeld enhancement, highly asymmetric dark matter with long-range interactions can have a significant annihilation rate, potentially larger than symmetric dark matter of the same mass with contact interactions. We discuss caveats in this estimation, relating to the formation of stable bound states. Finally, we consider the non-relativistic partial-wave unitarity bound on the inelastic cross-section, we discuss why it can be realised only by long-range interactions, and showcase the importance of higher partial waves in this regime of large inelasticity. We derive upper bounds on the mass of symmetric and asymmetric thermal-relic dark matter for s -wave and p -wave annihilation, and exhibit how these bounds strengthen as the dark asymmetry increases.« less

Split Dirac Supersymmetry: An Ultraviolet Completion of Higgsino Dark Matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fox, Patrick J.; Kribs, Graham D.; Martin, Adam

2014-10-07

Motivated by the observation that the Higgs quartic coupling runs to zero at an intermediate scale, we propose a new framework for models of split supersymmetry, in which gauginos acquire intermediate scale Dirac masses ofmore » $$\\sim 10^{8-11}$$ GeV. Scalar masses arise from one-loop finite contributions as well as direct gravity-mediated contributions. Like split supersymmetry, one Higgs doublet is fine-tuned to be light. The scale at which the Dirac gauginos are introduced to make the Higgs quartic zero is the same as is necessary for gauge coupling unification. Thus, gauge coupling unification persists (nontrivially, due to adjoint multiplets), though with a somewhat higher unification scale $$\\gtrsim 10^{17}$$ GeV. The $$\\mu$$-term is naturally at the weak scale, and provides an opportunity for experimental verification. We present two manifestations of Split Dirac Supersymmetry. In the "Pure Dirac" model, the lightest Higgsino must decay through R-parity violating couplings, leading to an array of interesting signals in colliders. In the "Hypercharge Impure" model, the bino acquires a Majorana mass that is one-loop suppressed compared with the Dirac gluino and wino. This leads to weak scale Higgsino dark matter whose overall mass scale, as well as the mass splitting between the neutral components, is naturally generated from the same UV dynamics. We outline the challenges to discovering pseudo-Dirac Higgsino dark matter in collider and dark matter detection experiments.« less

Hybrid Light-Matter States in a Molecular and Material Science Perspective.

PubMed

Ebbesen, Thomas W

2016-11-15

The notion that light and matter states can be hybridized the way s and p orbitals are mixed is a concept that is not familiar to most chemists and material scientists. Yet it has much potential for molecular and material sciences that is just beginning to be explored. For instance, it has already been demonstrated that the rate and yield of chemical reactions can be modified and that the conductivity of organic semiconductors and nonradiative energy transfer can be enhanced through the hybridization of electronic transitions. The hybridization is not limited to electronic transitions; it can be applied for instance to vibrational transitions to selectively perturb a given bond, opening new possibilities to change the chemical reactivity landscape and to use it as a tool in (bio)molecular science and spectroscopy. Such results are not only the consequence of the new eigenstates and energies generated by the hybridization. The hybrid light-matter states also have unusual properties: they can be delocalized over a very large number of molecules (up to ca. 10 5 ), and they become dispersive or momentum-sensitive. Importantly, the hybridization occurs even in the absence of light because it is the zero-point energies of the molecular and optical transitions that generate the new light-matter states. The present work is not a review but rather an Account from the author's point of view that first introduces the reader to the underlying concepts and details of the features of hybrid light-matter states. It is shown that light-matter hybridization is quite easy to achieve: all that is needed is to place molecules or a material in a resonant optical cavity (e.g., between two parallel mirrors) under the right conditions. For vibrational strong coupling, microfluidic IR cells can be used to study the consequences for chemistry in the liquid phase. Examples of modified properties are given to demonstrate the full potential for the molecular and material sciences. Finally an outlook of future directions for this emerging subject is given.

Adding Spice to Vanilla LCDM simulations: Alternative Cosmologies & Lighting up Simulations

NASA Astrophysics Data System (ADS)

Jahan Elahi, Pascal

2015-08-01

Cold Dark Matter simulations have formed the backbone of our theoretical understanding of cosmological structure formation. Predictions from the Lambda Cold Dark Matter (LCDM) cosmology, where the Universe contains two dark components, namely Dark Matter & Dark Energy, are in excellent agreement with the Large-Scale Structures observed, i.e., the distribution of galaxies across cosmic time. However, this paradigm is in tension with observations at small-scales, from the number and properties of satellite galaxies around galaxies such as the Milky Way and Andromeda, to the lensing statistics of massive galaxy clusters. I will present several alternative models of cosmology (from Warm Dark Matter to coupled Dark Matter-Dark Energy models) and how they compare to vanilla LCDM by studying formation of groups and clusters dark matter only and adiabatic hydrodynamical zoom simulations. I will show how modifications to the dark sector can lead to some surprising results. For example, Warm Dark Matter, so often examined on small satellite galaxies scales, can be probed observationally using weak lensing at cluster scales. Coupled dark sectors, where dark matter decays into dark energy and experiences an effective gravitational potential that differs from that experienced by normal matter, is effectively hidden away from direct observations of galaxies. Studies like these are vital if we are to pinpoint observations which can look for unique signatures of the physics that governs the hidden Universe. Finally, I will discuss how all of these predictions are affected by uncertain galaxy formation physics. I will present results from a major comparison study of numerous hydrodynamical codes, the nIFTY cluster comparison project. This comparison aims to understand the code-to-code scatter in the properties of dark matter haloes and the galaxies that reside in them. We find that even in purely adiabatic simulations, different codes form clusters with very different X-ray profiles. The galaxies that form in these simulations, which all use codes that attempt to reproduce the observed galaxy population via not unreasonable subgrid physics, vary in stellar mass, morphology and gas fraction, sometimes by an order of magnitude. I will end with a discussion of precision cosmology in light of these results.

Strong coupling and stimulated emission in single parabolic quantum well microcavity for terahertz cascade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tzimis, A.; Savvidis, P. G.; Institute of Electronic Structure and Laser, Foundation for Research and Technology - Hellas, 71110 Heraklion, Crete

2015-09-07

We report observation of strong light-matter coupling in an AlGaAs microcavity (MC) with an embedded single parabolic quantum well. The parabolic potential is achieved by varying aluminum concentration along the growth direction providing equally spaced energy levels, as confirmed by Brewster angle reflectivity from a reference sample without MC. It acts as an active region of the structure which potentially allows cascaded emission of terahertz (THz) light. Spectrally and time resolved pump-probe spectroscopy reveals characteristic quantum beats whose frequencies range from 0.9 to 4.5 THz, corresponding to energy separation between relevant excitonic levels. The structure exhibits strong stimulated nonlinear emissionmore » with simultaneous transition to weak coupling regime. The present study highlights the potential of such devices for creating cascaded relaxation of bosons, which could be utilized for THz emission.« less

A strongly interacting polaritonic quantum dot

NASA Astrophysics Data System (ADS)

Jia, Ningyuan; Schine, Nathan; Georgakopoulos, Alexandros; Ryou, Albert; Clark, Logan W.; Sommer, Ariel; Simon, Jonathan

2018-06-01

Polaritons are promising constituents of both synthetic quantum matter1 and quantum information processors2, whose properties emerge from their components: from light, polaritons draw fast dynamics and ease of transport; from matter, they inherit the ability to collide with one another. Cavity polaritons are particularly promising as they may be confined and subjected to synthetic magnetic fields controlled by cavity geometry3, and furthermore they benefit from increased robustness due to the cavity enhancement in light-matter coupling. Nonetheless, until now, cavity polaritons have operated only in a weakly interacting mean-field regime4,5. Here we demonstrate strong interactions between individual cavity polaritons enabled by employing highly excited Rydberg atoms as the matter component of the polaritons. We assemble a quantum dot composed of approximately 150 strongly interacting Rydberg-dressed 87Rb atoms in a cavity, and observe blockaded transport of photons through it. We further observe coherent photon tunnelling oscillations, demonstrating that the dot is zero-dimensional. This work establishes the cavity Rydberg polariton as a candidate qubit in a photonic information processor and, by employing multiple resonator modes as the spatial degrees of freedom of a photonic particle, the primary ingredient to form photonic quantum matter6.

Top-philic dark matter within and beyond the WIMP paradigm

NASA Astrophysics Data System (ADS)

Garny, Mathias; Heisig, Jan; Hufnagel, Marco; Lülf, Benedikt

2018-04-01

We present a comprehensive analysis of top-philic Majorana dark matter that interacts via a colored t -channel mediator. Despite the simplicity of the model—introducing three parameters only—it provides an extremely rich phenomenology allowing us to accommodate the relic density for a large range of coupling strengths spanning over 6 orders of magnitude. This model features all "exceptional" mechanisms for dark matter freeze-out, including the recently discovered conversion-driven freeze-out mode, with interesting signatures of long-lived colored particles at colliders. We constrain the cosmologically allowed parameter space with current experimental limits from direct, indirect and collider searches, with special emphasis on light dark matter below the top mass. In particular, we explore the interplay between limits from Xenon1T, Fermi-LAT and AMS-02 as well as limits from stop, monojet and Higgs invisible decay searches at the LHC. We find that several blind spots for light dark matter evade current constraints. The region in parameter space where the relic density is set by the mechanism of conversion-driven freeze-out can be conclusively tested by R -hadron searches at the LHC with 300 fb-1 .

Fluorescence enhancement and strong-coupling in faceted plasmonic nanocavities

NASA Astrophysics Data System (ADS)

Kongsuwan, Nuttawut; Demetriadou, Angela; Chikkaraddy, Rohit; Baumberg, Jeremy J.; Hess, Ortwin

2018-06-01

Emission properties of a quantum emitter can be significantly modified inside nanometre-sized gaps between two plasmonic nanostructures. This forms a nanoscopic optical cavity which allows single-molecule detection and single-molecule strong-coupling at room temperature. However, plasmonic resonances of a plasmonic nanocavity are highly sensitive to the exact gap morphology. In this article, we shed light on the effect of gap morphology on the plasmonic resonances of a faceted nanoparticle-on-mirror (NPoM) nanocavity and their interaction with quantum emitters. We find that with increasing facet width the NPoM nanocavity provides weaker field enhancement and thus less coupling strength to a single quantum emitter since the effective mode volume increases with the facet width. However, if multiple emitters are present, a faceted NPoM nanocavity is capable of accommodating a larger number of emitters, and hence the overall coupling strength is larger due to the collective and coherent energy exchange from all the emitters. Our findings pave the way to more efficient designs of nanocavities for room-temperature light-matter strong-coupling, thus providing a big step forward to a non-cryogenic platform for quantum technologies.

Photonic Architectures for Equilibrium High-Temperature Bose-Einstein Condensation in Dichalcogenide Monolayers

PubMed Central

Jiang, Jian-Hua; John, Sajeev

2014-01-01

Semiconductor-microcavity polaritons are composite quasiparticles of excitons and photons, emerging in the strong coupling regime. As quantum superpositions of matter and light, polaritons have much stronger interparticle interactions compared with photons, enabling rapid equilibration and Bose-Einstein condensation (BEC). Current realizations based on 1D photonic structures, such as Fabry-Pérot microcavities, have limited light-trapping ability resulting in picosecond polariton lifetime. We demonstrate, theoretically, above-room-temperature (up to 590 K) BEC of long-lived polaritons in MoSe2 monolayers sandwiched by simple TiO2 based 3D photonic band gap (PBG) materials. The 3D PBG induces very strong coupling of 40 meV (Rabi splitting of 62 meV) for as few as three dichalcogenide monolayers. Strong light-trapping in the 3D PBG enables the long-lived polariton superfluid to be robust against fabrication-induced disorder and exciton line-broadening. PMID:25503586

Dark matter as a weakly coupled dark baryon

NASA Astrophysics Data System (ADS)

Mitridate, Andrea; Redi, Michele; Smirnov, Juri; Strumia, Alessandro

2017-10-01

Dark Matter might be an accidentally stable baryon of a new confining gauge interaction. We extend previous studies exploring the possibility that the DM is made of dark quarks heavier than the dark confinement scale. The resulting phenomenology contains new unusual elements: a two-stage DM cosmology (freeze-out followed by dark condensation), a large DM annihilation cross section through recombination of dark quarks (allowing to fit the positron excess). Light dark glue-balls are relatively long lived and give extra cosmological effects; DM itself can remain radioactive.

Multipartite interacting scalar dark matter in the light of updated LUX data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhattacharya, Subhaditya; Ghosh, Purusottam; Poulose, Poulose, E-mail: subhab@iitg.ernet.in, E-mail: p.ghosh@iitg.ernet.in, E-mail: poulose@iitg.ernet.in

2017-04-01

We explore constraints on multipartite dark matter (DM) framework composed of singlet scalar DM interacting with the Standard Model (SM) through Higgs portal coupling. We compute relic density and direct search constraints including the updated LUX bound for two component scenario with non-zero interactions between two DM components in Z{sub 2} × Z{sub 2}{sup '} framework in comparison with the one having O(2) symmetry. We point out availability of a significantly large region of parameter space of such a multipartite model with DM-DM interactions.

New limit on possible long-range parity-odd interactions of the neutron from neutron-spin rotation in liquid 4He.

PubMed

Yan, H; Snow, W M

2013-02-22

Various theories beyond the standard model predict new particles with masses in the sub-eV range with very weak couplings to ordinary matter. A parity-odd interaction between polarized nucleons and unpolarized matter proportional to g(V)g(A)s · p is one such possibility, where s[over →] and p[over →] are the spin and the momentum of the polarized nucleon, and g(V) and g(A) are the vector and axial vector couplings of an interaction induced by the exchange of a new light vector boson. We report a new experimental upper bound on such possible long-range parity-odd interactions of the neutron with nucleons and electrons from a recent search for parity violation in neutron spin rotation in liquid ^{4}He. Our constraint on the product of vector and axial vector couplings of a possible new light vector boson is g(V) g(A)(n) ≤ 10(-32) for an interaction range of 1 m. This upper bound is more than 7 orders of magnitude more stringent than the existing laboratory constraints for interaction ranges below 1 m, corresponding to a broad range of vector boson masses above 10(-6) eV. More sensitive searches for a g(V) g(A)(n) coupling could be performed using neutron spin rotation measurements in heavy nuclei or through analysis of experiments conducted to search for nucleon-nucleon weak interactions and nuclear anapole moments.

The ALP miracle: unified inflaton and dark matter

NASA Astrophysics Data System (ADS)

Daido, Ryuji; Takahashi, Fuminobu; Yin, Wen

2017-05-01

We propose a scenario where both inflation and dark matter are described by a single axion-like particle (ALP) in a unified manner. In a class of the minimal axion hilltop inflation, the effective masses at the maximum and mimimum of the potential have equal magnitude but opposite sign, so that the ALP inflaton is light both during inflation and in the true vacuum. After inflation, most of the ALPs decay and evaporate into plasma through a coupling to photons, and the remaining ones become dark matter. We find that the observed CMB and matter power spectrum as well as the dark matter abundance point to an ALP of mass mphi = Script O(0.01) eV and the axion-photon coupling gphi γ γ = Script O(10-11) GeV-1: the ALP miracle. The suggested parameter region is within the reach of the next generation axion helioscope, IAXO, and high-intensity laser experiments in the future. Furthermore, thermalized ALPs contribute to hot dark matter and its abundance is given in terms of the effective number of extra neutrino species, Δ Neff simeq 0.03, which can be tested by the future CMB and BAO observations. We also discuss a case with multiple ALPs, where the coupling to photons can be enhanced in the early Universe by an order of magnitude or more, which enlarges the parameter space for the ALP miracle. The heavy ALP plays a role of the waterfall field in hybrid inflation, and reheats the Universe, and it can be searched for in various experiments such as SHiP.

Strongly self-interacting vector dark matter via freeze-in

NASA Astrophysics Data System (ADS)

Duch, Mateusz; Grzadkowski, Bohdan; Huang, Da

2018-01-01

We study a vector dark matter (VDM) model in which the dark sector couples to the Standard Model sector via a Higgs portal. If the portal coupling is small enough the VDM can be produced via the freeze-in mechanism. It turns out that the electroweak phase transition have a substantial impact on the prediction of the VDM relic density. We further assume that the dark Higgs boson which gives the VDM mass is so light that it can induce strong VDM self-interactions and solve the small-scale structure problems of the Universe. As illustrated by the latest LUX data, the extreme smallness of the Higgs portal coupling required by the freeze-in mechanism implies that the dark matter direct detection bounds are easily satisfied. However, the model is well constrained by the indirect detections of VDM from BBN, CMB, AMS-02, and diffuse γ/X-rays. Consequently, only when the dark Higgs boson mass is at most of O (keV) does there exist a parameter region which leads to a right amount of VDM relic abundance and an appropriate VDM self-scattering while satisfying all other constraints simultaneously.

Direct detection with dark mediators

DOE PAGES

Curtin, David; Surujon, Ze'ev; Tsai, Yuhsin

2014-10-16

We introduce dark mediator Dark Matter (dmDM) where the dark and visible sectors are connected by at least one light mediator Φ carrying the same dark charge that stabilizes DM. Φ is coupled to the Standard Model via an operator q¯qΦΦ*/Λ, and to dark matter via a Yukawa coupling y χX¯ cXΦ. Direct detection is realized as the 2 → 3 process χN → χ¯NΦ at tree-level for m Φ≲10 keV and small Yukawa coupling, or alternatively as a loop-induced 2 → 2 process χN → χN. We explore the direct-detection consequences of this scenario and find that a heavymore » O(100 GeV) dmDM candidate fakes different O(10 GeV) standard WIMPs in different experiments. Large portions of the dmDM parameter space are detectable above the irreducible neutrino background and not yet excluded by any bounds. Interestingly, for the m Φ range leading to novel direct detection phenomenology, dmDM is also a form of Self-Interacting Dark Matter (SIDM), which resolves inconsistencies between dwarf galaxy observations and numerical simulations.« less

Dark-matter QCD-axion searches

DOE PAGES

Rosenberg, Leslie J.

2015-01-12

In the late 20th century, cosmology became a precision science. At the beginning of the next century, the parameters describing how our universe evolved from the Big Bang are generally known to a few percent. One key parameter is the total mass density of the universe. Normal matter constitutes only a small fraction of the total mass density. Observations suggest this additional mass, the dark matter, is cold (that is, moving nonrelativistically in the early universe) and interacts feebly if at all with normal matter and radiation. There’s no known such elementary particle, so the strong presumption is the darkmore » matter consists of particle relics of a new kind left over from the Big Bang. One of the most important questions in science is the nature of this dark matter. One attractive particle dark-matter candidate is the axion. The axion is a hypothetical elementary particle arising in a simple and elegant extension to the standard model of particle physics that nulls otherwise observable CP-violating effects (where CP is the product of charge reversal C and parity inversion P) in quantum chromo dynamics (QCD). A light axion of mass 10 -(6–3) eV (the invisible axion) would couple extraordinarily weakly to normal matter and radiation and would therefore be extremely difficult to detect in the laboratory. But, such an axion is a compelling dark-matter candidate and is therefore a target of a number of searches. Compared with other particle dark-matter candidates, the plausible range of axion dark-matter couplings and masses is narrowly constrained. This focused search range allows for definitive searches, where a nonobservation would seriously impugn the dark-matter QCD-axion hypothesis. Axion searches use a wide range of technologies, and the experiment sensitivities are now reaching likely dark-matter axion couplings and masses. Our paper is a selective overview of the current generation of sensitive axion searches. Finally, not all techniques and experiments are discussed, but I hope to give a sense of the current experimental landscape of the search for dark-matter axions.« less

Dark-matter QCD-axion searches.

PubMed

Rosenberg, Leslie J

2015-10-06

In the late 20th century, cosmology became a precision science. Now, at the beginning of the next century, the parameters describing how our universe evolved from the Big Bang are generally known to a few percent. One key parameter is the total mass density of the universe. Normal matter constitutes only a small fraction of the total mass density. Observations suggest this additional mass, the dark matter, is cold (that is, moving nonrelativistically in the early universe) and interacts feebly if at all with normal matter and radiation. There's no known such elementary particle, so the strong presumption is the dark matter consists of particle relics of a new kind left over from the Big Bang. One of the most important questions in science is the nature of this dark matter. One attractive particle dark-matter candidate is the axion. The axion is a hypothetical elementary particle arising in a simple and elegant extension to the standard model of particle physics that nulls otherwise observable CP-violating effects (where CP is the product of charge reversal C and parity inversion P) in quantum chromo dynamics (QCD). A light axion of mass 10(-(6-3)) eV (the invisible axion) would couple extraordinarily weakly to normal matter and radiation and would therefore be extremely difficult to detect in the laboratory. However, such an axion is a compelling dark-matter candidate and is therefore a target of a number of searches. Compared with other particle dark-matter candidates, the plausible range of axion dark-matter couplings and masses is narrowly constrained. This focused search range allows for definitive searches, where a nonobservation would seriously impugn the dark-matter QCD-axion hypothesis. Axion searches use a wide range of technologies, and the experiment sensitivities are now reaching likely dark-matter axion couplings and masses. This article is a selective overview of the current generation of sensitive axion searches. Not all techniques and experiments are discussed, but I hope to give a sense of the current experimental landscape of the search for dark-matter axions.

Dark-matter QCD-axion searches

PubMed Central

Rosenberg, Leslie J

2015-01-01

In the late 20th century, cosmology became a precision science. Now, at the beginning of the next century, the parameters describing how our universe evolved from the Big Bang are generally known to a few percent. One key parameter is the total mass density of the universe. Normal matter constitutes only a small fraction of the total mass density. Observations suggest this additional mass, the dark matter, is cold (that is, moving nonrelativistically in the early universe) and interacts feebly if at all with normal matter and radiation. There’s no known such elementary particle, so the strong presumption is the dark matter consists of particle relics of a new kind left over from the Big Bang. One of the most important questions in science is the nature of this dark matter. One attractive particle dark-matter candidate is the axion. The axion is a hypothetical elementary particle arising in a simple and elegant extension to the standard model of particle physics that nulls otherwise observable CP-violating effects (where CP is the product of charge reversal C and parity inversion P) in quantum chromo dynamics (QCD). A light axion of mass 10−(6–3) eV (the invisible axion) would couple extraordinarily weakly to normal matter and radiation and would therefore be extremely difficult to detect in the laboratory. However, such an axion is a compelling dark-matter candidate and is therefore a target of a number of searches. Compared with other particle dark-matter candidates, the plausible range of axion dark-matter couplings and masses is narrowly constrained. This focused search range allows for definitive searches, where a nonobservation would seriously impugn the dark-matter QCD-axion hypothesis. Axion searches use a wide range of technologies, and the experiment sensitivities are now reaching likely dark-matter axion couplings and masses. This article is a selective overview of the current generation of sensitive axion searches. Not all techniques and experiments are discussed, but I hope to give a sense of the current experimental landscape of the search for dark-matter axions. PMID:25583487

Deterministic radiative coupling of two semiconductor quantum dots to the optical mode of a photonic crystal nanocavity.

PubMed

Calic, M; Jarlov, C; Gallo, P; Dwir, B; Rudra, A; Kapon, E

2017-06-22

A system of two site-controlled semiconductor quantum dots (QDs) is deterministically integrated with a photonic crystal membrane nano-cavity. The two QDs are identified via their reproducible emission spectral features, and their coupling to the fundamental cavity mode is established by emission co-polarization and cavity feeding features. A theoretical model accounting for phonon interaction and pure dephasing reproduces the observed results and permits extraction of the light-matter coupling constant for this system. The demonstrated approach offers a platform for scaling up the integration of QD systems and nano-photonic elements for integrated quantum photonics applications.

Mutual interactions of phonons, rotons, and gravity

NASA Astrophysics Data System (ADS)

Nicolis, Alberto; Penco, Riccardo

2018-04-01

We introduce an effective point-particle action for generic particles living in a zero-temperature superfluid. This action describes the motion of the particles in the medium at equilibrium as well as their couplings to sound waves and generic fluid flows. While we place the emphasis on elementary excitations such as phonons and rotons, our formalism applies also to macroscopic objects such as vortex rings and rigid bodies interacting with long-wavelength fluid modes. Within our approach, we reproduce phonon decay and phonon-phonon scattering as predicted using a purely field-theoretic description of phonons. We also correct classic results by Landau and Khalatnikov on roton-phonon scattering. Finally, we discuss how phonons and rotons couple to gravity, and show that the former tend to float while the latter tend to sink but with rather peculiar trajectories. Our formalism can be easily extended to include (general) relativistic effects and couplings to additional matter fields. As such, it can be relevant in contexts as diverse as neutron star physics and light dark matter detection.

An effective Z'

DOE PAGES

Fox, Patrick J.; Liu, Jia; Tucker-Smith, David; ...

2011-12-06

We describe a method to couple Z' gauge bosons to the standard model (SM), without charging the SM fields under the U(1)', but instead through effective higher-dimension operators. This method allows complete control over the tree-level couplings of the Z' and does not require altering the structure of any of the SM couplings, nor does it contain anomalies or require introduction of fields in nonstandard SM representations. Moreover, such interactions arise from simple renormalizable extensions of the SM—the addition of vectorlike matter that mixes with SM fermions when the U(1)' is broken. We apply effective Z' models as explanations ofmore » various recent anomalies: the D0 same-sign dimuon asymmetry, the CDF W+di-jet excess and the CDF top forward-backward asymmetry. In the case of the W+di-jet excess we also discuss several complementary analyses that may shed light on the nature of the discrepancy. We consider the possibility of non-Abelian groups, and discuss implications for the phenomenology of dark matter as well.« less

Phase transition of light in cavity QED lattices.

PubMed

Schiró, M; Bordyuh, M; Oztop, B; Türeci, H E

2012-08-03

Systems of strongly interacting atoms and photons, which can be realized wiring up individual cavity QED systems into lattices, are perceived as a new platform for quantum simulation. While sharing important properties with other systems of interacting quantum particles, here we argue that the nature of light-matter interaction gives rise to unique features with no analogs in condensed matter or atomic physics setups. By discussing the physics of a lattice model of delocalized photons coupled locally with two-level systems through the elementary light-matter interaction described by the Rabi model, we argue that the inclusion of counterrotating terms, so far neglected, is crucial to stabilize finite-density quantum phases of correlated photons out of the vacuum, with no need for an artificially engineered chemical potential. We show that the competition between photon delocalization and Rabi nonlinearity drives the system across a novel Z(2) parity symmetry-breaking quantum criticality between two gapped phases that share similarities with the Dicke transition of quantum optics and the Ising critical point of quantum magnetism. We discuss the phase diagram as well as the low-energy excitation spectrum and present analytic estimates for critical quantities.

Sound Velocity Bound and Neutron Stars

DOE PAGES

Bedaque, Paulo; Steiner, Andrew W.

2015-01-21

A conjecture that the velocity of sound in any medium is smaller than the velocity of light in vacuum divided by sqrt(3). Simple arguments support this bound in nonrelativistic and/or weakly coupled theories. Moreover, the bound has been demonstrated in several classes of strongly coupled theories with gravity duals and is saturated only in conformal theories. Here, we point out that the existence of neutron stars with masses around two solar masses combined with the knowledge of the equation of state of hadronic matter at low densities is in strong tension with this bound.

Deformation Behavior of Ultra-Strong and Ductile Mg-Gd-Y-Zn-Zr Alloy with Bimodal Microstructure

NASA Astrophysics Data System (ADS)

Xu, C.; Fan, G. H.; Nakata, T.; Liang, X.; Chi, Y. Q.; Qiao, X. G.; Cao, G. J.; Zhang, T. T.; Huang, M.; Miao, K. S.; Zheng, M. Y.; Kamado, S.; Xie, H. L.

2018-02-01

An ultra-strong and ductile Mg-8.2Gd-3.8Y-1Zn-0.4Zr (wt pct) alloy was developed by using hot extrusion to modify the microstructure via forced-air cooling and an artificial aging treatment. A superior strength-ductility balance was obtained that had a tensile yield strength of 466 MPa and an elongation to failure of 14.5 pct. The local strain evolution during the in situ testing of the ultra-strong and ductile alloy was quantitatively analyzed with high-resolution electron backscattered diffraction and digital image correlation. The fracture behavior during the tensile test was characterized by synchrotron X-ray tomography along with SEM and STEM observations. The alloy showed a bimodal microstructure, consisting of dynamically recrystallized (DRXed) grains with random orientations and elongated hot-worked grains with < { 10{\\bar{1}}0} > parallel to the extrusion direction. The DRXed grains were deformed by the basal <;a> slip and the hot-worked grains were deformed by the prismatic slip dominantly. The strain evolution analysis indicated that the multilayered structure relaxed the strain localization via strain transfer from the DRXed to the hot-worked regions, which led to the high ductility of the alloy. Precipitation of the γ' on basal planes and the β' phases on the prismatic planes of the α-Mg generated closed volumes, which enhanced the strength by pinning dislocations effectively, and contributed to the high ductility by impeding the propagation of micro-cracks inside the grains. The deformation incompatibility between the hot-worked grains and the arched block-shaped long-period stacking ordered (LPSO) phases induced the crack initiation and propagation, which fractured the alloy.

Microscale characterization of dissolved organic matter production and uptake in marine microbial mat communities

NASA Technical Reports Server (NTRS)

Paerl, H. W.; Bebout, B. M.; Joye, S. B.; Des Marais, D. J.

1993-01-01

Intertidal marine microbial mats exhibited biologically mediated uptake of low molecular weight dissolved organic matter (DOM), including D-glucose, acetate, and an L-amino acid mixture at trace concentrations. Uptake of all compounds occurred in darkness, but was frequently enhanced under natural illumination. The photosystem 2 inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethyl urea (DCMU) generally failed to inhibit light-stimulated DOM uptake. Occasionally, light plus DCMU-amended treatments led to uptake rates higher than light-incubated samples, possibly due to phototrophic bacteria present in subsurface anoxic layers. Uptake was similar with either 3H- or 14C-labeled substrates, indicating that recycling of labeled CO2 via photosynthetic fixation was not interfering with measurements of light-stimulated DOM uptake. Microautoradiographs showed a variety of pigmented and nonpigmented bacteria and, to a lesser extent, cyanobacteria and eucaryotic microalgae involved in light-mediated DOM uptake. Light-stimulated DOM uptake was often observed in bacteria associated with sheaths and mucilage surrounding filamentous cyanobacteria, revealing a close association of organisms taking up DOM with photoautotrophic members of the mat community. The capacity for dark- and light-mediated heterotrophy, coupled to efficient retention of fixed carbon in the mat community, may help optimize net production and accretion of mats, even in oligotrophic waters.

Electromagnon Resonance at Room Temperature with Gigantic Magnetochromism

NASA Astrophysics Data System (ADS)

Shishikura, H.; Tokunaga, Y.; Takahashi, Y.; Masuda, R.; Taguchi, Y.; Kaneko, Y.; Tokura, Y.

2018-04-01

The elementary excitation characteristic of magnetoelectric (ME) multiferroics is a magnon endowed with electric activity, which is referred to as an electromagnon. The electromagnon resonance mediated by the bilinear exchange coupling potentially exhibits strong terahertz light-matter interaction with optical properties different from the conventional magnon excitation. Here we report the robust electromagnon resonance on helimagnetic Y -type hexaferrites in a wide temperature range including room temperature. Furthermore, the efficient magnetic field controls of the electromagnon are demonstrated on the flexible spin structure of these compounds, leading to the generation or annihilation of the resonance as well as the large resonance energy shift. These terahertz characteristics of the electromagnon exemplify the versatile magneto-optical functionality driven by the ME coupling in multiferroics, paving a way for possible terahertz applications as well as terahertz control of a magnetic state of matter.

Dark matter direct detection of a fermionic singlet at one loop

NASA Astrophysics Data System (ADS)

Herrero-García, Juan; Molinaro, Emiliano; Schmidt, Michael A.

2018-06-01

The strong direct detection limits could be pointing to dark matter - nucleus scattering at loop level. We study in detail the prototype example of an electroweak singlet (Dirac or Majorana) dark matter fermion coupled to an extended dark sector, which is composed of a new fermion and a new scalar. Given the strong limits on colored particles from direct and indirect searches we assume that the fields of the new dark sector are color singlets. We outline the possible simplified models, including the well-motivated cases in which the extra scalar or fermion is a Standard Model particle, as well as the possible connection to neutrino masses. We compute the contributions to direct detection from the photon, the Z and the Higgs penguins for arbitrary quantum numbers of the dark sector. Furthermore, we derive compact expressions in certain limits, i.e., when all new particles are heavier than the dark matter mass and when the fermion running in the loop is light, like a Standard Model lepton. We study in detail the predicted direct detection rate and how current and future direct detection limits constrain the model parameters. In case dark matter couples directly to Standard Model leptons we find an interesting interplay between lepton flavor violation, direct detection and the observed relic abundance.

Inflatable Dark Matter.

PubMed

Davoudiasl, Hooman; Hooper, Dan; McDermott, Samuel D

2016-01-22

We describe a general scenario, dubbed "inflatable dark matter," in which the density of dark matter particles can be reduced through a short period of late-time inflation in the early Universe. The overproduction of dark matter that is predicted within many, otherwise, well-motivated models of new physics can be elegantly remedied within this context. Thermal relics that would, otherwise, be disfavored can easily be accommodated within this class of scenarios, including dark matter candidates that are very heavy or very light. Furthermore, the nonthermal abundance of grand unified theory or Planck scale axions can be brought to acceptable levels without invoking anthropic tuning of initial conditions. A period of late-time inflation could have occurred over a wide range of scales from ∼MeV to the weak scale or above, and could have been triggered by physics within a hidden sector, with small but not necessarily negligible couplings to the standard model.

The cryogenic dark matter search low ionization-threshold experiment

NASA Astrophysics Data System (ADS)

Basu Thakur, Ritoban

Over 80 years ago we discovered the presence of Dark Matter in our universe. Endeavors in astronomy and cosmology are in consensus with ever improving precision that Dark Matter constitutes an essential 27% of our universe. The Standard Model of Particle Physics does not provide any answers to the Dark Matter problem. It is imperative that we understand Dark Matter and discover its fundamental nature. This is because, alongside other important factors, Dark Matter is responsible for formation of structure in our universe. The very construct in which we sit is defined by its abundance. The Milky Way galaxy, hence life, wouldn't have formed if small over densities of Dark Matter had not caused sufficient accretion of stellar material. Marvelous experiments have been designed based on basic notions to directly and indirectly study Dark Matter, and the Cryogenic Dark Matter Search (CDMS) experiment has been a pioneer and forerunner in the direct detection field. Generations of the CDMS experiment were designed with advanced scientific upgrades to detect Dark Matter particles of mass O(100) GeV/c2. This mass-scale was set primarily by predictions from Super Symmetry. Around 2013 the canonical SUSY predictions were losing some ground and several observations (rather hints of signals) from various experiments indicated to the possibility of lighter Dark Matter of mass O(10) GeV/c2. While the SuperCDMS experiment was probing the regular parameter space, the CDMSlite experiment was conceived to dedicatedly search for light Dark Matter using a novel technology. "CDMSlite" stands for CDMS - low ionization threshold experiment. Here we utilize a unique electron phonon coupling mechanism to measure ionization generated by scattering of light particles. Typically signals from such low energy recoils would be washed under instrumental noise.In CDMSlite via generation of Luke-Neganov phonons we can detect the small ionization energies, amplified in phonon modes during charge transport. This technology allows us to reach very low thresholds and reliably measure and investigate low energy recoils from light Dark Matter particles. This thesis describes the physics behind CDMSlite, the experimenta design and the first science results from CDMSlite operated at the Soudan Underground Laboratory.

The Cryogenic Dark Matter Search low ionization-threshold experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Basu Thakur, Ritoban

2014-01-01

Over 80 years ago we discovered the presence of Dark Matter in our universe. Endeavors in astronomy and cosmology are in consensus with ever improving precision that Dark Matter constitutes an essential 27% of our universe. The Standard Model of Particle Physics does not provide any answers to the Dark Matter problem. It is imperative that we understand Dark Matter and discover its fundamental nature. This is because, alongside other important factors, Dark Matter is responsible for formation of structure in our universe. The very construct in which we sit is defined by its abundance. The Milky Way galaxy, hencemore » life, wouldn't have formed if small over densities of Dark Matter had not caused sufficient accretion of stellar material. Marvelous experiments have been designed based on basic notions to directly and in-directly study Dark Matter, and the Cryogenic Dark Matter Search (CDMS) experiment has been a pioneer and forerunner in the direct detection field. Generations of the CDMS experiment were designed with advanced scientific upgrades to detect Dark Matter particles of mass O(100) GeV/c 2. This mass-scale was set primarily by predictions from Super Symmetry. Around 2013 the canonical SUSY predictions were losing some ground and several observations (rather hints of signals) from various experiments indicated to the possibility of lighter Dark Matter of mass O(10) GeV/c 2. While the SuperCDMS experiment was probing the regular parameter space, the CDMSlite experiment was conceived to dedicatedly search for light Dark Matter using a novel technology. "CDMSlite" stands for CDMS - low ionization threshold experiment. Here we utilize a unique electron phonon coupling mechanism to measure ionization generated by scattering of light particles. Typically signals from such low energy recoils would be washed under instrumental noise. In CDMSlite via generation of Luke-Neganov phonons we can detect the small ionization energies, amplified in phonon modes during charge transport. This technology allows us to reach very low thresholds and reliably measure and investigate low energy recoils from light Dark Matter particles. This thesis describes the physics behind CDMSlite, the experimental design and the first science results from CDMSlite operated at the Soudan Underground Laboratory.« less

Invisible axionlike dark matter from the electroweak bosonic seesaw mechanism

NASA Astrophysics Data System (ADS)

Ishida, Hiroyuki; Matsuzaki, Shinya; Yamaguchi, Yuya

2016-11-01

We explore a model based on the classically scale-invariant standard model (SM) with a strongly coupled vectorlike dynamics, which is called hypercolor (HC). The scale symmetry is dynamically broken by the vectorlike condensation at the TeV scale, so that the SM Higgs acquires the negative mass squared by the bosonic seesaw mechanism to realize the electroweak symmetry breaking. An elementary pseudoscalar S is introduced to give masses for the composite Nambu-Goldstone bosons (HC pions): The HC pion can be a good target to explore through a diphoton channel at the LHC. As a consequence of the bosonic seesaw, the fluctuating mode of S , which we call s , develops tiny couplings to the SM particles and is predicted to be very light. The s predominantly decays to a diphoton and can behave as invisible axionlike dark matter. The mass of the s dark matter is constrained by currently available cosmological and astrophysical limits to be 10-4 eV ≲ms≲1 eV . We find that a sufficient amount of relic abundance for the s dark matter can be accumulated via the coherent oscillation. The detection potential in microwave cavity experiments is also addressed.

Decays of a NMSSM CP-odd Higgs in the low-mass region

NASA Astrophysics Data System (ADS)

Domingo, Florian

2017-03-01

A popular regime in the NMSSM parameter space involves a light CP-odd Higgs A 1. This scenario has consequences for e.g. light singlino Dark Matter annihilating in the A 1-funnel. In order to confront the pseudoscalar to experimental limits such as flavour observables, Upsilon decays or Beam-Dump experiments, it is necessary to control the interactions of this particle with hadronic matter and derive the corresponding decays. The partonic description cannot be relied upon for masses close to {m_A}{_1} ˜ 1GeV and we employ a chiral lagrangian, then extended to a spectator model for somewhat larger masses, to describe the interplay of the CP-odd Higgs with hadrons. Interestingly, a mixing can develop between A 1 and neutral pseudoscalar mesons, leading to substantial hadronic decays and a coupling of A 1 to the chiral anomaly. Additionally, quartic A 1-meson couplings induce tri-meson decays of the Higgs pseudoscalar. We investigate these effects and propose an estimate of the Higgs widths for masses below {m_A}{_1} ≲ 3 GeV. While we focus on the case of the NMSSM, our results are applicable to a large class of models.

Cavity-assisted mesoscopic transport of fermions: Coherent and dissipative dynamics

NASA Astrophysics Data System (ADS)

Hagenmüller, David; Schütz, Stefan; Schachenmayer, Johannes; Genes, Claudiu; Pupillo, Guido

2018-05-01

We study the interplay between charge transport and light-matter interactions in a confined geometry by considering an open, mesoscopic chain of two-orbital systems resonantly coupled to a single bosonic mode close to its vacuum state. We introduce and benchmark different methods based on self-consistent solutions of nonequilibrium Green's functions and numerical simulations of the quantum master equation, and derive both analytical and numerical results. It is shown that in the dissipative regime where the cavity photon decay rate is the largest parameter, the light-matter coupling is responsible for a steady-state current enhancement scaling with the cooperativity parameter. We further identify different regimes of interest depending on the ratio between the cavity decay rate and the electronic bandwidth. Considering the situation where the lower band has a vanishing bandwidth, we show that for a high-finesse cavity, the properties of the resonant Bloch state in the upper band are transferred to the lower one, giving rise to a delocalized state along the chain. Conversely, in the dissipative regime with low-cavity quality factors, we find that the current enhancement is due to a collective decay of populations from the upper to the lower band.

Enhanced coupling of light into a turbid medium through microscopic interface engineering

PubMed Central

Thompson, Jonathan V.; Hokr, Brett H.; Kim, Wihan; Ballmann, Charles W.; Applegate, Brian E.; Jo, Javier; Yamilov, Alexey; Cao, Hui; Scully, Marlan O.; Yakovlev, Vladislav V.

2017-01-01

There are many optical detection and sensing methods used today that provide powerful ways to diagnose, characterize, and study materials. For example, the measurement of spontaneous Raman scattering allows for remote detection and identification of chemicals. Many other optical techniques provide unique solutions to learn about biological, chemical, and even structural systems. However, when these systems exist in a highly scattering or turbid medium, the optical scattering effects reduce the effectiveness of these methods. In this article, we demonstrate a method to engineer the geometry of the optical interface of a turbid medium, thereby drastically enhancing the coupling efficiency of light into the material. This enhanced optical coupling means that light incident on the material will penetrate deeper into (and through) the medium. It also means that light thus injected into the material will have an enhanced interaction time with particles contained within the material. These results show that, by using the multiple scattering of light in a turbid medium, enhanced light–matter interaction can be achieved; this has a direct impact on spectroscopic methods such as Raman scattering and fluorescence detection in highly scattering regimes. Furthermore, the enhanced penetration depth achieved by this method will directly impact optical techniques that have previously been limited by the inability to deposit sufficient amounts of optical energy below or through highly scattering layers. PMID:28701381

Printing soft matter in three dimensions.

PubMed

Truby, Ryan L; Lewis, Jennifer A

2016-12-14

Light- and ink-based three-dimensional (3D) printing methods allow the rapid design and fabrication of materials without the need for expensive tooling, dies or lithographic masks. They have led to an era of manufacturing in which computers can control the fabrication of soft matter that has tunable mechanical, electrical and other functional properties. The expanding range of printable materials, coupled with the ability to programmably control their composition and architecture across various length scales, is driving innovation in myriad applications. This is illustrated by examples of biologically inspired composites, shape-morphing systems, soft sensors and robotics that only additive manufacturing can produce.

Printing soft matter in three dimensions

NASA Astrophysics Data System (ADS)

Truby, Ryan L.; Lewis, Jennifer A.

2016-12-01

Light- and ink-based three-dimensional (3D) printing methods allow the rapid design and fabrication of materials without the need for expensive tooling, dies or lithographic masks. They have led to an era of manufacturing in which computers can control the fabrication of soft matter that has tunable mechanical, electrical and other functional properties. The expanding range of printable materials, coupled with the ability to programmably control their composition and architecture across various length scales, is driving innovation in myriad applications. This is illustrated by examples of biologically inspired composites, shape-morphing systems, soft sensors and robotics that only additive manufacturing can produce.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daido, Ryuji; Takahashi, Fuminobu; Yin, Wen, E-mail: daido@tuhep.phys.tohoku.ac.jp, E-mail: fumi@tuhep.phys.tohoku.ac.jp, E-mail: wyin@ihep.ac.cn

We propose a scenario where both inflation and dark matter are described by a single axion-like particle (ALP) in a unified manner. In a class of the minimal axion hilltop inflation, the effective masses at the maximum and mimimum of the potential have equal magnitude but opposite sign, so that the ALP inflaton is light both during inflation and in the true vacuum. After inflation, most of the ALPs decay and evaporate into plasma through a coupling to photons, and the remaining ones become dark matter. We find that the observed CMB and matter power spectrum as well as themore » dark matter abundance point to an ALP of mass m {sub φ} = O(0.01) eV and the axion-photon coupling g {sub φ} {sub γ} {sub γ} = O(10{sup −11}) GeV{sup −1}: the ALP miracle . The suggested parameter region is within the reach of the next generation axion helioscope, IAXO, and high-intensity laser experiments in the future. Furthermore, thermalized ALPs contribute to hot dark matter and its abundance is given in terms of the effective number of extra neutrino species, Δ N {sub eff} ≅ 0.03, which can be tested by the future CMB and BAO observations. We also discuss a case with multiple ALPs, where the coupling to photons can be enhanced in the early Universe by an order of magnitude or more, which enlarges the parameter space for the ALP miracle. The heavy ALP plays a role of the waterfall field in hybrid inflation, and reheats the Universe, and it can be searched for in various experiments such as SHiP.« less

Sensitivity of Atom Interferometry to Ultralight Scalar Field Dark Matter.

PubMed

Geraci, Andrew A; Derevianko, Andrei

2016-12-23

We discuss the use of atom interferometry as a tool to search for dark matter (DM) composed of virialized ultralight fields (VULFs). Previous work on VULF DM detection using accelerometers has considered the possibility of equivalence-principle-violating effects whereby gradients in the dark matter field can directly produce relative accelerations between media of differing composition. In atom interferometers, we find that time-varying phase signals induced by coherent oscillations of DM fields can also arise due to changes in the atom rest mass that can occur between light pulses throughout the interferometer sequence as well as changes in Earth's gravitational field. We estimate that several orders of magnitude of unexplored phase space for VULF DM couplings can be probed due to these new effects.

Microwave photonics with superconducting quantum circuits

NASA Astrophysics Data System (ADS)

Gu, Xiu; Kockum, Anton Frisk; Miranowicz, Adam; Liu, Yu-xi; Nori, Franco

2017-11-01

In the past 20 years, impressive progress has been made both experimentally and theoretically in superconducting quantum circuits, which provide a platform for manipulating microwave photons. This emerging field of superconducting quantum microwave circuits has been driven by many new interesting phenomena in microwave photonics and quantum information processing. For instance, the interaction between superconducting quantum circuits and single microwave photons can reach the regimes of strong, ultra-strong, and even deep-strong coupling. Many higher-order effects, unusual and less familiar in traditional cavity quantum electrodynamics with natural atoms, have been experimentally observed, e.g., giant Kerr effects, multi-photon processes, and single-atom induced bistability of microwave photons. These developments may lead to improved understanding of the counterintuitive properties of quantum mechanics, and speed up applications ranging from microwave photonics to superconducting quantum information processing. In this article, we review experimental and theoretical progress in microwave photonics with superconducting quantum circuits. We hope that this global review can provide a useful roadmap for this rapidly developing field.

Deterministic Coupling of Quantum Emitters in 2D Materials to Plasmonic Nanocavity Arrays.

PubMed

Tran, Toan Trong; Wang, Danqing; Xu, Zai-Quan; Yang, Ankun; Toth, Milos; Odom, Teri W; Aharonovich, Igor

2017-04-12

Quantum emitters in two-dimensional materials are promising candidates for studies of light-matter interaction and next generation, integrated on-chip quantum nanophotonics. However, the realization of integrated nanophotonic systems requires the coupling of emitters to optical cavities and resonators. In this work, we demonstrate hybrid systems in which quantum emitters in 2D hexagonal boron nitride (hBN) are deterministically coupled to high-quality plasmonic nanocavity arrays. The plasmonic nanoparticle arrays offer a high-quality, low-loss cavity in the same spectral range as the quantum emitters in hBN. The coupled emitters exhibit enhanced emission rates and reduced fluorescence lifetimes, consistent with Purcell enhancement in the weak coupling regime. Our results provide the foundation for a versatile approach for achieving scalable, integrated hybrid systems based on low-loss plasmonic nanoparticle arrays and 2D materials.

Observation of Tunable Charged Exciton Polaritons in Hybrid Monolayer WS2-Plasmonic Nanoantenna System.

PubMed

Cuadra, Jorge; Baranov, Denis G; Wersäll, Martin; Verre, Ruggero; Antosiewicz, Tomasz J; Shegai, Timur

2018-03-14

Formation of dressed light-matter states in optical structures, manifested as Rabi splitting of the eigen energies of a coupled system, is one of the key effects in quantum optics. In pursuing this regime with semiconductors, light is usually made to interact with excitons, electrically neutral quasiparticles of semiconductors; meanwhile interactions with charged three-particle states, trions, have received little attention. Here, we report on strong interaction between localized surface plasmons in silver nanoprisms and excitons and trions in monolayer tungsten disulfide (WS 2 ). We show that the plasmon-exciton interactions in this system can be efficiently tuned by controlling the charged versus neutral exciton contribution to the coupling process. In particular, we show that a stable trion state emerges and couples efficiently to the plasmon resonance at low temperature by forming three bright intermixed plasmon-exciton-trion polariton states. Our findings open up a possibility to exploit electrically charged polaritons at the single nanoparticle level.

Confronting Seiberg's duality with r duality in N=1 supersymmetric QCD

NASA Astrophysics Data System (ADS)

Shifman, M.; Yung, A.

2012-09-01

Systematizing our results on r duality obtained previously we focus on comparing r duality with the generalized Seiberg duality in the r vacua of N=2 and N=1 super-Yang-Mills theories with the U(N) gauge group and Nf matter flavors (Nf>N). The number of condensed (s)quarks r is assumed to be in the interval (2)/(3)Nf

Radiative natural supersymmetry: Reconciling electroweak fine-tuning and the Higgs boson mass

NASA Astrophysics Data System (ADS)

Baer, Howard; Barger, Vernon; Huang, Peisi; Mickelson, Dan; Mustafayev, Azar; Tata, Xerxes

2013-06-01

Models of natural supersymmetry seek to solve the little hierarchy problem by positing a spectrum of light Higgsinos ≲200-300GeV and light top squarks ≲600GeV along with very heavy squarks and TeV-scale gluinos. Such models have low electroweak fine-tuning and satisfy the LHC constraints. However, in the context of the minimal supersymmetric standard model, they predict too low a value of mh, are frequently in conflict with the measured b→sγ branching fraction, and the relic density of thermally produced Higgsino-like weakly interacting massive particles (WIMPs) falls well below dark matter measurements. We propose a framework dubbed radiative natural supersymmetry (RNS), which can be realized within the minimal supersymmetric standard model (avoiding the addition of extra exotic matter) and which maintains features such as gauge coupling unification and radiative electroweak symmetry breaking. The RNS model can be generated from supersymmetry (SUSY) grand unified theory type models with nonuniversal Higgs masses. Allowing for high-scale soft SUSY breaking Higgs mass mHu>m0 leads to automatic cancellations during renormalization group running and to radiatively-induced low fine-tuning at the electroweak scale. Coupled with large mixing in the top-squark sector, RNS allows for fine-tuning at the 3%-10% level with TeV-scale top squarks and a 125 GeV light Higgs scalar h. The model allows for at least a partial solution to the SUSY flavor, CP, and gravitino problems since first-/second-generation scalars (and the gravitino) may exist in the 10-30 TeV regime. We outline some possible signatures for RNS at the LHC, such as the appearance of low invariant mass opposite-sign isolated dileptons from gluino cascade decays. The smoking gun signature for RNS is the appearance of light Higgsinos at a linear e+e- collider. If the strong CP problem is solved by the Peccei-Quinn mechanism, then RNS naturally accommodates mixed axion-Higgsino cold dark matter, where the light Higgsino-like WIMPs—which in this case make up only a fraction of the measured relic abundance—should be detectable at upcoming WIMP detectors.

Tuning the photon statistics of a strongly coupled nanophotonic system

NASA Astrophysics Data System (ADS)

Dory, Constantin; Fischer, Kevin A.; Müller, Kai; Lagoudakis, Konstantinos G.; Sarmiento, Tomas; Rundquist, Armand; Zhang, Jingyuan L.; Kelaita, Yousif; Sapra, Neil V.; Vučković, Jelena

2017-02-01

We investigate the dynamics of single- and multiphoton emission from detuned strongly coupled systems based on the quantum-dot-photonic-crystal resonator platform. Transmitting light through such systems can generate a range of nonclassical states of light with tunable photon counting statistics due to the nonlinear ladder of hybridized light-matter states. By controlling the detuning between emitter and resonator, the transmission can be tuned to strongly enhance either single- or two-photon emission processes. Despite the strongly dissipative nature of these systems, we find that by utilizing a self-homodyne interference technique combined with frequency filtering we are able to find a strong two-photon component of the emission in the multiphoton regime. In order to explain our correlation measurements, we propose rate equation models that capture the dominant processes of emission in both the single- and multiphoton regimes. These models are then supported by quantum-optical simulations that fully capture the frequency filtering of emission from our solid-state system.

From polariton condensates to highly photonic quantum degenerate states of bosonic matter

PubMed Central

Aßmann, Marc; Tempel, Jean-Sebastian; Veit, Franziska; Bayer, Manfred; Rahimi-Iman, Arash; Löffler, Andreas; Höfling, Sven; Reitzenstein, Stephan; Worschech, Lukas; Forchel, Alfred

2011-01-01

Bose–Einstein condensation (BEC) is a thermodynamic phase transition of an interacting Bose gas. Its key signatures are remarkable quantum effects like superfluidity and a phonon-like Bogoliubov excitation spectrum, which have been verified for atomic BECs. In the solid state, BEC of exciton–polaritons has been reported. Polaritons are strongly coupled light-matter quasiparticles in semiconductor microcavities and composite bosons. However, they are subject to dephasing and decay and need external pumping to reach a steady state. Accordingly the polariton BEC is a nonequilibrium process of a degenerate polariton gas in self-equilibrium, but out of equilibrium with the baths it is coupled to and therefore deviates from the thermodynamic phase transition seen in atomic BECs. Here we show that key signatures of BEC can even be observed without fulfilling the self-equilibrium condition in a highly photonic quantum degenerate nonequilibrium system. PMID:21245353

Hyperspectral fluorescence imaging coupled with multivariate image analysis techniques for contaminant screening of leafy greens

NASA Astrophysics Data System (ADS)

Everard, Colm D.; Kim, Moon S.; Lee, Hoyoung

2014-05-01

The production of contaminant free fresh fruit and vegetables is needed to reduce foodborne illnesses and related costs. Leafy greens grown in the field can be susceptible to fecal matter contamination from uncontrolled livestock and wild animals entering the field. Pathogenic bacteria can be transferred via fecal matter and several outbreaks of E.coli O157:H7 have been associated with the consumption of leafy greens. This study examines the use of hyperspectral fluorescence imaging coupled with multivariate image analysis to detect fecal contamination on Spinach leaves (Spinacia oleracea). Hyperspectral fluorescence images from 464 to 800 nm were captured; ultraviolet excitation was supplied by two LED-based line light sources at 370 nm. Key wavelengths and algorithms useful for a contaminant screening optical imaging device were identified and developed, respectively. A non-invasive screening device has the potential to reduce the harmful consequences of foodborne illnesses.

Dark interactions and cosmological fine-tuning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quartin, Miguel; Calvao, Mauricio O; Joras, Sergio E

2008-05-15

Cosmological models involving an interaction between dark matter and dark energy have been proposed in order to solve the so-called coincidence problem. Different forms of coupling have been studied, but there have been claims that observational data seem to narrow (some of) them down to something annoyingly close to the {Lambda}CDM (CDM: cold dark matter) model, thus greatly reducing their ability to deal with the problem in the first place. The smallness problem of the initial energy density of dark energy has also been a target of cosmological models in recent years. Making use of a moderately general coupling scheme,more » this paper aims to unite these different approaches and shed some light on whether this class of models has any true perspective in suppressing the aforementioned issues that plague our current understanding of the universe, in a quantitative and unambiguous way.« less

Revisiting simplified dark matter models in terms of AMS-02 and Fermi-LAT

NASA Astrophysics Data System (ADS)

Li, Tong

2018-01-01

We perform an analysis of the simplified dark matter models in the light of cosmic ray observables by AMS-02 and Fermi-LAT. We assume fermion, scalar or vector dark matter particle with a leptophobic spin-0 mediator that couples only to Standard Model quarks and dark matter via scalar and/or pseudo-scalar bilinear. The propagation and injection parameters of cosmic rays are determined by the observed fluxes of nuclei from AMS-02. We find that the AMS-02 observations are consistent with the dark matter framework within the uncertainties. The AMS-02 antiproton data prefer 30 (50) GeV - 5 TeV dark matter mass and require an effective annihilation cross section in the region of 4 × 10-27 (7 × 10-27) - 4 × 10-24 cm3/s for the simplified fermion (scalar and vector) dark matter models. The cross sections below 2 × 10-26 cm3/s can evade the constraint from Fermi-LAT dwarf galaxies for about 100 GeV dark matter mass.

Exploring vacuum birefringence based on a 100 PW laser and an x-ray free electron laser beam

NASA Astrophysics Data System (ADS)

Shen, Baifei; Bu, Zhigang; Xu, Jiancai; Xu, Tongjun; Ji, Liangliang; Li, Ruxin; Xu, Zhizhan

2018-04-01

Exploring vacuum birefringence with the station of extreme light at Shanghai Coherent Light Facility is considered. Laser pulses of intensity beyond 1023 W cm-2 are capable of polarizing the vacuum due to the ultra-strong electro-magnetic fields. The subtle difference of the vacuum refractive indexes along electric and magnetic fields leads to a birefringence effect for lights propagating through. The vacuum birefringence effect can now be captured by colliding a hard x-ray free electron laser (XFEL) beam with a high-power laser. The initial XFEL beam of pure linear polarization is predicated to gain a very small ellipticity after passing through the laser stimulated vacuum. Various interaction geometries are considered, showing that the estimated ellipticity lies between 1.8 × 10-10 and 10-9 for a 100 PW laser interacting with a 12.9 keV XFEL beam, approaching the threshold for todays’ polarity detection technique. The detailed experimental set-up is designed, including the polarimeter, the focusing compound refractive lens and the optical path. When taking into account the efficiencies of the x-ray instruments, it is found that about 10 polarization-flipped x-ray photons can be detected for a single shot for our design. Considering the background noise level, accumulating runs are necessary to obtain high confident measurement.

Using LGI experiments to achieve better understanding of pedestal-edge coupling in NSTX-U

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zhehui

2015-02-23

PowerPoint presentation. Latest advances in granule or dust injection technologies, fast and high-resolution imaging, together with micro-/nano-structured material fabrication, provide new opportunities to examine plasma-material interaction (PMI) in magnetic fusion environment. Some of our previous work in these areas is summarized. The upcoming LGI experiments in NSTX-U will shed new light on granular matter transport in the pedestal-edge region. In addition to particle control, these results can also be used for code validation and achieving better understanding of pedestal-edge coupling in fusion plasmas in both NSTX-U and others.

Split-orientation-modulated plasmon coupling in disk/sector dimers

NASA Astrophysics Data System (ADS)

Zhu, Xupeng; Chen, Yiqin; Shi, Huimin; Zhang, Shi; Liu, Quanhui; Duan, Huigao

2017-06-01

The coupled asymmetric plasmonic nanostructures allow more compact nanophotonics integration and easier optical control in practical applications, such as directional scattering and near-field control. Here, we carried out a systematic and in-depth study on the plasmonic coupling of an asymmetric gold disk/sector dimer, and investigated the light-matter interaction in such an asymmetric coupled complex nanostructures. The results demonstrated that the positions and the intensity of plasmon resonance peak as well as the spatial distribution of electric fields around the surface in the coupled disk/sector dimer can be tuned by changing the azimuth angle of the gold sector. Based on Simpson-Peterson approximation, we proposed a model to understand the obtained plasmon properties of asymmetric coupled disk/sector dimers by introducing an offset parameter between the geometry center and dipole center of the sector. The experimental results agree well with the simulations. Our study provides an insight to tune the plasmon coupling behavior via adjusting the plasmon dipole center position in coupling systems.

Tuning the Photon Statistics of a Strongly Coupled Nanophotonic System

NASA Astrophysics Data System (ADS)

Dory, C.; Fischer, K. A.; Müller, K.; Lagoudakis, K. G.; Sarmiento, T.; Rundquist, A.; Zhang, J. L.; Kelaita, Y.; Sapra, N. V.; Vučković, J.

Strongly coupled quantum-dot-photonic-crystal cavity systems provide a nonlinear ladder of hybridized light-matter states, which are a promising platform for non-classical light generation. The transmission of light through such systems enables light generation with tunable photon counting statistics. By detuning the frequencies of quantum emitter and cavity, we can tune the transmission of light to strongly enhance either single- or two-photon emission processes. However, these nanophotonic systems show a strongly dissipative nature and classical light obscures any quantum character of the emission. In this work, we utilize a self-homodyne interference technique combined with frequency-filtering to overcome this obstacle. This allows us to generate emission with a strong two-photon component in the multi-photon regime, where we measure a second-order coherence value of g (2) [ 0 ] = 1 . 490 +/- 0 . 034 . We propose rate equation models that capture the dominant processes of emission both in the single- and multi-photon regimes and support them by quantum-optical simulations that fully capture the frequency filtering of emission from our solid-state system. Finally, we simulate a third-order coherence value of g (3) [ 0 ] = 0 . 872 +/- 0 . 021 . Army Research Office (ARO) (W911NF1310309), National Science Foundation (1503759), Stanford Graduate Fellowship.

Evolution of a hybrid micro-macro entangled state of the qubit-oscillator system via the generalized rotating wave approximation

NASA Astrophysics Data System (ADS)

Chakrabarti, R.; Yogesh, V.

2016-04-01

We study the evolution of the hybrid entangled states in a bipartite (ultra) strongly coupled qubit-oscillator system. Using the generalized rotating wave approximation the reduced density matrices of the qubit and the oscillator are obtained. The reduced density matrix of the oscillator yields the phase space quasi probability distributions such as the diagonal P-representation, the Wigner W-distribution and the Husimi Q-function. In the strong coupling regime the Q-function evolves to uniformly separated macroscopically distinct Gaussian peaks representing ‘kitten’ states at certain specified times that depend on multiple time scales present in the interacting system. The ultrastrong coupling strength of the interaction triggers appearance of a large number of modes that quickly develop a randomization of their phase relationships. A stochastic averaging of the dynamical quantities sets in, and leads to the decoherence of the system. The delocalization in the phase space of the oscillator is studied by using the Wehrl entropy. The negativity of the W-distribution reflects the departure of the oscillator from the classical states, and allows us to study the underlying differences between various information-theoretic measures such as the Wehrl entropy and the Wigner entropy. Other features of nonclassicality such as the existence of the squeezed states and appearance of negative values of the Mandel parameter are realized during the course of evolution of the bipartite system. In the parametric regime studied here these properties do not survive in the time-averaged limit.

Seeing with the nano-eye: accessing structure, function, and dynamics of matter on its natural length and time scales

NASA Astrophysics Data System (ADS)

Raschke, Markus

2015-03-01

To understand and ultimately control the properties of most functional materials, from molecular soft-matter to quantum materials, requires access to the structure, coupling, and dynamics on the elementary time and length scales that define the microscopic interactions in these materials. To gain the desired nanometer spatial resolution with simultaneous spectroscopic specificity we combine scanning probe microscopy with different optical, including coherent, nonlinear, and ultrafast spectroscopies. The underlying near-field interaction mediated by the atomic-force or scanning tunneling microscope tip provides the desired deep-sub wavelength nano-focusing enabling few-nm spatial resolution. I will introduce our generalization of the approach in terms of the near-field impedance matching to a quantum system based on special optical antenna-tip designs. The resulting enhanced and qualitatively new forms of light-matter interaction enable measurements of quantum dynamics in an interacting environment or to image the electromagnetic local density of states of thermal radiation. Other applications include the inter-molecular coupling and dynamics in soft-matter hetero-structures, surface plasmon interferometry as a probe of electronic structure and dynamics in graphene, and quantum phase transitions in correlated electron materials. These examples highlight the general applicability of the new near-field microscopy approach, complementing emergent X-ray and electron imaging tools, aiming towards the ultimate goal of probing matter on its most elementary spatio-temporal level.

Efficiency for preforming molecules from mixtures of light Fermi and heavy Bose atoms in optical lattices: The strong-coupling-expansion method

NASA Astrophysics Data System (ADS)

Hu, Anzi; Freericks, J. K.; Maśka, M. M.; Williams, C. J.

2011-04-01

We discuss the application of a strong-coupling expansion (perturbation theory in the hopping) for studying light-Fermi-heavy-Bose (like K40-Rb87) mixtures in optical lattices. We use the strong-coupling method to evaluate the efficiency for preforming molecules, the entropy per particle, and the thermal fluctuations. We show that within the strong interaction regime (and at high temperature), the strong-coupling expansion is an economical way to study this problem. In some cases, it remains valid even down to low temperatures. Because the computational effort is minimal, the strong-coupling approach allows us to work with much larger system sizes, where boundary effects can be eliminated, which is particularly important at higher temperatures. Since the strong-coupling approach is so efficient and accurate, it allows one to rapidly scan through parameter space in order to optimize the preforming of molecules on a lattice (by choosing the lattice depth and interspecies attraction). Based on the strong-coupling calculations, we test the thermometry scheme based on the fluctuation-dissipation theorem and find the scheme gives accurate temperature estimation even at very low temperature. We believe this approach and the calculation results will be useful in the design of the next generation of experiments and will hopefully lead to the ability to form dipolar matter in the quantum degenerate regime.

Search for Non-thermal Dark Matter in Monojet Events in Proton-Proton Collisions at $$\\sqrt{s}$$ = 13 TeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Undleeb, Sonaina

2017-01-01

This dissertation presents a search for dark matter in events with one or more jets and large missing transverse energy using proton-proton collisions at center-of-mass energy of 13 TeV. The data was collected in 2016 by the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) corresponding to an integrated luminosity of 35.9more » $$fb^{-1}$$. The results are interpreted in terms of Light Non-thermal dark matter model which explains presence of dark matter as well as baryon asymmetry in the universe. Model independent limit on narrow resonance is also obtained for monojet dominant coupling parameter space. There is no evidence for an excess of events above the background processes in the signal region, therefore cross section limits are set for different mediator masses.« less

WIMP dark matter and unitarity-conserving inflation via a gauge singlet scalar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kahlhoefer, Felix; McDonald, John, E-mail: felix.kahlhoefer@desy.de, E-mail: j.mcdonald@lancaster.ac.uk

2015-11-01

A gauge singlet scalar with non-minimal coupling to gravity can drive inflation and later freeze out to become cold dark matter. We explore this idea by revisiting inflation in the singlet direction (S-inflation) and Higgs Portal Dark Matter in light of the Higgs discovery, limits from LUX and observations by Planck. We show that large regions of parameter space remain viable, so that successful inflation is possible and the dark matter relic abundance can be reproduced. Moreover, the scalar singlet can stabilise the electroweak vacuum and at the same time overcome the problem of unitarity-violation during inflation encountered by Higgsmore » Inflation, provided the singlet is a real scalar. The 2-σ Planck upper bound on n{sub s} imposes that the singlet mass is below 2 TeV, so that almost the entire allowed parameter range can be probed by XENON1T.« less

Accretion of dark matter by stars.

PubMed

Brito, Richard; Cardoso, Vitor; Okawa, Hirotada

2015-09-11

Searches for dark matter imprints are one of the most active areas of current research. We focus here on light fields with mass m_{B}, such as axions and axionlike candidates. Using perturbative techniques and full-blown nonlinear numerical relativity methods, we show the following. (i) Dark matter can pile up in the center of stars, leading to configurations and geometries oscillating with a frequency that is a multiple of f=2.5×10^{14}(m_{B}c^{2}/eV)  Hz. These configurations are stable throughout most of the parameter space, and arise out of credible mechanisms for dark-matter capture. Stars with bosonic cores may also develop in other theories with effective mass couplings, such as (massless) scalar-tensor theories. We also show that (ii) collapse of the host star to a black hole is avoided by efficient gravitational cooling mechanisms.

Higgs portal dark matter in non-standard cosmological histories

NASA Astrophysics Data System (ADS)

Hardy, Edward

2018-06-01

A scalar particle with a relic density set by annihilations through a Higgs portal operator is a simple and minimal possibility for dark matter. However, assuming a thermal cosmological history this model is ruled out over most of parameter space by collider and direct detection constraints. We show that in theories with a non-thermal cosmological history Higgs portal dark matter is viable for a wide range of dark matter masses and values of the portal coupling, evading existing limits. In particular, we focus on the string theory motivated scenario of a period of matter domination due to a light modulus with a decay rate that is suppressed by the Planck scale. Dark matter with a mass ≲ GeV is possible without additional hidden sector states, and this can have astrophysically relevant self-interactions. We also study the signatures of such models at future direct, indirect, and collider experiments. Searches for invisible Higgs decays at the high luminosity LHC or an e + e - collider could cover a significant proportion of the parameter space for low mass dark matter, and future direct detection experiments will play a complementary role.

Surface acoustic wave regulated single photon emission from a coupled quantum dot–nanocavity system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weiß, M.; Kapfinger, S.; Wixforth, A.

2016-07-18

A coupled quantum dot–nanocavity system in the weak coupling regime of cavity-quantumelectrodynamics is dynamically tuned in and out of resonance by the coherent elastic field of a f{sub SAW} ≃ 800 MHz surface acoustic wave. When the system is brought to resonance by the sound wave, light-matter interaction is strongly increased by the Purcell effect. This leads to a precisely timed single photon emission as confirmed by the second order photon correlation function, g{sup (2)}. All relevant frequencies of our experiment are faithfully identified in the Fourier transform of g{sup (2)}, demonstrating high fidelity regulation of the stream of single photonsmore » emitted by the system.« less

High-energy vacuum birefringence and dichroism in an ultrastrong laser field

NASA Astrophysics Data System (ADS)

Meuren, Sebastian; Bragin, Sergey; Keitel, Christoph H.; di Piazza, Antonino

2017-10-01

The interaction between real photons in vacuum is a long-standing prediction of quantum electrodynamics, which has never been observed experimentally. Upcoming 10 PW laser systems like the Extreme Light Infrastructure (ELI) will provide laser pulses with unprecedented intensities. If combined with highly energetic gamma photons - obtainable via Compton backscattering from laser-wakefield accelerated electron beams - the QED critical field becomes accessible. In we have derived how a generally polarized probe photon beam is influenced by both vacuum birefringence and dichroism in a strong linearly polarized plane-wave laser field. We put forward an experimental scheme to measure these effects in the nontrivial high-energy regime, where the QED critical field is reached and the Euler-Heisenberg approximation, valid for low-frequency electromagnetic fields, breaks down. Our results suggest the feasibility of verifying/rejecting the QED prediction for vacuum birefringence/dichroism at the 3 σ confidence level on the time scale of a few days at several upcoming laser facilities. Now at Princeton University, Princeton, NJ.

Quantum nonlinear optics without photons

NASA Astrophysics Data System (ADS)

Stassi, Roberto; Macrı, Vincenzo; Kockum, Anton Frisk; Di Stefano, Omar; Miranowicz, Adam; Savasta, Salvatore; Nori, Franco

2017-08-01

Spontaneous parametric down-conversion is a well-known process in quantum nonlinear optics in which a photon incident on a nonlinear crystal spontaneously splits into two photons. Here we propose an analogous physical process where one excited atom directly transfers its excitation to a pair of spatially separated atoms with probability approaching 1. The interaction is mediated by the exchange of virtual rather than real photons. This nonlinear atomic process is coherent and reversible, so the pair of excited atoms can transfer the excitation back to the first one: the atomic analog of sum-frequency generation of light. The parameters used to investigate this process correspond to experimentally demonstrated values in ultrastrong circuit quantum electrodynamics. This approach can be extended to realize other nonlinear interatomic processes, such as four-atom mixing, and is an attractive architecture for the realization of quantum devices on a chip. We show that four-qubit mixing can efficiently implement quantum repetition codes and, thus, can be used for error-correction codes.

Ultrastrong Graphene-Copper Core-Shell Wires for High-Performance Electrical Cables.

PubMed

Kim, Sang Jin; Shin, Dong Heon; Choi, Yong Seok; Rho, Hokyun; Park, Min; Moon, Byung Joon; Kim, Youngsoo; Lee, Seuoung-Ki; Lee, Dong Su; Kim, Tae-Wook; Lee, Sang Hyun; Kim, Keun Soo; Hong, Byung Hee; Bae, Sukang

2018-03-27

Recent development in mobile electronic devices and electric vehicles requires electrical wires with reduced weight as well as enhanced stability. In addition, since electric energy is mostly generated from power plants located far from its consuming places, mechanically stronger and higher electric power transmission cables are strongly demanded. However, there has been no alternative materials that can practically replace copper materials. Here, we report a method to prepare ultrastrong graphene fibers (GFs)-Cu core-shell wires with significantly enhanced electrical and mechanical properties. The core GFs are synthesized by chemical vapor deposition, followed by electroplating of Cu shells, where the large surface area of GFs in contact with Cu maximizes the mechanical toughness of the core-shell wires. At the same time, the unique electrical and thermal characteristics of graphene allow a ∼10 times higher current density limit, providing more efficient and reliable delivery of electrical energies through the GFs-Cu wires. We believe that our results would be useful to overcome the current limit in electrical wires and cables for lightweight, energy-saving, and high-power applications.

Direct detection signatures of self-interacting dark matter with a light mediator

DOE PAGES

Nobile, Eugenio Del; Kaplinghat, Manoj; Yu, Hai-Bo

2015-10-27

Self-interacting dark matter (SIDM) is a simple and well-motivated scenario that could explain long-standing puzzles in structure formation on small scales. If the required self-interaction arises through a light mediator (with mass ~ 10 MeV) in the dark sector, this new particle must be unstable to avoid overclosing the universe. The decay of the light mediator could happen due to a weak coupling of the hidden and visible sectors, providing new signatures for direct detection experiments. The SIDM nuclear recoil spectrum is more peaked towards low energies compared to the usual case of contact interactions, because the mediator mass ismore » comparable to the momentum transfer of nuclear recoils. We show that the SIDM signal could be distinguished from that of DM particles with contact interactions by considering the time-average energy spectrum in experiments employing different target materials, or the average and modulated spectra in a single experiment. Using current limits from LUX and SuperCDMS, we also derive strong bounds on the mixing parameter between hidden and visible sector.« less

Direct detection constraints on dark photon dark matter

NASA Astrophysics Data System (ADS)

An, Haipeng; Pospelov, Maxim; Pradler, Josef; Ritz, Adam

2015-07-01

Dark matter detectors built primarily to probe elastic scattering of WIMPs on nuclei are also precise probes of light, weakly coupled, particles that may be absorbed by the detector material. In this paper, we derive constraints on the minimal model of dark matter comprised of long-lived vector states V (dark photons) in the 0.01- 100 keV mass range. The absence of an ionization signal in direct detection experiments such as XENON10 and XENON100 places a very strong constraint on the dark photon mixing angle, down to O (10-15), assuming that dark photons comprise the dominant fraction of dark matter. This sensitivity to dark photon dark matter exceeds the indirect bounds derived from stellar energy loss considerations over a significant fraction of the available mass range. We also revisit indirect constraints from V → 3 γ decay and show that limits from modifications to the cosmological ionization history are comparable to the updated limits from the diffuse γ-ray flux.

Direct detection constraints on dark photon dark matter

DOE PAGES

An, Haipeng; Pospelov, Maxim; Pradler, Josef; ...

2015-06-11

Dark matter detectors built primarily to probe elastic scattering of WIMPs on nuclei are also precise probes of light, weakly coupled, particles that may be absorbed by the detector material. In this paper, we derive constraints on the minimal model of dark matter comprised of long-lived vector states V (dark photons) in the 0.01–100KeV mass range. The absence of an ionization signal in direct detection experiments such as XENON10 and XENON100 places a very strong constraint on the dark photon mixing angle, down to Ο(10 –15), assuming that dark photons comprise the dominant fraction of dark matter. This sensitivity tomore » dark photon dark matter exceeds the indirect bounds derived from stellar energy loss considerations over a significant fraction of the available mass range. As a result, we also revisit indirect constraints from V → 3γ decay and show that limits from modifications to the cosmological ionization history are comparable to the updated limits from the diffuse γ-ray flux.« less

Highlights in light-baryon spectroscopy and searches for gluonic excitations

NASA Astrophysics Data System (ADS)

Crede, Volker

2016-01-01

The spectrum of excited hadrons - mesons and baryons - serves as an excellent probe of quantum chromodynamics (QCD), the fundamental theory of the strong interaction. The strong coupling however makes QCD challenging. It confines quarks and breaks chiral symmetry, thus providing us with the world of light hadrons. Highly-excited hadronic states are sensitive to the details of quark confinement, which is only poorly understood within QCD. This is the regime of non-perturbative QCD and it is one of the key issues in hadronic physics to identify the corresponding internal degrees of freedom and how they relate to strong coupling QCD. The quark model suggests mesons are made of a constituent quark and an antiquark and baryons consist of three such quarks. QCD predicts other forms of matter. What is the role of glue? Resonances with large gluonic components are predicted as bound states by QCD. The lightest hybrid mesons with exotic quantum numbers are estimated to have masses in the range from 1 to 2 GeV/c2 and are well in reach of current experimental programs. At Jefferson Laboratory (JLab) and other facilities worldwide, the high-energy electron and photon beams present a remarkably clean probe of hadronic matter, providing an excellent microscope for examining atomic nuclei and the strong nuclear force.

Colloquium: Excitons in atomically thin transition metal dichalcogenides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Gang; Chernikov, Alexey; Glazov, Mikhail M.

Atomically thin materials such as graphene and monolayer transition metal dichalcogenides (TMDs) exhibit remarkable physical properties resulting from their reduced dimensionality and crystal symmetry. The family of semiconducting transition metal dichalcogenides is an especially promising platform for fundamental studies of two-dimensional (2D) systems, with potential applications in optoelectronics and valleytronics due to their direct band gap in the monolayer limit and highly efficient light-matter coupling. A crystal lattice with broken inversion symmetry combined with strong spin-orbit interactions leads to a unique combination of the spin and valley degrees of freedom. In addition, the 2D character of the monolayers and weakmore » dielectric screening from the environment yield a significant enhancement of the Coulomb interaction. The resulting formation of bound electron-hole pairs, or excitons, dominates the optical and spin properties of the material. In this article, recent progress in understanding of the excitonic properties in monolayer TMDs is reviewed and future challenges are laid out. Discussed are the consequences of the strong direct and exchange Coulomb interaction, exciton light-matter coupling, and influence of finite carrier and electron-hole pair densities on the exciton properties in TMDs. Finally, the impact on valley polarization is described and the tuning of the energies and polarization observed in applied electric and magnetic fields is summarized.« less

Tailored Emission Properties of ZnTe/ZnTe:O/ZnO Core-Shell Nanowires Coupled with an Al Plasmonic Bowtie Antenna Array.

PubMed

Nie, Kui-Ying; Tu, Xuecou; Li, Jing; Chen, Xuanhu; Ren, Fang-Fang; Zhang, Guo-Gang; Kang, Lin; Gu, Shulin; Zhang, Rong; Wu, Peiheng; Zheng, Youdou; Tan, Hark Hoe; Jagadish, Chennupati; Ye, Jiandong

2018-06-14

The ability to manipulate light-matter interaction in semiconducting nanostructures is fascinating for implementing functionalities in advanced optoelectronic devices. Here, we report the tailoring of radiative emissions in a ZnTe/ZnTe:O/ZnO core-shell single nanowire coupled with a one-dimensional aluminum bowtie antenna array. The plasmonic antenna enables changes in the excitation and emission processes, leading to an obvious enhancement of near band edge emission (2.2 eV) and subgap excitonic emission (1.7 eV) bound to intermediate band states in a ZnTe/ZnTe:O/ZnO core-shell nanowire as well as surface-enhanced Raman scattering at room temperature. The increase of emission decay rate in the nanowire/antenna system, probed by time-resolved photoluminescence spectroscopy, yields an observable enhancement of quantum efficiency induced by local surface plasmon resonance. Electromagnetic simulations agree well with the experimental observations, revealing a combined effect of enhanced electric near-field intensity and the improvement of quantum efficiency in the ZnTe/ZnTe:O/ZnO nanowire/antenna system. The capability of tailoring light-matter interaction in low-efficient emitters may provide an alternative platform for designing advanced optoelectronic and sensing devices with precisely controlled response.

Colloquium: Excitons in atomically thin transition metal dichalcogenides

DOE PAGES

Wang, Gang; Chernikov, Alexey; Glazov, Mikhail M.; ...

2018-04-04

Atomically thin materials such as graphene and monolayer transition metal dichalcogenides (TMDs) exhibit remarkable physical properties resulting from their reduced dimensionality and crystal symmetry. The family of semiconducting transition metal dichalcogenides is an especially promising platform for fundamental studies of two-dimensional (2D) systems, with potential applications in optoelectronics and valleytronics due to their direct band gap in the monolayer limit and highly efficient light-matter coupling. A crystal lattice with broken inversion symmetry combined with strong spin-orbit interactions leads to a unique combination of the spin and valley degrees of freedom. In addition, the 2D character of the monolayers and weakmore » dielectric screening from the environment yield a significant enhancement of the Coulomb interaction. The resulting formation of bound electron-hole pairs, or excitons, dominates the optical and spin properties of the material. In this article, recent progress in understanding of the excitonic properties in monolayer TMDs is reviewed and future challenges are laid out. Discussed are the consequences of the strong direct and exchange Coulomb interaction, exciton light-matter coupling, and influence of finite carrier and electron-hole pair densities on the exciton properties in TMDs. Finally, the impact on valley polarization is described and the tuning of the energies and polarization observed in applied electric and magnetic fields is summarized.« less

Colloquium: Excitons in atomically thin transition metal dichalcogenides

NASA Astrophysics Data System (ADS)

Wang, Gang; Chernikov, Alexey; Glazov, Mikhail M.; Heinz, Tony F.; Marie, Xavier; Amand, Thierry; Urbaszek, Bernhard

2018-04-01

Atomically thin materials such as graphene and monolayer transition metal dichalcogenides (TMDs) exhibit remarkable physical properties resulting from their reduced dimensionality and crystal symmetry. The family of semiconducting transition metal dichalcogenides is an especially promising platform for fundamental studies of two-dimensional (2D) systems, with potential applications in optoelectronics and valleytronics due to their direct band gap in the monolayer limit and highly efficient light-matter coupling. A crystal lattice with broken inversion symmetry combined with strong spin-orbit interactions leads to a unique combination of the spin and valley degrees of freedom. In addition, the 2D character of the monolayers and weak dielectric screening from the environment yield a significant enhancement of the Coulomb interaction. The resulting formation of bound electron-hole pairs, or excitons, dominates the optical and spin properties of the material. Here recent progress in understanding of the excitonic properties in monolayer TMDs is reviewed and future challenges are laid out. Discussed are the consequences of the strong direct and exchange Coulomb interaction, exciton light-matter coupling, and influence of finite carrier and electron-hole pair densities on the exciton properties in TMDs. Finally, the impact on valley polarization is described and the tuning of the energies and polarization observed in applied electric and magnetic fields is summarized.

Ultrawide electrical tuning of light matter interaction in a high electron mobility transistor structure

PubMed Central

Pal, Shovon; Nong, Hanond; Markmann, Sergej; Kukharchyk, Nadezhda; Valentin, Sascha R.; Scholz, Sven; Ludwig, Arne; Bock, Claudia; Kunze, Ulrich; Wieck, Andreas D.; Jukam, Nathan

2015-01-01

The interaction between intersubband resonances (ISRs) and metamaterial microcavities constitutes a strongly coupled system where new resonances form that depend on the coupling strength. Here we present experimental evidence of strong coupling between the cavity resonance of a terahertz metamaterial and the ISR in a high electron mobility transistor (HEMT) structure. The device is electrically switched from an uncoupled to a strongly coupled regime by tuning the ISR with epitaxially grown transparent gate. The asymmetric potential in the HEMT structure enables ultrawide electrical tuning of ISR, which is an order of magnitude higher as compared to an equivalent square well. For a single heterojunction with a triangular confinement, we achieve an avoided splitting of 0.52 THz, which is a significant fraction of the bare intersubband resonance at 2 THz. PMID:26578287

Couplings between the ρ and D and D * mesons

DOE PAGES

El-Bennich, Bruno; Paracha, M. Ali; Roberts, Craig D.; ...

2017-02-27

In this paper, we compute couplings between the ρ-meson and D and D* mesons—D(*)ρD(*)—that are relevant to phenomenological meson-exchange models used to analyze nucleon–D-meson scattering and explore the possibility of exotic charmed nuclei. Our framework is built from elements constrained by Dyson-Schwinger equation studies in QCD, and therefore expresses a simultaneous description of light- and heavy-quarks and the states they constitute. We find that all interactions, including the three independent D*ρD* couplings, differ markedly amongst themselves in strength and also in range, as measured by their evolution with ρ-meson virtuality. As a consequence, it appears that one should be cautiousmore » in using a single coupling strength or parametrization for the study of interactions between D(*) mesons and matter.« less

Coupling of individual quantum emitters to channel plasmons.

PubMed

Bermúdez-Ureña, Esteban; Gonzalez-Ballestero, Carlos; Geiselmann, Michael; Marty, Renaud; Radko, Ilya P; Holmgaard, Tobias; Alaverdyan, Yury; Moreno, Esteban; García-Vidal, Francisco J; Bozhevolnyi, Sergey I; Quidant, Romain

2015-08-07

Efficient light-matter interaction lies at the heart of many emerging technologies that seek on-chip integration of solid-state photonic systems. Plasmonic waveguides, which guide the radiation in the form of strongly confined surface plasmon-polariton modes, represent a promising solution to manipulate single photons in coplanar architectures with unprecedented small footprints. Here we demonstrate coupling of the emission from a single quantum emitter to the channel plasmon polaritons supported by a V-groove plasmonic waveguide. Extensive theoretical simulations enable us to determine the position and orientation of the quantum emitter for optimum coupling. Concomitantly with these predictions, we demonstrate experimentally that 42% of a single nitrogen-vacancy centre emission efficiently couples into the supported modes of the V-groove. This work paves the way towards practical realization of efficient and long distance transfer of energy for integrated solid-state quantum systems.

Couplings between the ρ and D and D * mesons

DOE Office of Scientific and Technical Information (OSTI.GOV)

El-Bennich, Bruno; Paracha, M. Ali; Roberts, Craig D.

In this paper, we compute couplings between the ρ-meson and D and D* mesons—D(*)ρD(*)—that are relevant to phenomenological meson-exchange models used to analyze nucleon–D-meson scattering and explore the possibility of exotic charmed nuclei. Our framework is built from elements constrained by Dyson-Schwinger equation studies in QCD, and therefore expresses a simultaneous description of light- and heavy-quarks and the states they constitute. We find that all interactions, including the three independent D*ρD* couplings, differ markedly amongst themselves in strength and also in range, as measured by their evolution with ρ-meson virtuality. As a consequence, it appears that one should be cautiousmore » in using a single coupling strength or parametrization for the study of interactions between D(*) mesons and matter.« less

Characterization of plasmonic hole arrays as transparent electrical contacts for organic photovoltaics using high-brightness Fourier transform methods

DOE PAGES

Camino, Fernando E.; Nam, Chang-Yong; Pang, Yutong T.; ...

2014-05-15

Here we present a methodology for probing light-matter interactions in prototype photovoltaic devices consisting of an organic semiconductor active layer with a semitransparent metal electrical contact exhibiting surface plasmon-based enhanced optical transmission. We achieve high-spectral irradiance in a spot size of less than 100 μm using a high-brightness laser-driven light source and appropriate coupling optics. Spatially resolved Fourier transform photocurrent spectroscopy in the visible and near-infrared spectral regions allows us to measure external quantum efficiency with high sensitivity in small-area devices (<1 mm 2). Lastly, this allows for rapid fabrication of variable-pitch sub-wavelength hole arrays in metal films for usemore » as transparent electrical contacts, and evaluation of the evanescent and propagating mode coupling to resonances in the active layer.« less

Near unity ultraviolet absorption in graphene without patterning

NASA Astrophysics Data System (ADS)

Zhu, Jinfeng; Yan, Shuang; Feng, Naixing; Ye, Longfang; Ou, Jun-Yu; Liu, Qing Huo

2018-04-01

Enhancing the light-matter interaction of graphene is an important issue for related photonic devices and applications. In view of its potential ultraviolet applications, we aim to achieve extremely high ultraviolet absorption in graphene without any nanostructure or microstructure patterning. By manipulating the polarization and angle of incident light, the ultraviolet power can be sufficiently coupled to the optical dissipation of graphene based on single-channel coherent perfect absorption in an optimized multilayered thin film structure. The ultraviolet absorbance ratios of single and four atomic graphene layers are enhanced up to 71.4% and 92.2%, respectively. Our research provides a simple and efficient scheme to trap ultraviolet light for developing promising photonic and optoelectronic devices based on graphene and potentially other 2D materials.

Design of dual-diameter nanoholes for efficient solar-light harvesting

PubMed Central

2014-01-01

A dual-diameter nanohole (DNH) photovoltaic system is proposed, where a top (bottom) layer with large (small) nanoholes is used to improve the absorption for the short-wavelength (long-wavelength) solar incidence, leading to a broadband light absorption enhancement. Through three-dimensional finite-element simulation, the core device parameters, including the lattice constant, nanohole diameters, and nanohole depths, are engineered in order to realize the best light-matter coupling between nanostructured silicon and solar spectrum. The designed bare DNH system exhibits an outstanding absorption capability with a photocurrent density (under perfect internal quantum process) predicted to be 27.93 mA/cm2, which is 17.39%, 26.17%, and over 100% higher than the best single-nanohole (SNH) system, SNH system with an identical Si volume, and equivalent planar configuration, respectively. Considering the fabrication feasibility, a modified DNH system with an anti-reflection coating and back silver reflector is examined by simulating both optical absorption and carrier transport in a coupled way in frequency and three-dimensional spatial domains, achieving a light-conversion efficiency of 13.72%. PACS 85.60.-q; Optoelectronic device; 84.60.Jt; Photovoltaic conversion PMID:25258605

Search for light scalar dark matter with atomic gravitational wave detectors

NASA Astrophysics Data System (ADS)

Arvanitaki, Asimina; Graham, Peter W.; Hogan, Jason M.; Rajendran, Surjeet; Van Tilburg, Ken

2018-04-01

We show that gravitational wave detectors based on a type of atom interferometry are sensitive to ultralight scalar dark matter. Such dark matter can cause temporal oscillations in fundamental constants with a frequency set by the dark matter mass and amplitude determined by the local dark matter density. The result is a modulation of atomic transition energies. We point out a new time-domain signature of this effect in a type of gravitational wave detector that compares two spatially separated atom interferometers referenced by a common laser. Such a detector can improve on current searches for electron-mass or electric-charge modulus dark matter by up to 10 orders of magnitude in coupling, in a frequency band complementary to that of other proposals. It demonstrates that this class of atomic sensors is qualitatively different from other gravitational wave detectors, including those based on laser interferometry. By using atomic-clock-like interferometers, laser noise is mitigated with only a single baseline. These atomic sensors can thus detect scalar signals in addition to tensor signals.

Role of magnetic and diamagnetic interactions in molecular optics and scattering

NASA Astrophysics Data System (ADS)

Forbes, Kayn A.

2018-05-01

This paper aims to explicitly clarify the role and interpretation of diamagnetic interactions between molecules and light in quantum electrodynamics. In contrast to their electric and magnetic counterparts, the diamagnetic couplings between light and matter have received relatively little interest in the field of molecular optics. This intriguing disregard of an interaction term is puzzling. The diamagnetic couplings possess unique physical properties that warrant their inclusion in any multiphoton process, and the lack of gauge invariance for paramagnetic and diamagnetic susceptibilities necessitates their inclusion. Their role and importance within nonrelativistic molecular quantum electrodynamics in the Coulomb gauge is illuminated, and it is highlighted how for any multiphoton process their inclusion should be implicit. As an indicative example of the theory presented, the diamagnetic contributions to both forward and nonforward Rayleigh scattering are derived and put into context alongside the electric and magnetic molecular responses. The work represents clarification of diamagnetic couplings in molecular quantum electrodynamics, which subsequently should proffer the study of diamagnetic interactions in molecular optics due to their unique physical attributes and necessary inclusion in multiphoton processes.

D-brane disformal coupling and thermal dark matter

NASA Astrophysics Data System (ADS)

Dutta, Bhaskar; Jimenez, Esteban; Zavala, Ivonne

2017-11-01

Conformal and disformal couplings between a scalar field and matter occur naturally in general scalar-tensor theories. In D-brane models of cosmology and particle physics, these couplings originate from the D-brane action describing the dynamics of its transverse (the scalar) and longitudinal (matter) fluctuations, which are thus coupled. During the post-inflationary regime and before the onset of big bang nucleosynthesis (BBN), these couplings can modify the expansion rate felt by matter, changing the predictions for the thermal relic abundance of dark matter particles and thus the annihilation rate required to satisfy the dark matter content today. We study the D-brane-like conformal and disformal couplings effect on the expansion rate of the Universe prior to BBN and its impact on the dark matter relic abundance and annihilation rate. For a purely disformal coupling, the expansion rate is always enhanced with respect to the standard one. This gives rise to larger cross sections when compared to the standard thermal prediction for a range of dark matter masses, which will be probed by future experiments. In a D-brane-like scenario, the scale at which the expansion rate enhancement occurs depends on the string coupling and the string scale.

Optical Control of Mechanical Mode-Coupling within a MoS2 Resonator in the Strong-Coupling Regime.

PubMed

Liu, Chang-Hua; Kim, In Soo; Lauhon, Lincoln J

2015-10-14

Two-dimensional (2-D) materials including graphene and transition metal dichalcogenides (TMDs) are an exciting platform for ultrasensitive force and displacement detection in which the strong light-matter coupling is exploited in the optical control of nanomechanical motion. Here we report the optical excitation and displacement detection of a ∼ 3 nm thick MoS2 resonator in the strong-coupling regime, which has not previously been achieved in 2-D materials. Mechanical mode frequencies can be tuned by more than 12% by optical heating, and they exhibit avoided crossings indicative of strong intermode coupling. When the membrane is optically excited at the frequency difference between vibrational modes, normal mode splitting is observed, and the intermode energy exchange rate exceeds the mode decay rate by a factor of 15. Finite element and analytical modeling quantifies the extent of mode softening necessary to control intermode energy exchange in the strong coupling regime.

Transport of Light Ions in Matter

NASA Technical Reports Server (NTRS)

Wilson, J. W.; Cucinotta, F. A.; Tai, H.; Shinn, J. L.; Chun, S. Y.; Tripathi, R. K.; Sihver, L.

1998-01-01

A recent set of light ion experiments are analyzed using the Green's function method of solving the Boltzmann equation for ions of high charge and energy (the GRNTRN transport code) and the NUCFRG2 fragmentation database generator code. Although the NUCFRG2 code reasonably represents the fragmentation of heavy ions, the effects of light ion fragmentation requires a more detailed nuclear model including shell structure and short range correlations appearing as tightly bound clusters in the light ion nucleus. The most recent NTJCFRG2 code is augmented with a quasielastic alpha knockout model and semiempirical adjustments (up to 30 percent in charge removal) in the fragmentation process allowing reasonable agreement with the experiments to be obtained. A final resolution of the appropriate cross sections must await the full development of a coupled channel reaction model in which shell structure and clustering can be accurately evaluated.

Theory and modelling of light-matter interactions in photonic crystal cavity systems coupled to quantum dot ensembles

NASA Astrophysics Data System (ADS)

Cartar, William K.

Photonic crystal microcavity quantum dot lasers show promise as high quality-factor, low threshold lasers, that can be integrated on-chip, with tunable room temperature opera- tions. However, such semiconductor microcavity lasers are notoriously difficult to model in a self-consistent way and are primarily modelled by simplified rate equation approxima- tions, typically fit to experimental data, which limits investigations of their optimization and fundamental light-matter interaction processes. Moreover, simple cavity mode optical theory and rate equations have recently been shown to fail in explaining lasing threshold trends in triangular lattice photonic crystal cavities as a function of cavity size, and the potential impact of fabrication disorder is not well understood. In this thesis, we develop a simple but powerful numerical scheme for modelling the quantum dot active layer used for lasing in these photonic crystal cavity structures, as an ensemble of randomly posi- tioned artificial two-level atoms. Each two-level atom is defined by optical Bloch equations solved by a quantum master equation that includes phenomenological pure dephasing and an incoherent pump rate that effectively models a multi-level gain system. Light-matter in- teractions of both passive and lasing structures are analyzed using simulation defined tools and post-simulation Green function techniques. We implement an active layer ensemble of up to 24,000 statistically unique quantum dots in photonic crystal cavity simulations, using a self-consistent finite-difference time-domain method. This method has the distinct advantage of capturing effects such as dipole-dipole coupling and radiative decay, without the need for any phenomenological terms, since the time-domain solution self-consistently captures these effects. Our analysis demonstrates a powerful ability to connect with recent experimental trends, while remaining completely general in its set-up; for example, we do not invoke common approximations such as the rotating-wave or slowly-varying envelope approximations, and solve dynamics with zero a priori knowledge.

An on-chip colloidal magneto-optical grating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prikockis, M.; Wijesinghe, H.; Chen, A.

2016-04-18

Interacting nano- and micro-particles provide opportunities to create a wide range of useful colloidal and soft matter constructs. In this letter, we examine interacting superparamagnetic polymeric particles residing on designed permalloy (Ni{sub 0.8} Fe{sub 0.2}) shapes that are subject to weak time-orbiting magnetic fields. The precessing field and magnetic barriers that ensue along the outer perimeter of the shapes allow for containment concurrent with independent field-tunable ordering of the dipole-coupled particles. These remotely activated arrays with inter-particle spacing comparable to the wavelength of light yield microscopic on-chip surface gratings for beam steering and magnetically regulated light diffraction applications.

One-dimensional surface-plasmon gratings for the excitation of intersubband polaritons in suspended membranes

NASA Astrophysics Data System (ADS)

Degl'Innocenti, R.; Zanotto, S.; Tredicucci, A.; Biasiol, G.; Sorba, L.

2011-12-01

We present the observation of the strong light-matter coupling regime between intersubband transitions of semiconductor quantum wells and the plasmonic-like resonances of a one dimensional metallic grating. Polariton spectra have been recorded in transmission employing a suspended membrane sample and are consistent with theoretical calculations. This arrangement, avoiding the complexity of dispersive substrate, is particularly attractive for the development of time-resolved pump-probe experiments.

Constraints on Resonant Dark Matter Annihilation

NASA Astrophysics Data System (ADS)

Backovic, Mihailo

Resonant dark matter annihilation drew much attention in the light of recent measurements of charged cosmic ray fluxes. Interpreting the anomalous signal in the positron fraction as a sign of dark matter annihilation in the galactic halo requires cross sections orders of magnitudes higher than the estimates coming from thermal relic abundance. Resonant dark matter annihilation provides a mechanism to bridge the apparent contradiction between thermal relic abundance and the positron data measured by PAMELA and FERMI satellites. In this thesis, we analyze a class of models which allow for dark matter to annihilate through an s-channel resonance. Our analysis takes into account constraints from thermal relic abundance and the recent measurements of charged lepton cosmic ray fluxes, first separately and then simultaneously. Consistency of resonant dark matter annihilation models with thermal relic abundance as measured by WMAP serves to construct a relationship between the full set of masses, couplings and widths involved. Extensive numerical analysis of the full four dimensional parameter space is summarized by simple analytic approximations. The expressions are robust enough to be generalized to models including additional annihilation channels. We provide a separate treatment of resonant annihilation of dark matter in the galac- tic halo. We find model-independent upper limits on halo dark matter annihilation rates and show that the most efficient annihilation mechanism involves s-channel resonances. Widths that are large compared to the energy spread in the galactic halo are capable of saturating unitarity bounds without much difficulty. Partial wave unitarity prevents the so called Sommerfeld factors from producing large changes in cross sections. In addition, the approximations made in Sommerfeld factors break down in the kinematic regions where large cross section enhancements are often cited. Simultaneous constraints from thermal relic abundance and halo annihilation serve to produce new limits on dark matter masses and couplings. Past considerations of only a part of the resonant annihilation parameter set to motivate large annihilation cross section enhancements in the halo while maintaining correct relic abundance are generally incomplete. Taking into account only the resonance mass and width to show that large cross section enhancements are possible does not in principle guarantee that the enhancement will be achieved. We extend the calculation to include the full resonant parameter set. As a result, we obtain new limits on dark matter masses and couplings.

Weak Lensing Peaks in Simulated Light-Cones: Investigating the Coupling between Dark Matter and Dark Energy

NASA Astrophysics Data System (ADS)

Giocoli, Carlo; Moscardini, Lauro; Baldi, Marco; Meneghetti, Massimo; Metcalf, Robert B.

2018-05-01

In this paper, we study the statistical properties of weak lensing peaks in light-cones generated from cosmological simulations. In order to assess the prospects of such observable as a cosmological probe, we consider simulations that include interacting Dark Energy (hereafter DE) models with coupling term between DE and Dark Matter. Cosmological models that produce a larger population of massive clusters have more numerous high signal-to-noise peaks; among models with comparable numbers of clusters those with more concentrated haloes produce more peaks. The most extreme model under investigation shows a difference in peak counts of about 20% with respect to the reference ΛCDM model. We find that peak statistics can be used to distinguish a coupling DE model from a reference one with the same power spectrum normalisation. The differences in the expansion history and the growth rate of structure formation are reflected in their halo counts, non-linear scale features and, through them, in the properties of the lensing peaks. For a source redshift distribution consistent with the expectations of future space-based wide field surveys, we find that typically seventy percent of the cluster population contributes to weak-lensing peaks with signal-to-noise ratios larger than two, and that the fraction of clusters in peaks approaches one-hundred percent for haloes with redshift z ≤ 0.5. Our analysis demonstrates that peak statistics are an important tool for disentangling DE models by accurately tracing the structure formation processes as a function of the cosmic time.

Evidence for a Quantum-to-Classical Transition in a Pair of Coupled Quantum Rotors

NASA Astrophysics Data System (ADS)

Gadway, Bryce; Reeves, Jeremy; Krinner, Ludwig; Schneble, Dominik

2013-05-01

The understanding of how classical dynamics can emerge in closed quantum systems is a problem of fundamental importance. Remarkably, while classical behavior usually arises from coupling to thermal fluctuations or random spectral noise, it may also be an innate property of certain isolated, periodically driven quantum systems. Here, we experimentally realize the simplest such system, consisting of two coupled, kicked quantum rotors, by subjecting a coherent atomic matter wave to two periodically pulsed, incommensurate optical lattices. Momentum transport in this system is found to be radically different from that in a single kicked rotor, with a breakdown of dynamical localization and the emergence of classical diffusion. Our observation, which confirms a long-standing prediction for many-dimensional quantum-chaotic systems, sheds new light on the quantum-classical correspondence.

Organic matters removal from landfill leachate by immobilized Phanerochaete chrysosporium loaded with graphitic carbon nitride under visible light irradiation.

PubMed

Hu, Liang; Liu, Yutang; Zeng, Guangming; Chen, Guiqiu; Wan, Jia; Zeng, Yunxiong; Wang, Longlu; Wu, Haipeng; Xu, Piao; Zhang, Chen; Cheng, Min; Hu, Tianjue

2017-10-01

This study investigated the technical applicability of a combination of Phanerochaete chrysosporium (P. chrysosporium) with photocatalyst graphitic carbon nitride (g-C 3 N 4 ) for organic matters removal from landfill leachate under visible light irradiation. Photocatalyst g-C 3 N 4 was well immobilized on the hyphae surface of P. chrysosporium by calcium alginate. The typical absorption edge in visible light region for g-C 3 N 4 was at about 460 nm, and the optical absorption bandgap of g-C 3 N 4 was estimated to be 2.70 eV, demonstrating the great photoresponsive ability of g-C 3 N 4 . An optimized g-C 3 N 4 content of 0.10 g in immobilized P. chrysosporium and an optimized immobilized P. chrysosporium dosage of 1.0 g were suitable for organic matters removal. The removal efficiency of total organic carbon (TOC) reached 74.99% in 72 h with the initial TOC concentration of 100 mg L -1 . In addition, the gas chromatography coupled with mass spectrometry (GC-MS) measurements showed that immobilized P. chrysosporium presented an outstanding removal performance for almost all organic compounds in landfill leachate, especially for the volatile fatty acids and long-chain hydrocarbons. The overall results indicate that the combination P. chrysosporium with photocatalyst g-C 3 N 4 for organic matters removal from landfill leachate may provide a more comprehensive potential for the landfill leachate treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Non-canonical distribution and non-equilibrium transport beyond weak system-bath coupling regime: A polaron transformation approach

NASA Astrophysics Data System (ADS)

Xu, Dazhi; Cao, Jianshu

2016-08-01

The concept of polaron, emerged from condense matter physics, describes the dynamical interaction of moving particle with its surrounding bosonic modes. This concept has been developed into a useful method to treat open quantum systems with a complete range of system-bath coupling strength. Especially, the polaron transformation approach shows its validity in the intermediate coupling regime, in which the Redfield equation or Fermi's golden rule will fail. In the polaron frame, the equilibrium distribution carried out by perturbative expansion presents a deviation from the canonical distribution, which is beyond the usual weak coupling assumption in thermodynamics. A polaron transformed Redfield equation (PTRE) not only reproduces the dissipative quantum dynamics but also provides an accurate and efficient way to calculate the non-equilibrium steady states. Applications of the PTRE approach to problems such as exciton diffusion, heat transport and light-harvesting energy transfer are presented.

Baryogenesis in nonminimally coupled f (R ) theories

NASA Astrophysics Data System (ADS)

Ramos, M. P. L. P.; Páramos, J.

2017-11-01

We generalize the mechanism for gravitational baryogensis in the context of f (R ) theories of gravity, including a nonminimal coupling between curvature and matter. In these models, the baryon asymmetry is generated through an effective coupling between the Ricci scalar curvature and the net baryon current that dynamically breaks Charge conjugation, parity and time reversal (C P T ) invariance. We study the combinations of characteristic mass scales and exponents for both nontrivial functions present in the modified action functional and establish the allowed region for these parameters: we find that very small deviations from general relativity are consistent with the observed baryon asymmetry and lead to temperatures compatible with the subsequent formation of the primordial abundances of light elements. In particular, we show the viability of a power-law nonminimal coupling function f2(R )˜Rn with 0

Quantum optics in a high impedance environment

NASA Astrophysics Data System (ADS)

Puertas, Javier; Gheeraert, Nicolas; Krupko, Yuriy; Dassonneville, Remy; Planat, Luca; Foroughui, Farshad; Naud, Cecile; Guichard, Wiebke; Buisson, Olivier; Florens, Serge; Roch, Nicolas; Snyman, Izak

Understanding light matter interaction remains a key topic in fundamental physics. Its strength is imposed by the fine structure constant, α. For most atomic and molecular systems α =e2/ℏc 4 πɛo = 1 / 137 << 1 , giving weak interactions. When dealing with superconducting artificial atoms, α is either proportional to 1 /Zc (magnetic coupling) or Zc (electric coupling), where Zc is the characteristic impedance of the environment. Recent experiments followed the first approach, coupling a flux qubit to a low impedance environment, demonstrating strong interaction (α 1). In our work, we reached the large α regime, following a complementary approach: we couple electrically a transmon qubit to an array of 5000 SQUIDs. This metamaterial provides high characteristic impedance ( 3 kΩ), in-situ flux tunability and full control over its dispersion relation. In this new regime, all usual approximations break down and new phenomena such as frequency conversion at the single photon level are expected.

Phonon-mediated repulsion, sharp transitions and (quasi)self-trapping in the extended Peierls-Hubbard model

NASA Astrophysics Data System (ADS)

Sous, John; Chakraborty, Monodeep; Krems, Roman; Berciu, Mona

We study two identical fermions, or two hard-core bosons, in an infinite chain and coupled to phonons by interactions that modulate their hopping as described by the Peierls/Su-Schrieffer- Heeger (SSH) model. We show that exchange of phonons generates effective nearest-neighbor repulsion between particles and also gives rise to interactions that move the pair as a whole. The two-polaron phase diagram exhibits two sharp transitions, leading to light dimers at strong coupling and the flattening of the dimer dispersion at some critical values of the parameters. This dimer (quasi)self-trapping occurs at coupling strengths where single polarons are mobile. This illustrates that, depending on the strength of the phonon-mediated interactions, the coupling to phonons may completely suppress or strongly enhance quantum transport of correlated particles. NSERC, Stewart Blusson Quantum Matter Institute.

Chameleon gravity, electrostatics, and kinematics in the outer galaxy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pourhasan, R.; Mann, R.B.; Afshordi, N.

2011-12-01

Light scalar fields are expected to arise in theories of high energy physics (such as string theory), and find phenomenological motivations in dark energy, dark matter, or neutrino physics. However, the coupling of light scalar fields to ordinary (or dark) matter is strongly constrained from laboratory, solar system, and astrophysical tests of the fifth force. One way to evade these constraints in dense environments is through the chameleon mechanism, where the field's mass steeply increases with ambient density. Consequently, the chameleonic force is only sourced by a thin shell near the surface of dense objects, which significantly reduces its magnitude.more » In this paper, we argue that thin-shell conditions are equivalent to ''conducting'' boundary conditions in electrostatics. As an application, we use the analogue of the method of images to calculate the back-reaction (or self-force) of an object around a spherical gravitational source. Using this method, we can explicitly compute the violation of the equivalence principle in the outskirts of galactic haloes (assuming an NFW dark matter profile): Intermediate mass satellites can be slower than their larger/smaller counterparts by as much as 10% close to a thin shell.« less

On the uniqueness of the non-minimal matter coupling in massive gravity and bigravity

DOE PAGES

Huang, Qing-Guo; Ribeiro, Raquel H.; Xing, Yu-Hang; ...

2015-07-03

In de Rham–Gabadadze–Tolley (dRGT) massive gravity and bi-gravity, a non-minimal matter coupling involving both metrics generically reintroduces the Boulware–Deser (BD) ghost. A non-minimal matter coupling via a simple, yet specific composite metric has been proposed, which eliminates the BD ghost below the strong coupling scale. Working explicitly in the metric formulation and for arbitrary spacetime dimensions, we show that this composite metric is the unique consistent non-minimal matter coupling below the strong coupling scale, which emerges out of two diagnostics, namely, the absence of Ostrogradski ghosts in the decoupling limit and the absence of the BD ghost from matter quantummore » loop corrections.« less

Imaging exciton–polariton transport in MoSe2 waveguides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, F.; Luan, Y.; Scott, M. E.

The exciton polariton (EP), a half-light and half-matter quasiparticle, is potentially an important element for future photonic and quantum technologies1-4. It provides both strong light-matter interactions and long-distance propagation that is necessary for applications associated with energy or information transfer. Recently, strongly-coupled cavity EPs at room temperature have been demonstrated in van der Waals (vdW) materials due to their strongly-bound excitons5-9. Here we report a nano-optical imaging study of waveguide EPs in MoSe2, a prototypical vdW semiconductor. The measured propagation length of the EPs is sensitive to the excitation photon energy and reaches over 12 μm. The polariton wavelength canmore » be conveniently altered from 600 nm down to 300 nm by controlling the waveguide thickness. Furthermore, we found an intriguing back-bending polariton dispersion close to the exciton resonance. The observed EPs in vdW semiconductors could be useful in future nanophotonic circuits operating in the near-infrared to visible spectral regions.« less

Imaging exciton–polariton transport in MoSe2 waveguides

DOE PAGES

Hu, F.; Luan, Y.; Scott, M. E.; ...

2017-05-08

The exciton polariton (EP), a half-light and half-matter quasiparticle, is potentially an important element for future photonic and quantum technologies1-4. It provides both strong light-matter interactions and long-distance propagation that is necessary for applications associated with energy or information transfer. Recently, strongly-coupled cavity EPs at room temperature have been demonstrated in van der Waals (vdW) materials due to their strongly-bound excitons5-9. Here we report a nano-optical imaging study of waveguide EPs in MoSe2, a prototypical vdW semiconductor. The measured propagation length of the EPs is sensitive to the excitation photon energy and reaches over 12 μm. The polariton wavelength canmore » be conveniently altered from 600 nm down to 300 nm by controlling the waveguide thickness. Furthermore, we found an intriguing back-bending polariton dispersion close to the exciton resonance. The observed EPs in vdW semiconductors could be useful in future nanophotonic circuits operating in the near-infrared to visible spectral regions.« less

Nanoscale Imaging of Light-Matter Coupling Inside Metal-Coated Cavities with a Pulsed Electron Beam.

PubMed

Moerland, Robert J; Weppelman, I Gerward C; Scotuzzi, Marijke; Hoogenboom, Jacob P

2018-05-02

Many applications in (quantum) nanophotonics rely on controlling light-matter interaction through strong, nanoscale modification of the local density of states (LDOS). All-optical techniques probing emission dynamics in active media are commonly used to measure the LDOS and benchmark experimental performance against theoretical predictions. However, metal coatings needed to obtain strong LDOS modifications in, for instance, nanocavities, are incompatible with all-optical characterization. So far, no reliable method exists to validate theoretical predictions. Here, we use subnanosecond pulses of focused electrons to penetrate the metal and excite a buried active medium at precisely defined locations inside subwavelength resonant nanocavities. We reveal the spatial layout of the spontaneous-emission decay dynamics inside the cavities with deep-subwavelength detail, directly mapping the LDOS. We show that emission enhancement converts to inhibition despite an increased number of modes, emphasizing the critical role of optimal emitter location. Our approach yields fundamental insight in dynamics at deep-subwavelength scales for a wide range of nano-optical systems.

Light scalar dark matter at neutrino oscillation experiments

NASA Astrophysics Data System (ADS)

Liao, Jiajun; Marfatia, Danny; Whisnant, Kerry

2018-04-01

Couplings between light scalar dark matter (DM) and neutrinos induce a perturbation to the neutrino mass matrix. If the DM oscillation period is smaller than ten minutes (or equivalently, the DM particle is heavier than 0.69×10-17 eV), the fast-averaging over an oscillation cycle leads to a modification of the measured oscillation parameters. We present a specific μ - τ symmetric model in which the measured value of θ 13 is entirely generated by the DM interaction, and which reproduces the other measured oscillation parameters. For a scalar DM particle lighter than 10-15 eV, adiabatic solar neutrino propagation is maintained. A suppression of the sensitivity to CP violation at long baseline neutrino experiments is predicted in this model. We find that DUNE cannot exclude the DM scenario at more than 3 σ C.L. for bimaximal, tribimaximal and hexagonal mixing, while JUNO can rule it out at more than 6 σ C.L. by precisely measuring both θ 12 and θ 13.

High-Q/V Monolithic Diamond Microdisks Fabricated with Quasi-isotropic Etching.

PubMed

Khanaliloo, Behzad; Mitchell, Matthew; Hryciw, Aaron C; Barclay, Paul E

2015-08-12

Optical microcavities enhance light-matter interactions and are essential for many experiments in solid state quantum optics, optomechanics, and nonlinear optics. Single crystal diamond microcavities are particularly sought after for applications involving diamond quantum emitters, such as nitrogen vacancy centers, and for experiments that benefit from diamond's excellent optical and mechanical properties. Light-matter coupling rates in experiments involving microcavities typically scale with Q/V, where Q and V are the microcavity quality-factor and mode-volume, respectively. Here we demonstrate that microdisk whispering gallery mode cavities with high Q/V can be fabricated directly from bulk single crystal diamond. By using a quasi-isotropic oxygen plasma to etch along diamond crystal planes and undercut passivated diamond structures, we create monolithic diamond microdisks. Fiber taper based measurements show that these devices support TE- and TM-like optical modes with Q > 1.1 × 10(5) and V < 11(λ/n) (3) at a wavelength of 1.5 μm.

New Models and Methods for the Electroweak Scale

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carpenter, Linda

2017-09-26

This is the Final Technical Report to the US Department of Energy for grant DE-SC0013529, New Models and Methods for the Electroweak Scale, covering the time period April 1, 2015 to March 31, 2017. The goal of this project was to maximize the understanding of fundamental weak scale physics in light of current experiments, mainly the ongoing run of the Large Hadron Collider and the space based satellite experiements searching for signals Dark Matter annihilation or decay. This research program focused on the phenomenology of supersymmetry, Higgs physics, and Dark Matter. The properties of the Higgs boson are currently beingmore » measured by the Large Hadron collider, and could be a sensitive window into new physics at the weak scale. Supersymmetry is the leading theoretical candidate to explain the natural nessof the electroweak theory, however new model space must be explored as the Large Hadron collider has disfavored much minimal model parameter space. In addition the nature of Dark Matter, the mysterious particle that makes up 25% of the mass of the universe is still unknown. This project sought to address measurements of the Higgs boson couplings to the Standard Model particles, new LHC discovery scenarios for supersymmetric particles, and new measurements of Dark Matter interactions with the Standard Model both in collider production and annihilation in space. Accomplishments include new creating tools for analyses of Dark Matter models in Dark Matter which annihilates into multiple Standard Model particles, including new visualizations of bounds for models with various Dark Matter branching ratios; benchmark studies for new discovery scenarios of Dark Matter at the Large Hardon Collider for Higgs-Dark Matter and gauge boson-Dark Matter interactions; New target analyses to detect direct decays of the Higgs boson into challenging final states like pairs of light jets, and new phenomenological analysis of non-minimal supersymmetric models, namely the set of Dirac Gaugino Models.« less

Dynamic generation of light states with discrete symmetries

NASA Astrophysics Data System (ADS)

Cordero, S.; Nahmad-Achar, E.; Castaños, O.; López-Peña, R.

2018-01-01

A dynamic procedure is established within the generalized Tavis-Cummings model to generate light states with discrete point symmetries, given by the cyclic group Cn. We consider arbitrary dipolar coupling strengths of the atoms with a one-mode electromagnetic field in a cavity. The method uses mainly the matter-field entanglement properties of the system, which can be extended to any number of three-level atoms. An initial state constituted by the superposition of two states with definite total excitation numbers, |ψ〉 M1,and |ψ〉 M 2, is considered. It can be generated by the proper selection of the time of flight of an atom passing through the cavity. We demonstrate that the resulting Husimi function of the light is invariant under cyclic point transformations of order n =| M1-M2| .

Inflatable Dark Matter

DOE PAGES

Davoudiasl, Hooman; Hooper, Dan; McDermott, Samuel D.

2016-01-22

We describe a general scenario, dubbed “Inflatable Dark Matter”, in which the density of dark matter particles can be reduced through a short period of late-time inflation in the early universe. The overproduction of dark matter that is predicted within many otherwise well-motivated models of new physics can be elegantly remedied within this context, without the need to tune underlying parameters or to appeal to anthropic considerations. Thermal relics that would otherwise be disfavored can easily be accommodated within this class of scenarios, including dark matter candidates that are very heavy or very light. Furthermore, the non-thermal abundance of GUTmore » or Planck scale axions can be brought to acceptable levels, without invoking anthropic tuning of initial conditions. Additionally, a period of late-time inflation could have occurred over a wide range of scales from ~ MeV to the weak scale or above, and could have been triggered by physics within a hidden sector, with small but not necessarily negligible couplings to the Standard Model.« less

Probing velocity dependent self-interacting dark matter with neutrino telescopes

NASA Astrophysics Data System (ADS)

Robertson, Denis S.; Albuquerque, Ivone F. M.

2018-02-01

Self-interacting dark matter models constitute an attractive solution to problems in structure formation on small scales. A simple realization of these models considers the dark force mediated by a light particle which can couple to the Standard Model through mixings with the photon or the Z boson. Within this scenario we investigate the sensitivity of the IceCube-DeepCore and PINGU neutrino telescopes to the associated muon neutrino flux produced by dark matter annihilations in the Sun. Despite the model's simplicity, several effects naturally appear: momentum suppressed capture by nuclei, velocity dependent dark matter self-capture, Sommerfeld enhanced annihilation, as well as the enhancement on the neutrino flux due to mediator late decays. Taking all these effects into account, we find that most of the model relevant parameter space can be tested by the three years of data already collected by the IceCube-DeepCore. We show that indirect detection through neutrinos can compete with the strong existing limits from direct detection experiments, specially in the case of isospin violation.

Super-Kamiokande Solar Neutrino Results and NSI Analysis

NASA Astrophysics Data System (ADS)

Weatherly, Pierce; Super-Kamiokande Collaboration

2017-09-01

Super-Kamiokande (SK) detects the Cerenkov light from elastic scattering of solar 8B neutrinos with electrons in its ultra-pure water. The directionality, energy, and timing of the recoil electrons determines the interaction rate, the flight path, as well as the energy dependence of the 8B neutrinos’ electron-flavor survival probability P ee . While the P ee below 1 MeV is equivalent to averaged vacuum neutrino flavor oscillations, the P ee above 7 MeV is suppressed by the Mikheyev-Smirnov-Wolfenstein (MSW) resonance resulting from the interaction of the solar neutrinos with solar matter. In the same way, Earth matter effects influence Pee, leading to an apparent Day/Night effect. Non-standard interactions (NSI) extend the MSW model to include interactions between the quarks in matter and neutrinos, thereby modifying P ee . We present the signatures of matter effects on solar neutrinos in Super-Kamiokande and present limits on NSI parameters, in particular couplings to the down quark.

In Situ Generation of Plasmonic Nanoparticles for Manipulating Photon-Plasmon Coupling in Microtube Cavities.

PubMed

Yin, Yin; Wang, Jiawei; Lu, Xueyi; Hao, Qi; Saei Ghareh Naz, Ehsan; Cheng, Chuanfu; Ma, Libo; Schmidt, Oliver G

2018-04-24

In situ generation of silver nanoparticles for selective coupling between localized plasmonic resonances and whispering-gallery modes (WGMs) is investigated by spatially resolved laser dewetting on microtube cavities. The size and morphology of the silver nanoparticles are changed by adjusting the laser power and irradiation time, which in turn effectively tune the photon-plasmon coupling strength. Depending on the relative position of the plasmonic nanoparticles spot and resonant field distribution of WGMs, selective coupling between the localized surface plasmon resonances (LSPRs) and WGMs is experimentally demonstrated. Moreover, by creating multiple plasmonic-nanoparticle spots on the microtube cavity, the field distribution of optical axial modes is freely tuned due to multicoupling between LSPRs and WGMs. The multicoupling mechanism is theoretically investigated by a modified quasipotential model based on perturbation theory. This work provides an in situ fabrication of plasmonic nanoparticles on three-dimensional microtube cavities for manipulating photon-plasmon coupling which is of interest for optical tuning abilities and enhanced light-matter interactions.

Study of the in-medium nucleon electromagnetic form factors using a light-front nucleon wave function combined with the quark-meson coupling model

NASA Astrophysics Data System (ADS)

de Araújo, W. R. B.; de Melo, J. P. B. C.; Tsushima, K.

2018-02-01

We study the nucleon electromagnetic (EM) form factors in symmetric nuclear matter as well as in vacuum within a light-front approach using the in-medium inputs calculated by the quark-meson coupling model. The same in-medium quark properties are used as those used for the study of in-medium pion properties. The zero of the proton EM form factor ratio in vacuum, the electric to magnetic form factor ratio μpGEp (Q2) /GMp (Q2) (Q2 = -q2 > 0 with q being the four-momentum transfer), is determined including the latest experimental data by implementing a hard constituent quark component in the nucleon wave function. A reasonable fit is achieved for the ratio μpGEp (Q2) /GMp (Q2) in vacuum, and we predict that the Q02 value to cross the zero of the ratio to be about 15 GeV2. In addition the double ratio data of the proton EM form factors in 4He and H nuclei, [GEp4He (Q2) /G4HeMp (Q2) ] / [GEp1H (Q2) /GMp1H (Q2) ], extracted by the polarized (e → ,e‧ p →) scattering experiment on 4He at JLab, are well described. We also predict that the Q02 value satisfying μpGEp (Q02) /GMp (Q0 2) = 0 in symmetric nuclear matter, shifts to a smaller value as increasing nuclear matter density, which reflects the facts that the faster falloff of GEp (Q2) as increasing Q2 and the increase of the proton mean-square charge radius. Furthermore, we calculate the neutron EM form factor double ratio in symmetric nuclear matter for 0.1

Ultrastrong Polyoxyzole Nanofiber Membranes for Dendrite-Proof and Heat-Resistant Battery Separators.

PubMed

Hao, Xiaoming; Zhu, Jian; Jiang, Xiong; Wu, Haitao; Qiao, Jinshuo; Sun, Wang; Wang, Zhenhua; Sun, Kening

2016-05-11

Polymeric nanomaterials emerge as key building blocks for engineering materials in a variety of applications. In particular, the high modulus polymeric nanofibers are suitable to prepare flexible yet strong membrane separators to prevent the growth and penetration of lithium dendrites for safe and reliable high energy lithium metal-based batteries. High ionic conductance, scalability, and low cost are other required attributes of the separator important for practical implementations. Available materials so far are difficult to comply with such stringent criteria. Here, we demonstrate a high-yield exfoliation of ultrastrong poly(p-phenylene benzobisoxazole) nanofibers from the Zylon microfibers. A highly scalable blade casting process is used to assemble these nanofibers into nanoporous membranes. These membranes possess ultimate strengths of 525 MPa, Young's moduli of 20 GPa, thermal stability up to 600 °C, and impressively low ionic resistance, enabling their use as dendrite-suppressing membrane separators in electrochemical cells. With such high-performance separators, reliable lithium-metal based batteries operated at 150 °C are also demonstrated. Those polyoxyzole nanofibers would enrich the existing library of strong nanomaterials and serve as a promising material for large-scale and cost-effective safe energy storage.

Adding Spice to Vanilla LCDM simulations: From Alternative Cosmologies to Lighting up Galaxies

NASA Astrophysics Data System (ADS)

Jahan Elahi, Pascal

2015-08-01

Cold Dark Matter simulations have formed the backbone of our theoretical understanding of cosmological structure formation. Predictions from the Lambda Cold Dark Matter (LCDM) cosmology, in which the Universe contains two major dark components, namely Dark Matter and Dark Energy, are in excellent agreement with the Large-Scale Structures observed, i.e., the distribution of galaxies across cosmic time. However, this paradigm is in tension with observations at small-scales, from the number and properties of satellite galaxies around galaxies such as the Milky Way and Andromeda, to the lensing statistics of massive galaxy clusters. I will present several alternative models of cosmology (from Warm Dark Matter to coupled Dark Matter-Dark Energy models) and how they compare to vanilla LCDM by studying formation of groups and clusters dark matter only and adiabatic hydrodynamical zoom simulations. I will show how modifications to the dark sector can lead to some surprising results. For example, Warm Dark Matter, so often examined on small satellite galaxies scales, can be probed observationally using weak lensing at cluster scales. Coupled dark sectors, where dark matter decays into dark energy and experiences an effective gravitational potential that differs from that experienced by normal matter, is effectively hidden away from direct observations of galaxies. Studies like these are vital if we are to pinpoint observations which can look for unique signatures of the physics that governs the hidden Universe. Of course, all of these predictions are unfortunately affected by uncertain galaxy formation physics. I will end by presenting results from a comparison study of numerous hydrodynamical codes, the nIFTY cluster comparison project, and how even how purely adiabatic simulations run with different codes give in quite different galaxy populations. The galaxies that form in these simulations, which all attempt to reproduce the observed galaxy population via not unreasonable subgrid physics, can and do vary in stellar mass, morphology and gas fraction.

First-principles study of the binding energy between nanostructures and its scaling with system size

NASA Astrophysics Data System (ADS)

Tao, Jianmin; Jiao, Yang; Mo, Yuxiang; Yang, Zeng-Hui; Zhu, Jian-Xin; Hyldgaard, Per; Perdew, John P.

2018-04-01

The equilibrium van der Waals binding energy is an important factor in the design of materials and devices. However, it presents great computational challenges for materials built up from nanostructures. Here we investigate the binding-energy scaling behavior from first-principles calculations. We show that the equilibrium binding energy per atom between identical nanostructures can scale up or down with nanostructure size, but can be parametrized for large N with an analytical formula (in meV/atom), Eb/N =a +b /N +c /N2+d /N3 , where N is the number of atoms in a nanostructure and a , b , c , and d are fitting parameters, depending on the properties of a nanostructure. The formula is consistent with a finite large-size limit of binding energy per atom. We find that there are two competing factors in the determination of the binding energy: Nonadditivities of van der Waals coefficients and center-to-center distance between nanostructures. To decode the detail, the nonadditivity of the static multipole polarizability is investigated from an accurate spherical-shell model. We find that the higher-order multipole polarizability displays ultrastrong intrinsic nonadditivity, no matter if the dipole polarizability is additive or not.

Terahertz Nanofocusing with Cantilevered Terahertz-Resonant Antenna Tips.

PubMed

Mastel, Stefan; Lundeberg, Mark B; Alonso-González, Pablo; Gao, Yuanda; Watanabe, Kenji; Taniguchi, Takashi; Hone, James; Koppens, Frank H L; Nikitin, Alexey Y; Hillenbrand, Rainer

2017-11-08

We developed THz-resonant scanning probe tips, yielding strongly enhanced and nanoscale confined THz near fields at their tip apex. The tips with length in the order of the THz wavelength (λ = 96.5 μm) were fabricated by focused ion beam (FIB) machining and attached to standard atomic force microscopy (AFM) cantilevers. Measurements of the near-field intensity at the very tip apex (25 nm radius) as a function of tip length, via graphene-based (thermoelectric) near-field detection, indicate their first and second order geometrical antenna resonances for tip length of 33 and 78 μm, respectively. On resonance, we find that the near-field intensity is enhanced by one order of magnitude compared to tips of 17 μm length (standard AFM tip length), which is corroborated by numerical simulations that further predict remarkable intensity enhancements of about 10 7 relative to the incident field. Because of the strong field enhancement and standard AFM operation of our tips, we envision manifold and straightforward future application in scattering-type THz near-field nanoscopy and THz photocurrent nanoimaging, nanoscale nonlinear THz imaging, or nanoscale control and manipulation of matter employing ultrastrong and ultrashort THz pulses.

Complete Coherent Control of a Quantum Dot Strongly Coupled to a Nanocavity.

PubMed

Dory, Constantin; Fischer, Kevin A; Müller, Kai; Lagoudakis, Konstantinos G; Sarmiento, Tomas; Rundquist, Armand; Zhang, Jingyuan L; Kelaita, Yousif; Vučković, Jelena

2016-04-26

Strongly coupled quantum dot-cavity systems provide a non-linear configuration of hybridized light-matter states with promising quantum-optical applications. Here, we investigate the coherent interaction between strong laser pulses and quantum dot-cavity polaritons. Resonant excitation of polaritonic states and their interaction with phonons allow us to observe coherent Rabi oscillations and Ramsey fringes. Furthermore, we demonstrate complete coherent control of a quantum dot-photonic crystal cavity based quantum-bit. By controlling the excitation power and phase in a two-pulse excitation scheme we achieve access to the full Bloch sphere. Quantum-optical simulations are in good agreement with our experiments and provide insight into the decoherence mechanisms.

Complete Coherent Control of a Quantum Dot Strongly Coupled to a Nanocavity

NASA Astrophysics Data System (ADS)

Dory, Constantin; Fischer, Kevin A.; Müller, Kai; Lagoudakis, Konstantinos G.; Sarmiento, Tomas; Rundquist, Armand; Zhang, Jingyuan L.; Kelaita, Yousif; Vučković, Jelena

2016-04-01

Strongly coupled quantum dot-cavity systems provide a non-linear configuration of hybridized light-matter states with promising quantum-optical applications. Here, we investigate the coherent interaction between strong laser pulses and quantum dot-cavity polaritons. Resonant excitation of polaritonic states and their interaction with phonons allow us to observe coherent Rabi oscillations and Ramsey fringes. Furthermore, we demonstrate complete coherent control of a quantum dot-photonic crystal cavity based quantum-bit. By controlling the excitation power and phase in a two-pulse excitation scheme we achieve access to the full Bloch sphere. Quantum-optical simulations are in good agreement with our experiments and provide insight into the decoherence mechanisms.

Improved Limits on Spin-Mass Interactions

NASA Astrophysics Data System (ADS)

Lee, Junyi; Almasi, Attaallah; Romalis, Michael

2018-04-01

Very light particles with C P -violating couplings to ordinary matter, such as axions or axionlike particles, can mediate long-range forces between polarized and unpolarized fermions. We describe a new experimental search for such forces between unpolarized nucleons in two 250 kg Pb weights and polarized neutrons and electrons in a 3He -K comagnetometer located about 15 cm away. We place improved constraints on the products of scalar and pseudoscalar coupling constants, gpngsN<4.2 ×10-30 and gpegsN<1.7 ×10-30 (95% C.L.) for axionlike particle masses less than 10-6 eV , which represents an order of magnitude improvement over the best previous neutron laboratory limit.

Inverse Stellation of CuAu-ZnO Multimetallic-Semiconductor Nanostartube for Plasmon-Enhanced Photocatalysis.

PubMed

Tan, Chuan Fu; Su Su Zin, Aung Kyi; Chen, Zhihui; Liow, Chi Hao; Phan, Huy Thong; Tan, Hui Ru; Xu, Qing-Hua; Ho, Ghim Wei

2018-05-22

One-dimensional (1D) metallic nanocrystals constitute an important class of plasmonic materials for localization of light into subwavelength dimensions. Coupled with their intrinsic conductive properties and extended optical paths for light absorption, metallic nanowires are prevalent in light-harnessing applications. However, the transverse surface plasmon resonance (SPR) mode of traditional multiply twinned nanowires often suffers from weaker electric field enhancement due to its low degree of morphological curvature in comparison to other complex anisotropic nanocrystals. Herein, simultaneous anisotropic stellation and excavation of multiply twinned nanowires are demonstrated through a site-selective galvanic reaction for a pronounced manipulation of light-matter interaction. The introduction of longitudinal extrusions and cavitation along the nanowires leads to a significant enhancement in plasmon field with reduced quenching of localized surface plasmon resonance (LSPR). The as-synthesized multimetallic nanostartubes serve as a panchromatic plasmonic framework for incorporation of photocatalytic materials for plasmon-assisted solar fuel production.

In-Medium K^+ Electromagnetic Form Factor with a Symmetric Vertex in a Light Front Approach

NASA Astrophysics Data System (ADS)

Yabusaki, George H. S.; de Melo, J. P. B. C.; de Paula, Wayne; Tsushima, K.; Frederico, T.

2018-05-01

Using the light-front K^ +-Meson wave function based on a Bethe-Salpeter amplitude model for the Quark-Antiquark bound state, we study the Electromagnetic Form Factor (EMFF) of the K^ +-Meson in nuclear medium within the framework of light-front field theory. The K^ +-Meson model we adopt is well constrained by previous and recent studies to explain its properties in vacuum. The in-medium K^ +-Meson EMFF is evaluated for the plus-component of the electromagnetic current, J^+, in the Breit frame. In order to consistently incorporate the constituent up and antistrange Quarks of the K^ +-Meson immersed in symmetric nuclear matter, we use the Quark-Meson coupling model, which has been widely applied to various hadronic and nuclear phenomena in a nuclear medium with success. We predict the in-medium modification of the K^ +-Meson EMFF in symmetric nuclear matter. It is found that, after a fine tuning of the regulator mass, i.e. m_R = 0.600 GeV, the model is suitable to fit the available experimental data in vacuum within the theoretical uncertainties, and based on this we predict the in-medium modification of the K^ +-Meson EMFF.

COSMOLOGY OF CHAMELEONS WITH POWER-LAW COUPLINGS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mota, David F.; Winther, Hans A.

2011-05-20

In chameleon field theories, a scalar field can couple to matter with gravitational strength and still evade local gravity constraints due to a combination of self-interactions and the couplings to matter. Originally, these theories were proposed with a constant coupling to matter; however, the chameleon mechanism also extends to the case where the coupling becomes field dependent. We study the cosmology of chameleon models with power-law couplings and power-law potentials. It is found that these generalized chameleons, when viable, have a background expansion very close to {Lambda}CDM, but can in some special cases enhance the growth of the linear perturbationsmore » at low redshifts. For the models we consider, it is found that this region of the parameter space is ruled out by local gravity constraints. Imposing a coupling to dark matter only, the local constraints are avoided, and it is possible to have observable signatures on the linear matter perturbations.« less

Engineering electric and magnetic dipole coupling in arrays of dielectric nanoparticles

NASA Astrophysics Data System (ADS)

Li, Jiaqi; Verellen, Niels; Van Dorpe, Pol

2018-02-01

Dielectric nanoparticles with both strong electric and magnetic dipole (ED and MD) resonances offer unique opportunities for efficient manipulation of light-matter interactions. Here, based on numerical simulations, we show far-field diffractive coupling of the ED and MD modes in a periodic rectangular array. By using unequal periodicities in the orthogonal directions, each dipole mode is separately coupled and strongly tuned. With this method, the electric and magnetic response of the dielectric nanoparticles can be deliberately engineered to accomplish various optical functionalities. Remarkably, an ultra-sharp MD resonance with sub-10 nm linewidth is achieved with a large enhancement factor for the magnetic field intensity on the order of ˜103. Our results will find useful applications for the detection of chemical and biological molecules as well as the design of novel photonic metadevices.

Light dark matter, naturalness, and the radiative origin of the electroweak scale

DOE PAGES

Altmannshofer, Wolfgang; Bardeen, William A.; Bauer, Martin; ...

2015-01-09

We study classically scale invariant models in which the Standard Model Higgs mass term is replaced in the Lagrangian by a Higgs portal coupling to a complex scalar field of a dark sector. We focus on models that are weakly coupled with the quartic scalar couplings nearly vanishing at the Planck scale. The dark sector contains fermions and scalars charged under dark SU(2) × U(1) gauge interactions. Radiative breaking of the dark gauge group triggers electroweak symmetry breaking through the Higgs portal coupling. Requiring both a Higgs boson mass of 125.5 GeV and stability of the Higgs potential up tomore » the Planck scale implies that the radiative breaking of the dark gauge group occurs at the TeV scale. We present a particular model which features a long-range abelian dark force. The dominant dark matter component is neutral dark fermions, with the correct thermal relic abundance, and in reach of future direct detection experiments. The model also has lighter stable dark fermions charged under the dark force, with observable effects on galactic-scale structure. Collider signatures include a dark sector scalar boson with mass ≲ 250 GeV that decays through mixing with the Higgs boson, and can be detected at the LHC. As a result, the Higgs boson, as well as the new scalar, may have significant invisible decays into dark sector particles.« less

Laser optomechanics

NASA Astrophysics Data System (ADS)

Yang, Weijian; Adair Gerke, Stephen; Wei Ng, Kar; Rao, Yi; Chase, Christopher; Chang-Hasnain, Connie J.

2015-09-01

Cavity optomechanics explores the interaction between optical field and mechanical motion. So far, this interaction has relied on the detuning between a passive optical resonator and an external pump laser. Here, we report a new scheme with mutual coupling between a mechanical oscillator supporting the mirror of a laser and the optical field generated by the laser itself. The optically active cavity greatly enhances the light-matter energy transfer. In this work, we use an electrically-pumped vertical-cavity surface-emitting laser (VCSEL) with an ultra-light-weight (130 pg) high-contrast-grating (HCG) mirror, whose reflectivity spectrum is designed to facilitate strong optomechanical coupling, to demonstrate optomechanically-induced regenerative oscillation of the laser optomechanical cavity. We observe >550 nm self-oscillation amplitude of the micromechanical oscillator, two to three orders of magnitude larger than typical, and correspondingly a 23 nm laser wavelength sweep. In addition to its immediate applications as a high-speed wavelength-swept source, this scheme also offers a new approach for integrated on-chip sensors.

Tailoring the Spectroscopic Properties of Semiconductor Nanowires via Surface-Plasmon-Based Optical Engineering

PubMed Central

2014-01-01

Semiconductor nanowires, due to their unique electronic, optical, and chemical properties, are firmly placed at the forefront of nanotechnology research. The rich physics of semiconductor nanowire optics arises due to the enhanced light–matter interactions at the nanoscale and coupling of optical modes to electronic resonances. Furthermore, confinement of light can be taken to new extremes via coupling to the surface plasmon modes of metal nanostructures integrated with nanowires, leading to interesting physical phenomena. This Perspective will examine how the optical properties of semiconductor nanowires can be altered via their integration with highly confined plasmonic nanocavities that have resulted in properties such as orders of magnitude faster and more efficient light emission and lasing. The use of plasmonic nanocavities for tailored optical absorption will also be discussed in order to understand and engineer fundamental optical properties of these hybrid systems along with their potential for novel applications, which may not be possible with purely dielectric cavities. PMID:25396030

Probing the Wave Nature of Light-Matter Interaction

DOE PAGES

Boone, D. E.; Jackson, C. H.; Swecker, A. T.; ...

2018-05-30

Here, the wave-particle duality of light is a controversial topic in modern physics. In this context, this work highlights the ability of the wave-nature of light on its own to account for the conservation of energy in light-matter interaction. Two simple fundamental properties of light as wave are involved: its period and its power P. The power P depends only on the amplitude of the wave’s electric and magnetic fields (Poynting’s vector), and can easily be measured with a power sensor for visible and infrared lasers. The advantage of such a wave-based approach is that it unveils unexpected effects ofmore » light’s power P capable of explaining numerous results published in current scientific literature, of correlating phenomena otherwise considered as disjointed, and of making predictions on ways to employ the electromagnetic (EM) waves which so far are unexplored. In this framework, this work focuses on determining the magnitude of the time interval that, coupled with light’s power P, establishes the energy conserved in the exchange of energy between light and matter. To reach this goal, capacitors were excited with visible and IR lasers at variable average power P. As the result of combining experimental measurements and simulations based on the law of conservation of energy, it was found that the product of the period of the light by its power P fixes the magnitude of the energy conserved in light’s interaction with the capacitors. This finding highlights that the energy exchanged is defined in the time interval equal to the period of the light’s wave. The validity of the finding is shown to hold in light’s interaction with matter in general, e.g. in the photoelectric effect with x-rays, in the transfer of electrons between energy levels in semiconductingfield effect transistors, in the activation of photosynthetic reactions, and in the generation of action potentials in retinal ganglion cells to enable vision in vertebrates. Finally, the validity of the finding is investigated in the low frequency spectrum of the EM waves by exploring possible consequences in microwave technology, and in harvesting through capacitors the radio waves dispersed in the environment after being used in telecommunications as a source of usable electricity.« less

Probing the Wave Nature of Light-Matter Interaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boone, D. E.; Jackson, C. H.; Swecker, A. T.

Here, the wave-particle duality of light is a controversial topic in modern physics. In this context, this work highlights the ability of the wave-nature of light on its own to account for the conservation of energy in light-matter interaction. Two simple fundamental properties of light as wave are involved: its period and its power P. The power P depends only on the amplitude of the wave’s electric and magnetic fields (Poynting’s vector), and can easily be measured with a power sensor for visible and infrared lasers. The advantage of such a wave-based approach is that it unveils unexpected effects ofmore » light’s power P capable of explaining numerous results published in current scientific literature, of correlating phenomena otherwise considered as disjointed, and of making predictions on ways to employ the electromagnetic (EM) waves which so far are unexplored. In this framework, this work focuses on determining the magnitude of the time interval that, coupled with light’s power P, establishes the energy conserved in the exchange of energy between light and matter. To reach this goal, capacitors were excited with visible and IR lasers at variable average power P. As the result of combining experimental measurements and simulations based on the law of conservation of energy, it was found that the product of the period of the light by its power P fixes the magnitude of the energy conserved in light’s interaction with the capacitors. This finding highlights that the energy exchanged is defined in the time interval equal to the period of the light’s wave. The validity of the finding is shown to hold in light’s interaction with matter in general, e.g. in the photoelectric effect with x-rays, in the transfer of electrons between energy levels in semiconductingfield effect transistors, in the activation of photosynthetic reactions, and in the generation of action potentials in retinal ganglion cells to enable vision in vertebrates. Finally, the validity of the finding is investigated in the low frequency spectrum of the EM waves by exploring possible consequences in microwave technology, and in harvesting through capacitors the radio waves dispersed in the environment after being used in telecommunications as a source of usable electricity.« less

Search for associated production of dark matter with a Higgs boson decaying to b\\overline{b} or γγ at √{s}=13 TeV

NASA Astrophysics Data System (ADS)

Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.; Dragicevic, M.; Erö, J.; Flechl, M.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hartl, C.; Hörmann, N.; Hrubec, J.; Jeitler, M.; König, A.; Krätschmer, I.; Liko, D.; Matsushita, T.; Mikulec, I.; Rabady, D.; Rad, N.; Rahbaran, B.; Rohringer, H.; Schieck, J.; Strauss, J.; Waltenberger, W.; Wulz, C.-E.; Dvornikov, O.; Makarenko, V.; Mossolov, V.; Gonzalez, J. Suarez; Zykunov, V.; Shumeiko, N.; Alderweireldt, S.; De Wolf, E. A.; Janssen, X.; Lauwers, J.; Van De Klundert, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Zeid, S. Abu; Blekman, F.; D'Hondt, J.; Daci, N.; De Bruyn, I.; Deroover, K.; Lowette, S.; Moortgat, S.; Moreels, L.; Olbrechts, A.; Python, Q.; Skovpen, K.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Parijs, I.; Brun, H.; Clerbaux, B.; De Lentdecker, G.; Delannoy, H.; Fasanella, G.; Favart, L.; Goldouzian, R.; Grebenyuk, A.; Karapostoli, G.; Lenzi, T.; Léonard, A.; Luetic, J.; Maerschalk, T.; Marinov, A.; Randle-conde, A.; Seva, T.; Velde, C. Vander; Vanlaer, P.; Vannerom, D.; Yonamine, R.; Zenoni, F.; Zhang, F.; Cornelis, T.; Dobur, D.; Fagot, A.; Gul, M.; Khvastunov, I.; Poyraz, D.; Salva, S.; Schöfbeck, R.; Tytgat, M.; Van Driessche, W.; Yazgan, E.; Zaganidis, N.; Bakhshiansohi, H.; Bondu, O.; Brochet, S.; Bruno, G.; Caudron, A.; De Visscher, S.; Delaere, C.; Delcourt, M.; Francois, B.; Giammanco, A.; Jafari, A.; Komm, M.; Krintiras, G.; Lemaitre, V.; Magitteri, A.; Mertens, A.; Musich, M.; Piotrzkowski, K.; Quertenmont, L.; Selvaggi, M.; Marono, M. Vidal; Wertz, S.; Beliy, N.; Júnior, W. L. Aldá; Alves, F. L.; Alves, G. A.; Brito, L.; Hensel, C.; Moraes, A.; Pol, M. E.; Teles, P. Rebello; Belchior Batista Das Chagas, E.; Carvalho, W.; Chinellato, J.; Custódio, A.; Da Costa, E. M.; Da Silveira, G. G.; De Jesus Damiao, D.; De Oliveira Martins, C.; De Souza, S. Fonseca; Guativa, L. M. Huertas; Malbouisson, H.; Figueiredo, D. Matos; Herrera, C. Mora; Mundim, L.; Nogima, H.; Prado Da Silva, W. L.; Santoro, A.; Sznajder, A.; Manganote, E. J. Tonelli; Da Silva De Araujo, F. Torres; Pereira, A. Vilela; Ahuja, S.; Bernardes, C. A.; Dogra, S.; Tomei, T. R. Fernandez Perez; Gregores, E. M.; Mercadante, P. G.; Moon, C. S.; Novaes, S. F.; Padula, Sandra S.; Abad, D. Romero; Vargas, J. C. Ruiz; Aleksandrov, A.; Hadjiiska, R.; Iaydjiev, P.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Glushkov, I.; Litov, L.; Pavlov, B.; Petkov, P.; Fang, W.; Ahmad, M.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Chen, M.; Chen, Y.; Cheng, T.; Jiang, C. H.; Leggat, D.; Liu, Z.; Romeo, F.; Ruan, M.; Shaheen, S. M.; Spiezia, A.; Tao, J.; Wang, C.; Wang, Z.; Zhang, H.; Zhao, J.; Ban, Y.; Chen, G.; Li, Q.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Xu, Z.; Avila, C.; Cabrera, A.; Sierra, L. F. Chaparro; Florez, C.; Gomez, J. P.; Hernández, C. F. González; Alvarez, J. D. Ruiz; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Puljak, I.; Cipriano, P. M. Ribeiro; Sculac, T.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Ferencek, D.; Kadija, K.; Mesic, B.; Susa, T.; Ather, M. W.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Rykaczewski, H.; Finger, M.; Finger, M.; Jarrin, E. Carrera; Abdelalim, A. A.; Mohammed, Y.; Salama, E.; Kadastik, M.; Perrini, L.; Raidal, M.; Tiko, A.; Veelken, C.; Eerola, P.; Pekkanen, J.; Voutilainen, M.; Härkönen, J.; Järvinen, T.; Karimäki, V.; Kinnunen, R.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Tuominiemi, J.; Tuovinen, E.; Wendland, L.; Talvitie, J.; Tuuva, T.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Favaro, C.; Ferri, F.; Ganjour, S.; Ghosh, S.; Givernaud, A.; Gras, P.; de Monchenault, G. Hamel; Jarry, P.; Kucher, I.; Locci, E.; Machet, M.; Malcles, J.; Rander, J.; Rosowsky, A.; Titov, M.; Abdulsalam, A.; Amendola, C.; Antropov, I.; Baffioni, S.; Beaudette, F.; Busson, P.; Cadamuro, L.; Chapon, E.; Charlot, C.; Davignon, O.; de Cassagnac, R. Granier; Jo, M.; Lisniak, S.; Miné, P.; Nguyen, M.; Ochando, C.; Ortona, G.; Paganini, P.; Pigard, P.; Regnard, S.; Salerno, R.; Sirois, Y.; Leiton, A. G. Stahl; Strebler, T.; Yilmaz, Y.; Zabi, A.; Zghiche, A.; Agram, J.-L.; Andrea, J.; Bloch, D.; Brom, J.-M.; Buttignol, M.; Chabert, E. C.; Chanon, N.; Collard, C.; Conte, E.; Coubez, X.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Le Bihan, A.-C.; Van Hove, P.; Gadrat, S.; Beauceron, S.; Bernet, C.; Boudoul, G.; Montoya, C. A. Carrillo; Chierici, R.; Contardo, D.; Courbon, B.; Depasse, P.; El Mamouni, H.; Fay, J.; Gascon, S.; Gouzevitch, M.; Grenier, G.; Ille, B.; Lagarde, F.; Laktineh, I. B.; Lethuillier, M.; Mirabito, L.; Pequegnot, A. L.; Perries, S.; Popov, A.; Sordini, V.; Donckt, M. Vander; Verdier, P.; Viret, S.; Toriashvili, T.; Tsamalaidze, Z.; Autermann, C.; Beranek, S.; Feld, L.; Kiesel, M. K.; Klein, K.; Lipinski, M.; Preuten, M.; Schomakers, C.; Schulz, J.; Verlage, T.; Albert, A.; Brodski, M.; Dietz-Laursonn, E.; Duchardt, D.; Endres, M.; Erdmann, M.; Erdweg, S.; Esch, T.; Fischer, R.; Güth, A.; Hamer, M.; Hebbeker, T.; Heidemann, C.; Hoepfner, K.; Knutzen, S.; Merschmeyer, M.; Meyer, A.; Millet, P.; Mukherjee, S.; Olschewski, M.; Padeken, K.; Pook, T.; Radziej, M.; Reithler, H.; Rieger, M.; Scheuch, F.; Sonnenschein, L.; Teyssier, D.; Thüer, S.; Cherepanov, V.; Flügge, G.; Kargoll, B.; Kress, T.; Künsken, A.; Lingemann, J.; Müller, T.; Nehrkorn, A.; Nowack, A.; Pistone, C.; Pooth, O.; Stahl, A.; Martin, M. Aldaya; Arndt, T.; Asawatangtrakuldee, C.; Beernaert, K.; Behnke, O.; Behrens, U.; Anuar, A. A. Bin; Borras, K.; Campbell, A.; Connor, P.; Contreras-Campana, C.; Costanza, F.; Pardos, C. Diez; Dolinska, G.; Eckerlin, G.; Eckstein, D.; Eichhorn, T.; Eren, E.; Gallo, E.; Garcia, J. Garay; Geiser, A.; Gizhko, A.; Luyando, J. M. Grados; Grohsjean, A.; Gunnellini, P.; Harb, A.; Hauk, J.; Hempel, M.; Jung, H.; Kalogeropoulos, A.; Karacheban, O.; Kasemann, M.; Keaveney, J.; Kleinwort, C.; Korol, I.; Krücker, D.; Lange, W.; Lelek, A.; Lenz, T.; Leonard, J.; Lipka, K.; Lobanov, A.; Lohmann, W.; Mankel, R.; Melzer-Pellmann, I.-A.; Meyer, A. B.; Mittag, G.; Mnich, J.; Mussgiller, A.; Pitzl, D.; Placakyte, R.; Raspereza, A.; Roland, B.; Sahin, M. Ö.; Saxena, P.; SchoernerSadenius, T.; Spannagel, S.; Stefaniuk, N.; Van Onsem, G. P.; Walsh, R.; Wissing, C.; Blobel, V.; Vignali, M. Centis; Draeger, A. R.; Dreyer, T.; Garutti, E.; Gonzalez, D.; Haller, J.; Hoffmann, M.; Junkes, A.; Klanner, R.; Kogler, R.; Kovalchuk, N.; Kurz, S.; Lapsien, T.; Marchesini, I.; Marconi, D.; Meyer, M.; Niedziela, M.; Nowatschin, D.; Pantaleo, F.; Peiffer, T.; Perieanu, A.; Scharf, C.; Schleper, P.; Schmidt, A.; Schumann, S.; Schwandt, J.; Sonneveld, J.; Stadie, H.; Steinbrück, G.; Stober, F. M.; Stöver, M.; Tholen, H.; Troendle, D.; Usai, E.; Vanelderen, L.; Vanhoefer, A.; Vormwald, B.; Akbiyik, M.; Barth, C.; Baur, S.; Baus, C.; Berger, J.; Butz, E.; Caspart, R.; Chwalek, T.; Colombo, F.; De Boer, W.; Dierlamm, A.; Fink, S.; Freund, B.; Friese, R.; Giffels, M.; Gilbert, A.; Goldenzweig, P.; Haitz, D.; Hartmann, F.; Heindl, S. M.; Husemann, U.; Kassel, F.; Katkov, I.; Kudella, S.; Mildner, H.; Mozer, M. U.; Müller, Th.; Plagge, M.; Quast, G.; Rabbertz, K.; Röcker, S.; Roscher, F.; Schröder, M.; Shvetsov, I.; Sieber, G.; Simonis, H. J.; Ulrich, R.; Wayand, S.; Weber, M.; Weiler, T.; Williamson, S.; Wöhrmann, C.; Wolf, R.; Anagnostou, G.; Daskalakis, G.; Geralis, T.; Giakoumopoulou, V. A.; Kyriakis, A.; Loukas, D.; Topsis-Giotis, I.; Kesisoglou, S.; Panagiotou, A.; Saoulidou, N.; Tziaferi, E.; Evangelou, I.; Flouris, G.; Foudas, C.; Kokkas, P.; Loukas, N.; Manthos, N.; Papadopoulos, I.; Paradas, E.; Filipovic, N.; Pasztor, G.; Bencze, G.; Hajdu, C.; Horvath, D.; Sikler, F.; Veszpremi, V.; Vesztergombi, G.; Zsigmond, A. J.; Beni, N.; Czellar, S.; Karancsi, J.; Makovec, A.; Molnar, J.; Szillasi, Z.; Bartók, M.; Raics, P.; Trocsanyi, Z. L.; Ujvari, B.; Choudhury, S.; Komaragiri, J. R.; Bahinipati, S.; Bhowmik, S.; Mal, P.; Mandal, K.; Nayak, A.; Sahoo, D. K.; Sahoo, N.; Swain, S. K.; Bansal, S.; Beri, S. B.; Bhatnagar, V.; Chawla, R.; Bhawandeep, U.; Kalsi, A. K.; Kaur, A.; Kaur, M.; Kumar, R.; Kumari, P.; Mehta, A.; Mittal, M.; Singh, J. B.; Walia, G.; Kumar, Ashok; Bhardwaj, A.; Choudhary, B. C.; Garg, R. B.; Keshri, S.; Kumar, A.; Malhotra, S.; Naimuddin, M.; Ranjan, K.; Sharma, R.; Sharma, V.; Bhattacharya, R.; Bhattacharya, S.; Chatterjee, K.; Dey, S.; Dutt, S.; Dutta, S.; Ghosh, S.; Majumdar, N.; Modak, A.; Mondal, K.; Mukhopadhyay, S.; Nandan, S.; Purohit, A.; Roy, A.; Roy, D.; Chowdhury, S. Roy; Sarkar, S.; Sharan, M.; Thakur, S.; Behera, P. K.; Chudasama, R.; Dutta, D.; Jha, V.; Kumar, V.; Mohanty, A. K.; Netrakanti, P. K.; Pant, L. M.; Shukla, P.; Topkar, A.; Aziz, T.; Dugad, S.; Kole, G.; Mahakud, B.; Mitra, S.; Mohanty, G. B.; Parida, B.; Sur, N.; Sutar, B.; Banerjee, S.; Dewanjee, R. K.; Ganguly, S.; Guchait, M.; Jain, Sa.; Kumar, S.; Maity, M.; Majumder, G.; Mazumdar, K.; Sarkar, T.; Wickramage, N.; Chauhan, S.; Dube, S.; Hegde, V.; Kapoor, A.; Kothekar, K.; Pandey, S.; Rane, A.; Sharma, S.; Chenarani, S.; Tadavani, E. Eskandari; Etesami, S. M.; Khakzad, M.; Najafabadi, M. Mohammadi; Naseri, M.; Mehdiabadi, S. Paktinat; Hosseinabadi, F. Rezaei; Safarzadeh, B.; Zeinali, M.; Felcini, M.; Grunewald, M.; Abbrescia, M.; Calabria, C.; Caputo, C.; Colaleo, A.; Creanza, D.; Cristella, L.; De Filippis, N.; De Palma, M.; Fiore, L.; Iaselli, G.; Maggi, G.; Maggi, M.; Miniello, G.; My, S.; Nuzzo, S.; Pompili, A.; Pugliese, G.; Radogna, R.; Ranieri, A.; Selvaggi, G.; Sharma, A.; Silvestris, L.; Venditti, R.; Verwilligen, P.; Abbiendi, G.; Battilana, C.; Bonacorsi, D.; Braibant-Giacomelli, S.; Brigliadori, L.; Campanini, R.; Capiluppi, P.; Castro, A.; Cavallo, F. R.; Chhibra, S. S.; Codispoti, G.; Cuffiani, M.; Dallavalle, G. M.; Fabbri, F.; Fanfani, A.; Fasanella, D.; Giacomelli, P.; Grandi, C.; Guiducci, L.; Marcellini, S.; Masetti, G.; Montanari, A.; Navarria, F. L.; Perrotta, A.; Rossi, A. M.; Rovelli, T.; Siroli, G. P.; Tosi, N.; Albergo, S.; Costa, S.; Di Mattia, A.; Giordano, F.; Potenza, R.; Tricomi, A.; Tuve, C.; Barbagli, G.; Ciulli, V.; Civinini, C.; D'Alessandro, R.; Focardi, E.; Lenzi, P.; Meschini, M.; Paoletti, S.; Russo, L.; Sguazzoni, G.; Strom, D.; Viliani, L.; Benussi, L.; Bianco, S.; Fabbri, F.; Piccolo, D.; Primavera, F.; Calvelli, V.; Ferro, F.; Monge, M. R.; Robutti, E.; Tosi, S.; Brianza, L.; Brivio, F.; Ciriolo, V.; Dinardo, M. E.; Fiorendi, S.; Gennai, S.; Ghezzi, A.; Govoni, P.; Malberti, M.; Malvezzi, S.; Manzoni, R. A.; Menasce, D.; Moroni, L.; Paganoni, M.; Pedrini, D.; Pigazzini, S.; Ragazzi, S.; de Fatis, T. Tabarelli; Buontempo, S.; Cavallo, N.; De Nardo, G.; Di Guida, S.; Esposito, M.; Fabozzi, F.; Fienga, F.; Iorio, A. O. M.; Lanza, G.; Lista, L.; Meola, S.; Paolucci, P.; Sciacca, C.; Thyssen, F.; Azzi, P.; Bacchetta, N.; Benato, L.; Bisello, D.; Boletti, A.; Carlin, R.; De Oliveira, A. Carvalho Antunes; Checchia, P.; Dall'Osso, M.; De Castro Manzano, P.; Dorigo, T.; Dosselli, U.; Gasparini, F.; Gasparini, U.; Lacaprara, S.; Margoni, M.; Meneguzzo, A. T.; Pazzini, J.; Pozzobon, N.; Ronchese, P.; Rossin, R.; Simonetto, F.; Torassa, E.; Zanetti, M.; Zotto, P.; Zumerle, G.; Braghieri, A.; Fallavollita, F.; Magnani, A.; Montagna, P.; Ratti, S. P.; Re, V.; Ressegotti, M.; Riccardi, C.; Salvini, P.; Vai, I.; Vitulo, P.; Solestizi, L. Alunni; Bilei, G. M.; Ciangottini, D.; Fanò, L.; Lariccia, P.; Leonardi, R.; Mantovani, G.; Mariani, V.; Menichelli, M.; Saha, A.; Santocchia, A.; Androsov, K.; Azzurri, P.; Bagliesi, G.; Bernardini, J.; Boccali, T.; Castaldi, R.; Ciocci, M. A.; Dell'Orso, R.; Fedi, G.; Giassi, A.; Grippo, M. T.; Ligabue, F.; Lomtadze, T.; Martini, L.; Messineo, A.; Palla, F.; Rizzi, A.; Savoy-Navarro, A.; Spagnolo, P.; Tenchini, R.; Tonelli, G.; Venturi, A.; Verdini, P. G.; Barone, L.; Cavallari, F.; Cipriani, M.; Del Re, D.; Diemoz, M.; Gelli, S.; Longo, E.; Margaroli, F.; Marzocchi, B.; Meridiani, P.; Organtini, G.; Paramatti, R.; Preiato, F.; Rahatlou, S.; Rovelli, C.; Santanastasio, F.; Amapane, N.; Arcidiacono, R.; Argiro, S.; Arneodo, M.; Bartosik, N.; Bellan, R.; Biino, C.; Cartiglia, N.; Cenna, F.; Costa, M.; Covarelli, R.; Degano, A.; Demaria, N.; Finco, L.; Kiani, B.; Mariotti, C.; Maselli, S.; Migliore, E.; Monaco, V.; Monteil, E.; Monteno, M.; Obertino, M. M.; Pacher, L.; Pastrone, N.; Pelliccioni, M.; Angioni, G. L. Pinna; Ravera, F.; Romero, A.; Ruspa, M.; Sacchi, R.; Shchelina, K.; Sola, V.; Solano, A.; Staiano, A.; Traczyk, P.; Belforte, S.; Casarsa, M.; Cossutti, F.; Ricca, G. Della; Zanetti, A.; Kim, D. H.; Kim, G. N.; Kim, M. S.; Lee, S.; Lee, S. W.; Oh, Y. D.; Sekmen, S.; Son, D. C.; Yang, Y. C.; Lee, A.; Kim, H.; Cifuentes, J. A. Brochero; Kim, T. J.; Cho, S.; Choi, S.; Go, Y.; Gyun, D.; Ha, S.; Hong, B.; Jo, Y.; Kim, Y.; Lee, K.; Lee, K. S.; Lee, S.; Lim, J.; Park, S. K.; Roh, Y.; Almond, J.; Kim, J.; Lee, H.; Oh, S. B.; Radburn-Smith, B. C.; Seo, S. h.; Yang, U. K.; Yoo, H. D.; Yu, G. B.; Choi, M.; Kim, H.; Kim, J. H.; Lee, J. S. H.; Park, I. C.; Ryu, G.; Ryu, M. S.; Choi, Y.; Goh, J.; Hwang, C.; Lee, J.; Yu, I.; Dudenas, V.; Juodagalvis, A.; Vaitkus, J.; Ahmed, I.; Ibrahim, Z. A.; Ali, M. A. B. Md; Idris, F. Mohamad; Abdullah, W. A. T. Wan; Yusli, M. N.; Zolkapli, Z.; Castilla-Valdez, H.; De La Cruz-Burelo, E.; Heredia-De La Cruz, I.; Hernandez-Almada, A.; Lopez-Fernandez, R.; Villalba, R. Magaña; Guisao, J. Mejia; Sanchez-Hernandez, A.; Moreno, S. Carrillo; Barrera, C. Oropeza; Valencia, F. Vazquez; Carpinteyro, S.; Pedraza, I.; Ibarguen, H. A. Salazar; Estrada, C. Uribe; Pineda, A. Morelos; Krofcheck, D.; Butler, P. H.; Ahmad, A.; Ahmad, M.; Hassan, Q.; Hoorani, H. R.; Khan, W. A.; Saddique, A.; Shah, M. A.; Shoaib, M.; Waqas, M.; Bialkowska, H.; Bluj, M.; Boimska, B.; Frueboes, T.; Górski, M.; Kazana, M.; Nawrocki, K.; Romanowska-Rybinska, K.; Szleper, M.; Zalewski, P.; Bunkowski, K.; Byszuk, A.; Doroba, K.; Kalinowski, A.; Konecki, M.; Krolikowski, J.; Misiura, M.; Olszewski, M.; Walczak, M.; Bargassa, P.; Da Cruz E Silva, C. Beirão; Calpas, B.; Di Francesco, A.; Faccioli, P.; Gallinaro, M.; Hollar, J.; Leonardo, N.; Iglesias, L. Lloret; Nemallapudi, M. V.; Seixas, J.; Toldaiev, O.; Vadruccio, D.; Varela, J.; Afanasiev, S.; Bunin, P.; Gavrilenko, M.; Golutvin, I.; Gorbunov, I.; Kamenev, A.; Karjavin, V.; Lanev, A.; Malakhov, A.; Matveev, V.; Palichik, V.; Perelygin, V.; Shmatov, S.; Shulha, S.; Skatchkov, N.; Smirnov, V.; Voytishin, N.; Zarubin, A.; Chtchipounov, L.; Golovtsov, V.; Ivanov, Y.; Kim, V.; Kuznetsova, E.; Murzin, V.; Oreshkin, V.; Sulimov, V.; Vorobyev, A.; Andreev, Yu.; Dermenev, A.; Gninenko, S.; Golubev, N.; Karneyeu, A.; Kirsanov, M.; Krasnikov, N.; Pashenkov, A.; Tlisov, D.; Toropin, A.; Epshteyn, V.; Gavrilov, V.; Lychkovskaya, N.; Popov, V.; Pozdnyakov, I.; Safronov, G.; Spiridonov, A.; Toms, M.; Vlasov, E.; Zhokin, A.; Aushev, T.; Bylinkin, A.; Danilov, M.; Popova, E.; Rusinov, V.; Andreev, V.; Azarkin, M.; Dremin, I.; Kirakosyan, M.; Leonidov, A.; Terkulov, A.; Baskakov, A.; Belyaev, A.; Boos, E.; Bunichev, V.; Dubinin, M.; Dudko, L.; Ershov, A.; Gribushin, A.; Klyukhin, V.; Kodolova, O.; Lokhtin, I.; Miagkov, I.; Obraztsov, S.; Savrin, V.; Snigirev, A.; Blinov, V.; Skovpen, Y.; Shtol, D.; Azhgirey, I.; Bayshev, I.; Bitioukov, S.; Elumakhov, D.; Kachanov, V.; Kalinin, A.; Konstantinov, D.; Krychkine, V.; Petrov, V.; Ryutin, R.; Sobol, A.; Troshin, S.; Tyurin, N.; Uzunian, A.; Volkov, A.; Adzic, P.; Cirkovic, P.; Devetak, D.; Dordevic, M.; Milosevic, J.; Rekovic, V.; Maestre, J. Alcaraz; Luna, M. Barrio; Calvo, E.; Cerrada, M.; Llatas, M. Chamizo; Colino, N.; De La Cruz, B.; Peris, A. Delgado; Del Valle, A. Escalante; Bedoya, C. Fernandez; Ramos, J. P. Fernández; Flix, J.; Fouz, M. C.; Garcia-Abia, P.; Lopez, O. Gonzalez; Lopez, S. Goy; Hernandez, J. M.; Josa, M. I.; De Martino, E. Navarro; Yzquierdo, A. Pérez-Calero; Pelayo, J. Puerta; Olmeda, A. Quintario; Redondo, I.; Romero, L.; Soares, M. S.; de Trocóniz, J. F.; Missiroli, M.; Moran, D.; Cuevas, J.; Erice, C.; Menendez, J. Fernandez; Caballero, I. Gonzalez; Fernández, J. R. González; Cortezon, E. Palencia; Cruz, S. Sanchez; Andrés, I. Suárez; Vischia, P.; Garcia, J. M. Vizan; Cabrillo, I. J.; Calderon, A.; Curras, E.; Fernandez, M.; Garcia-Ferrero, J.; Gomez, G.; Virto, A. Lopez; Marco, J.; Rivero, C. Martinez; Matorras, F.; Gomez, J. Piedra; Rodrigo, T.; RuizJimeno, A.; Scodellaro, L.; Trevisani, N.; Vila, I.; Cortabitarte, R. Vilar; Abbaneo, D.; Auffray, E.; Auzinger, G.; Baillon, P.; Ball, A. H.; Barney, D.; Bloch, P.; Bocci, A.; Botta, C.; Camporesi, T.; Castello, R.; Cepeda, M.; Cerminara, G.; Chen, Y.; Cimmino, A.; d'Enterria, D.; Dabrowski, A.; Daponte, V.; David, A.; De Gruttola, M.; De Roeck, A.; Di Marco, E.; Dobson, M.; Dorney, B.; du Pree, T.; Duggan, D.; Dünser, M.; Dupont, N.; Elliott-Peisert, A.; Everaerts, P.; Fartoukh, S.; Franzoni, G.; Fulcher, J.; Funk, W.; Gigi, D.; Gill, K.; Girone, M.; Glege, F.; Gulhan, D.; Gundacker, S.; Guthoff, M.; Harris, P.; Hegeman, J.; Innocente, V.; Janot, P.; Kieseler, J.; Kirschenmann, H.; Knünz, V.; Kornmayer, A.; Kortelainen, M. J.; Kousouris, K.; Krammer, M.; Lange, C.; Lecoq, P.; Lourenço, C.; Lucchini, M. T.; Malgeri, L.; Mannelli, M.; Martelli, A.; Meijers, F.; Merlin, J. A.; Mersi, S.; Meschi, E.; Milenovic, P.; Moortgat, F.; Morovic, S.; Mulders, M.; Neugebauer, H.; Orfanelli, S.; Orsini, L.; Pape, L.; Perez, E.; Peruzzi, M.; Petrilli, A.; Petrucciani, G.; Pfeiffer, A.; Pierini, M.; Racz, A.; Reis, T.; Rolandi, G.; Rovere, M.; Sakulin, H.; Sauvan, J. B.; Schäfer, C.; Schwick, C.; Seidel, M.; Sharma, A.; Silva, P.; Sphicas, P.; Steggemann, J.; Stoye, M.; Takahashi, Y.; Tosi, M.; Treille, D.; Triossi, A.; Tsirou, A.; Veckalns, V.; Veres, G. I.; Verweij, M.; Wardle, N.; Wöhri, H. K.; Zagozdzinska, A.; Zeuner, W. D.; Bertl, W.; Deiters, K.; Erdmann, W.; Horisberger, R.; Ingram, Q.; Kaestli, H. C.; Kotlinski, D.; Langenegger, U.; Rohe, T.; Wiederkehr, S. A.; Bachmair, F.; Bäni, L.; Bianchini, L.; Casal, B.; Dissertori, G.; Dittmar, M.; Donegà, M.; Grab, C.; Heidegger, C.; Hits, D.; Hoss, J.; Kasieczka, G.; Lustermann, W.; Mangano, B.; Marionneau, M.; del Arbol, P. Martinez Ruiz; Masciovecchio, M.; Meinhard, M. T.; Meister, D.; Micheli, F.; Musella, P.; Nessi-Tedaldi, F.; Pandolfi, F.; Pata, J.; Pauss, F.; Perrin, G.; Perrozzi, L.; Quittnat, M.; Rossini, M.; Schönenberger, M.; Starodumov, A.; Tavolaro, V. R.; Theofilatos, K.; Wallny, R.; Aarrestad, T. K.; Amsler, C.; Caminada, L.; Canelli, M. F.; De Cosa, A.; Donato, S.; Galloni, C.; Hinzmann, A.; Hreus, T.; Kilminster, B.; Ngadiuba, J.; Pinna, D.; Rauco, G.; Robmann, P.; Salerno, D.; Seitz, C.; Yang, Y.; Zucchetta, A.; Candelise, V.; Chen, C. W.; Doan, T. H.; Jain, Sh.; Khurana, R.; Konyushikhin, M.; Kuo, C. M.; Lin, W.; Lu, Y. J.; Pozdnyakov, A.; Tsai, F. Y.; Yu, S. S.; Kumar, Arun; Chang, P.; Chang, Y. H.; Chao, Y.; Chen, K. F.; Chen, P. H.; Fiori, F.; Hou, W.-S.; Hsiung, Y.; Liu, Y. F.; Lu, R.-S.; Moya, M. Miñano; Paganis, E.; Psallidas, A.; Tsai, J. f.; Asavapibhop, B.; Singh, G.; Srimanobhas, N.; Suwonjandee, N.; Adiguzel, A.; Bakirci, M. N.; Cerci, S.; Damarseckin, S.; Demiroglu, Z. S.; Dozen, C.; Dumanoglu, I.; Girgis, S.; Gokbulut, G.; Guler, Y.; Hos, I.; Kangal, E. E.; Kara, O.; Topaksu, A. Kayis; Kiminsu, U.; Oglakci, M.; Onengut, G.; Ozdemir, K.; Tali, B.; Turkcapar, S.; Zorbakir, I. S.; Zorbilmez, C.; Bilin, B.; Bilmis, S.; Isildak, B.; Karapinar, G.; Yalvac, M.; Zeyrek, M.; Gülmez, E.; Kaya, M.; Kaya, O.; Yetkin, E. A.; Yetkin, T.; Cakir, A.; Cankocak, K.; Sen, S.; Grynyov, B.; Levchuk, L.; Sorokin, P.; Aggleton, R.; Ball, F.; Beck, L.; Brooke, J. J.; Burns, D.; Clement, E.; Cussans, D.; Flacher, H.; Goldstein, J.; Grimes, M.; Heath, G. P.; Heath, H. F.; Jacob, J.; Kreczko, L.; Lucas, C.; Newbold, D. M.; Paramesvaran, S.; Poll, A.; Sakuma, T.; El Nasr-storey, S. Seif; Smith, D.; Smith, V. J.; Bell, K. W.; Belyaev, A.; Brew, C.; Brown, R. M.; Calligaris, L.; Cieri, D.; Cockerill, D. J. A.; Coughlan, J. A.; Harder, K.; Harper, S.; Olaiya, E.; Petyt, D.; Shepherd-Themistocleous, C. H.; Thea, A.; Tomalin, I. R.; Williams, T.; Baber, M.; Bainbridge, R.; Buchmuller, O.; Bundock, A.; Casasso, S.; Citron, M.; Colling, D.; Corpe, L.; Dauncey, P.; Davies, G.; De Wit, A.; Negra, M. Della; Di Maria, R.; Dunne, P.; Elwood, A.; Futyan, D.; Haddad, Y.; Hall, G.; Iles, G.; James, T.; Lane, R.; Laner, C.; Lyons, L.; Magnan, A.-M.; Malik, S.; Mastrolorenzo, L.; Nash, J.; Nikitenko, A.; Pela, J.; Penning, B.; Pesaresi, M.; Raymond, D. M.; Richards, A.; Rose, A.; Scott, E.; Seez, C.; Summers, S.; Tapper, A.; Uchida, K.; Acosta, M. Vazquez; Virdee, T.; Wright, J.; Zenz, S. C.; Cole, J. E.; Hobson, P. R.; Khan, A.; Kyberd, P.; Reid, I. D.; Symonds, P.; Teodorescu, L.; Turner, M.; Borzou, A.; Call, K.; Dittmann, J.; Hatakeyama, K.; Liu, H.; Pastika, N.; Bartek, R.; Dominguez, A.; Buccilli, A.; Cooper, S. I.; Henderson, C.; Rumerio, P.; West, C.; Arcaro, D.; Avetisyan, A.; Bose, T.; Gastler, D.; Rankin, D.; Richardson, C.; Rohlf, J.; Sulak, L.; Zou, D.; Benelli, G.; Cutts, D.; Garabedian, A.; Hakala, J.; Heintz, U.; Hogan, J. M.; Jesus, O.; Kwok, K. H. M.; Laird, E.; Landsberg, G.; Mao, Z.; Narain, M.; Piperov, S.; Sagir, S.; Spencer, E.; Syarif, R.; Breedon, R.; Burns, D.; De La Barca Sanchez, M. Calderon; Chauhan, S.; Chertok, M.; Conway, J.; Conway, R.; Cox, P. T.; Erbacher, R.; Flores, C.; Funk, G.; Gardner, M.; Ko, W.; Lander, R.; Mclean, C.; Mulhearn, M.; Pellett, D.; Pilot, J.; Shalhout, S.; Shi, M.; Smith, J.; Squires, M.; Stolp, D.; Tos, K.; Tripathi, M.; Bachtis, M.; Bravo, C.; Cousins, R.; Dasgupta, A.; Florent, A.; Hauser, J.; Ignatenko, M.; Mccoll, N.; Saltzberg, D.; Schnaible, C.; Valuev, V.; Weber, M.; Bouvier, E.; Burt, K.; Clare, R.; Ellison, J.; Gary, J. W.; Shirazi, S. M. A. Ghiasi; Hanson, G.; Heilman, J.; Jandir, P.; Kennedy, E.; Lacroix, F.; Long, O. R.; Negrete, M. Olmedo; Paneva, M. I.; Shrinivas, A.; Si, W.; Wei, H.; Wimpenny, S.; Yates, B. R.; Branson, J. G.; Cerati, G. B.; Cittolin, S.; Derdzinski, M.; Gerosa, R.; Holzner, A.; Klein, D.; Krutelyov, V.; Letts, J.; Macneill, I.; Olivito, D.; Padhi, S.; Pieri, M.; Sani, M.; Sharma, V.; Simon, S.; Tadel, M.; Vartak, A.; Wasserbaech, S.; Welke, C.; Wood, J.; Würthwein, F.; Yagil, A.; Porta, G. Zevi Della; Amin, N.; Bhandari, R.; Bradmiller-Feld, J.; Campagnari, C.; Dishaw, A.; Dutta, V.; Sevilla, M. Franco; George, C.; Golf, F.; Gouskos, L.; Gran, J.; Heller, R.; Incandela, J.; Mullin, S. D.; Ovcharova, A.; Qu, H.; Richman, J.; Stuart, D.; Suarez, I.; Yoo, J.; Anderson, D.; Bendavid, J.; Bornheim, A.; Bunn, J.; Duarte, J.; Lawhorn, J. M.; Mott, A.; Newman, H. B.; Pena, C.; Spiropulu, M.; Vlimant, J. R.; Xie, S.; Zhu, R. Y.; Andrews, M. B.; Ferguson, T.; Paulini, M.; Russ, J.; Sun, M.; Vogel, H.; Vorobiev, I.; Weinberg, M.; Cumalat, J. P.; Ford, W. T.; Jensen, F.; Johnson, A.; Krohn, M.; Leontsinis, S.; Mulholland, T.; Stenson, K.; Wagner, S. R.; Alexander, J.; Chaves, J.; Chu, J.; Dittmer, S.; Mcdermott, K.; Mirman, N.; Patterson, J. R.; Rinkevicius, A.; Ryd, A.; Skinnari, L.; Soffi, L.; Tan, S. M.; Tao, Z.; Thom, J.; Tucker, J.; Wittich, P.; Zientek, M.; Winn, D.; Abdullin, S.; Albrow, M.; Apollinari, G.; Apresyan, A.; Banerjee, S.; Bauerdick, L. A. T.; Beretvas, A.; Berryhill, J.; Bhat, P. C.; Bolla, G.; Burkett, K.; Butler, J. N.; Cheung, H. W. K.; Chlebana, F.; Cihangir, S.; Cremonesi, M.; Elvira, V. D.; Fisk, I.; Freeman, J.; Gottschalk, E.; Gray, L.; Green, D.; Grünendahl, S.; Gutsche, O.; Hare, D.; Harris, R. M.; Hasegawa, S.; Hirschauer, J.; Hu, Z.; Jayatilaka, B.; Jindariani, S.; Johnson, M.; Joshi, U.; Klima, B.; Kreis, B.; Lammel, S.; Linacre, J.; Lincoln, D.; Lipton, R.; Liu, M.; Liu, T.; De Sá, R. Lopes; Lykken, J.; Maeshima, K.; Magini, N.; Marraffino, J. M.; Maruyama, S.; Mason, D.; McBride, P.; Merkel, P.; Mrenna, S.; Nahn, S.; O'Dell, V.; Pedro, K.; Prokofyev, O.; Rakness, G.; Ristori, L.; Sexton-Kennedy, E.; Soha, A.; Spalding, W. J.; Spiegel, L.; Stoynev, S.; Strait, J.; Strobbe, N.; Taylor, L.; Tkaczyk, S.; Tran, N. V.; Uplegger, L.; Vaandering, E. W.; Vernieri, C.; Verzocchi, M.; Vidal, R.; Wang, M.; Weber, H. A.; Whitbeck, A.; Wu, Y.; Acosta, D.; Avery, P.; Bortignon, P.; Bourilkov, D.; Brinkerhoff, A.; Carnes, A.; Carver, M.; Curry, D.; Das, S.; Field, R. D.; Furic, I. K.; Konigsberg, J.; Korytov, A.; Low, J. F.; Ma, P.; Matchev, K.; Mei, H.; Mitselmakher, G.; Rank, D.; Shchutska, L.; Sperka, D.; Thomas, L.; Wang, J.; Wang, S.; Yelton, J.; Linn, S.; Markowitz, P.; Martinez, G.; Rodriguez, J. L.; Ackert, A.; Adams, T.; Askew, A.; Bein, S.; Hagopian, S.; Hagopian, V.; Johnson, K. F.; Kolberg, T.; Perry, T.; Prosper, H.; Santra, A.; Yohay, R.; Baarmand, M. M.; Bhopatkar, V.; Colafranceschi, S.; Hohlmann, M.; Noonan, D.; Roy, T.; Yumiceva, F.; Adams, M. R.; Apanasevich, L.; Berry, D.; Betts, R. R.; Cavanaugh, R.; Chen, X.; Evdokimov, O.; Gerber, C. E.; Hangal, D. A.; Hofman, D. J.; Jung, K.; Kamin, J.; Gonzalez, I. D. Sandoval; Trauger, H.; Varelas, N.; Wang, H.; Wu, Z.; Zakaria, M.; Zhang, J.; Bilki, B.; Clarida, W.; Dilsiz, K.; Durgut, S.; Gandrajula, R. P.; Haytmyradov, M.; Khristenko, V.; Merlo, J.-P.; Mermerkaya, H.; Mestvirishvili, A.; Moeller, A.; Nachtman, J.; Ogul, H.; Onel, Y.; Ozok, F.; Penzo, A.; Snyder, C.; Tiras, E.; Wetzel, J.; Yi, K.; Blumenfeld, B.; Cocoros, A.; Eminizer, N.; Fehling, D.; Feng, L.; Gritsan, A. V.; Maksimovic, P.; Roskes, J.; Sarica, U.; Swartz, M.; Xiao, M.; You, C.; Al-bataineh, A.; Baringer, P.; Bean, A.; Boren, S.; Bowen, J.; Castle, J.; Forthomme, L.; Khalil, S.; Kropivnitskaya, A.; Majumder, D.; Mcbrayer, W.; Murray, M.; Sanders, S.; Stringer, R.; Takaki, J. D. Tapia; Wang, Q.; Ivanov, A.; Kaadze, K.; Maravin, Y.; Mohammadi, A.; Saini, L. K.; Skhirtladze, N.; Toda, S.; Rebassoo, F.; Wright, D.; Anelli, C.; Baden, A.; Baron, O.; Belloni, A.; Calvert, B.; Eno, S. C.; Ferraioli, C.; Gomez, J. A.; Hadley, N. J.; Jabeen, S.; Jeng, G. Y.; Kellogg, R. G.; Kunkle, J.; Mignerey, A. C.; Ricci-Tam, F.; Shin, Y. H.; Skuja, A.; Tonjes, M. B.; Tonwar, S. C.; Abercrombie, D.; Allen, B.; Apyan, A.; Azzolini, V.; Barbieri, R.; Baty, A.; Bi, R.; Bierwagen, K.; Brandt, S.; Busza, W.; Cali, I. A.; D'Alfonso, M.; Demiragli, Z.; Ceballos, G. Gomez; Goncharov, M.; Hsu, D.; Iiyama, Y.; Innocenti, G. M.; Klute, M.; Kovalskyi, D.; Krajczar, K.; Lai, Y. S.; Lee, Y.-J.; Levin, A.; Luckey, P. D.; Maier, B.; Marini, A. C.; Mcginn, C.; Mironov, C.; Narayanan, S.; Niu, X.; Paus, C.; Roland, C.; Roland, G.; Salfeld-Nebgen, J.; Stephans, G. S. F.; Tatar, K.; Velicanu, D.; Wang, J.; Wang, T. W.; Wyslouch, B.; Benvenuti, A. C.; Chatterjee, R. M.; Evans, A.; Hansen, P.; Kalafut, S.; Kao, S. C.; Kubota, Y.; Lesko, Z.; Mans, J.; Nourbakhsh, S.; Ruckstuhl, N.; Rusack, R.; Tambe, N.; Turkewitz, J.; Acosta, J. G.; Oliveros, S.; Avdeeva, E.; Bloom, K.; Claes, D. R.; Fangmeier, C.; Suarez, R. Gonzalez; Kamalieddin, R.; Kravchenko, I.; Rodrigues, A. Malta; Monroy, J.; Siado, J. E.; Snow, G. R.; Stieger, B.; Alyari, M.; Dolen, J.; Godshalk, A.; Harrington, C.; Iashvili, I.; Kaisen, J.; Nguyen, D.; Parker, A.; Rappoccio, S.; Roozbahani, B.; Alverson, G.; Barberis, E.; Hortiangtham, A.; Massironi, A.; Morse, D. M.; Nash, D.; Orimoto, T.; De Lima, R. Teixeira; Trocino, D.; Wang, R.-J.; Wood, D.; Bhattacharya, S.; Charaf, O.; Hahn, K. A.; Mucia, N.; Odell, N.; Pollack, B.; Schmitt, M. H.; Sung, K.; Trovato, M.; Velasco, M.; Dev, N.; Hildreth, M.; Anampa, K. Hurtado; Jessop, C.; Karmgard, D. J.; Kellams, N.; Lannon, K.; Marinelli, N.; Meng, F.; Mueller, C.; Musienko, Y.; Planer, M.; Reinsvold, A.; Ruchti, R.; Rupprecht, N.; Smith, G.; Taroni, S.; Wayne, M.; Wolf, M.; Woodard, A.; Alimena, J.; Antonelli, L.; Bylsma, B.; Durkin, L. S.; Flowers, S.; Francis, B.; Hart, A.; Hill, C.; Ji, W.; Liu, B.; Luo, W.; Puigh, D.; Winer, B. L.; Wulsin, H. W.; Cooperstein, S.; Driga, O.; Elmer, P.; Hardenbrook, J.; Hebda, P.; Lange, D.; Luo, J.; Marlow, D.; Medvedeva, T.; Mei, K.; Ojalvo, I.; Olsen, J.; Palmer, C.; Piroué, P.; Stickland, D.; Svyatkovskiy, A.; Tully, C.; Malik, S.; Barker, A.; Barnes, V. E.; Folgueras, S.; Gutay, L.; Jha, M. K.; Jones, M.; Jung, A. W.; Khatiwada, A.; Miller, D. H.; Neumeister, N.; Schulte, J. F.; Shi, X.; Sun, J.; Wang, F.; Xie, W.; Parashar, N.; Stupak, J.; Adair, A.; Akgun, B.; Chen, Z.; Ecklund, K. M.; Geurts, F. J. M.; Guilbaud, M.; Li, W.; Michlin, B.; Northup, M.; Padley, B. P.; Roberts, J.; Rorie, J.; Tu, Z.; Zabel, J.; Betchart, B.; Bodek, A.; de Barbaro, P.; Demina, R.; Duh, Y. t.; Ferbel, T.; Galanti, M.; Garcia-Bellido, A.; Han, J.; Hindrichs, O.; Khukhunaishvili, A.; Lo, K. H.; Tan, P.; Verzetti, M.; Agapitos, A.; Chou, J. P.; Gershtein, Y.; Espinosa, T. A. Gómez; Halkiadakis, E.; Heindl, M.; Hughes, E.; Kaplan, S.; Elayavalli, R. Kunnawalkam; Kyriacou, S.; Lath, A.; Montalvo, R.; Nash, K.; Osherson, M.; Saka, H.; Salur, S.; Schnetzer, S.; Sheffield, D.; Somalwar, S.; Stone, R.; Thomas, S.; Thomassen, P.; Walker, M.; Delannoy, A. G.; Foerster, M.; Heideman, J.; Riley, G.; Rose, K.; Spanier, S.; Thapa, K.; Bouhali, O.; Celik, A.; Dalchenko, M.; De Mattia, M.; Delgado, A.; Dildick, S.; Eusebi, R.; Gilmore, J.; Huang, T.; Juska, E.; Kamon, T.; Mueller, R.; Pakhotin, Y.; Patel, R.; Perloff, A.; Perniè, L.; Rathjens, D.; Safonov, A.; Tatarinov, A.; Ulmer, K. A.; Akchurin, N.; Damgov, J.; De Guio, F.; Dragoiu, C.; Dudero, P. R.; Faulkner, J.; Gurpinar, E.; Kunori, S.; Lamichhane, K.; Lee, S. W.; Libeiro, T.; Peltola, T.; Undleeb, S.; Volobouev, I.; Wang, Z.; Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Sheldon, P.; Tuo, S.; Velkovska, J.; Xu, Q.; Arenton, M. W.; Barria, P.; Cox, B.; Hirosky, R.; Ledovskoy, A.; Li, H.; Neu, C.; Sinthuprasith, T.; Sun, X.; Wang, Y.; Wolfe, E.; Xia, F.; Clarke, C.; Harr, R.; Karchin, P. E.; Sturdy, J.; Zaleski, S.; Belknap, D. A.; Buchanan, J.; Caillol, C.; Dasu, S.; Dodd, L.; Duric, S.; Gomber, B.; Grothe, M.; Herndon, M.; Hervé, A.; Hussain, U.; Klabbers, P.; Lanaro, A.; Levine, A.; Long, K.; Loveless, R.; Pierro, G. A.; Polese, G.; Ruggles, T.; Savin, A.; Smith, N.; Smith, W. H.; Taylor, D.; Woods, N.

2017-10-01

A search for dark matter is performed looking for events with large missing transverse momentum and a Higgs boson decaying either to a pair of bottom quarks or to a pair of photons. The data from proton-proton collisions at a center-of-mass energy of 13 TeV, collected in 2015 with the CMS detector at the LHC, correspond to an integrated luminosity of 2.3 fb-1. Results are interpreted in the context of a Z'-two-Higgs-doublet model, where the gauge symmetry of the standard model is extended by a U(1)Z ' group, with a new massive Z' gauge boson, and the Higgs sector is extended with four additional Higgs bosons. In this model, a high-mass resonance Z' decays into a pseudoscalar boson A and a light SM-like scalar Higgs boson, and the A decays to a pair of dark matter particles. No significant excesses are observed over the background prediction. Combining results from the two decay channels yields exclusion limits in the signal cross section in the m Z ' - m A phase space. For example, the observed data exclude the Z' mass range from 600 to 1860 GeV, for Z' coupling strength g Z ' = 0.8, the coupling of A with dark matter particles g χ = 1, the ratio of the vacuum expectation values tan β = 1, and m A = 300 GeV. The results of this analysis are valid for any dark matter particle mass below 100 GeV. [Figure not available: see fulltext.

Static and dynamic properties of heavily doped quantum vortices

NASA Astrophysics Data System (ADS)

Pshenichnyuk, I. A.

2017-10-01

Quantum vortices in superfluids may capture matter and deposit it inside their core. By doping vortices with foreign particles one can effectively visualize them and study them experimentally. To acquire a better understanding of the interaction between quantum vortices and matter, and clarify the details of recent experiments, the properties of doped vortices are investigated here theoretically in the regimes where the doping mass becomes close to the total mass of superfluid particles forming a vortex. Such formations are dynamically stable and, possessing both vorticity and enhanced inertia, demonstrate properties that are different from the pure vortex case. The goal of this paper is to define and investigate the universal aspects of heavily doped vortex behavior, which can be realized in different types of quantum mixtures. The proposed 3D model is based on a system of coupled semiclassical matter wave equations that are solved numerically in a wide range of physical parameters. The size, geometry and binding energy of dopants in different regimes are discussed. The coupled motion of a vortex-dopant complex and decoupling conditions are studied. The reconnection of vortices, taken as an example of a fundamental process responsible for the evolution of a quantum turbulent state, is modeled to illustrate the difference between the light and heavy doping cases.

Cavity QED with hybrid nanocircuits: from atomic-like physics to condensed matter phenomena

NASA Astrophysics Data System (ADS)

Cottet, Audrey; Dartiailh, Matthieu C.; Desjardins, Matthieu M.; Cubaynes, Tino; Contamin, Lauriane C.; Delbecq, Matthieu; Viennot, Jérémie J.; Bruhat, Laure E.; Douçot, Benoit; Kontos, Takis

2017-11-01

Circuit QED techniques have been instrumental in manipulating and probing with exquisite sensitivity the quantum state of superconducting quantum bits coupled to microwave cavities. Recently, it has become possible to fabricate new devices in which the superconducting quantum bits are replaced by hybrid mesoscopic circuits combining nanoconductors and metallic reservoirs. This mesoscopic QED provides a new experimental playground to study the light-matter interaction in electronic circuits. Here, we present the experimental state of the art of mesoscopic QED and its theoretical description. A first class of experiments focuses on the artificial atom limit, where some quasiparticles are trapped in nanocircuit bound states. In this limit, the circuit QED techniques can be used to manipulate and probe electronic degrees of freedom such as confined charges, spins, or Andreev pairs. A second class of experiments uses cavity photons to reveal the dynamics of electron tunneling between a nanoconductor and fermionic reservoirs. For instance, the Kondo effect, the charge relaxation caused by grounded metallic contacts, and the photo-emission caused by voltage-biased reservoirs have been studied. The tunnel coupling between nanoconductors and fermionic reservoirs also enable one to obtain split Cooper pairs, or Majorana bound states. Cavity photons represent a qualitatively new tool to study these exotic condensed matter states.

Cavity QED with hybrid nanocircuits: from atomic-like physics to condensed matter phenomena.

PubMed

Cottet, Audrey; Dartiailh, Matthieu C; Desjardins, Matthieu M; Cubaynes, Tino; Contamin, Lauriane C; Delbecq, Matthieu; Viennot, Jérémie J; Bruhat, Laure E; Douçot, Benoit; Kontos, Takis

2017-11-01

Circuit QED techniques have been instrumental in manipulating and probing with exquisite sensitivity the quantum state of superconducting quantum bits coupled to microwave cavities. Recently, it has become possible to fabricate new devices in which the superconducting quantum bits are replaced by hybrid mesoscopic circuits combining nanoconductors and metallic reservoirs. This mesoscopic QED provides a new experimental playground to study the light-matter interaction in electronic circuits. Here, we present the experimental state of the art of mesoscopic QED and its theoretical description. A first class of experiments focuses on the artificial atom limit, where some quasiparticles are trapped in nanocircuit bound states. In this limit, the circuit QED techniques can be used to manipulate and probe electronic degrees of freedom such as confined charges, spins, or Andreev pairs. A second class of experiments uses cavity photons to reveal the dynamics of electron tunneling between a nanoconductor and fermionic reservoirs. For instance, the Kondo effect, the charge relaxation caused by grounded metallic contacts, and the photo-emission caused by voltage-biased reservoirs have been studied. The tunnel coupling between nanoconductors and fermionic reservoirs also enable one to obtain split Cooper pairs, or Majorana bound states. Cavity photons represent a qualitatively new tool to study these exotic condensed matter states.

Orientational alignment in cavity quantum electrodynamics

NASA Astrophysics Data System (ADS)

Keeling, Jonathan; Kirton, Peter G.

2018-05-01

We consider the orientational alignment of dipoles due to strong matter-light coupling for a nonvanishing density of excitations. We compare various approaches to this problem in the limit of large numbers of emitters and show that direct Monte Carlo integration, mean-field theory, and large deviation methods match exactly in this limit. All three results show that orientational alignment develops in the presence of a macroscopically occupied polariton mode and that the dipoles asymptotically approach perfect alignment in the limit of high density or low temperature.

New insights on the matter-gravity coupling paradigm.

PubMed

Delsate, Térence; Steinhoff, Jan

2012-07-13

The coupling between matter and gravity in general relativity is given by a proportionality relation between the stress tensor and the geometry. This is an oriented assumption driven by the fact that both the stress tensor and the Einstein tensor are divergenceless. However, general relativity is in essence a nonlinear theory, so there is no obvious reason why the coupling to matter should be linear. On another hand, modified theories of gravity usually affect the vacuum dynamics, yet keep the coupling to matter linear. In this Letter, we address the implications of consistent nonlinear gravity-matter coupling. The Eddington-inspired Born-Infeld theory recently introduced by Bañados and Ferreira provides an enlightening realization of such coupling modifications. We find that this theory coupled to a perfect fluid reduces to general relativity coupled to a nonlinearly modified perfect fluid, leading to an ambiguity between modified coupling and modified equation of state. We discuss observational consequences of this degeneracy and argue that such a completion of general relativity is viable from both an experimental and theoretical point of view through energy conditions, consistency, and singularity-avoidance perspectives. We use these results to discuss the impact of changing the coupling paradigm.

Neutralino dark matter in the left-right supersymmetric model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Demir, Durmus A.; Frank, Mariana; Turan, Ismail

2006-06-01

We study the neutralino sector of the left-right supersymmetric model. In addition to the possibilities available in the minimal supersymmetric model, the neutralino states can be superpartners of the U(1){sub B-L} gauge boson, the neutral SU(2){sub R} gauge boson, or of the Higgs triplets. We analyze neutralino masses and determine the parameter regions for which the lightest neutralino can be one of the new pure states. We then calculate the relic density of the dark matter for each of these states and impose the constraints coming from the {rho} parameter, the anomalous magnetic moment of the muon, b{yields}s{gamma}, as wellmore » as general supersymmetric mass bounds. The lightest neutralino can be the bino, or the right-wino, or the neutral triplet Higgsino, all of which have different couplings to the standard model particles from the usual neutralinos. A light bino satisfies all the experimental constraints and would be the preferred dark matter candidate for light supersymmetric scalar masses, while the right-wino would be favored by intermediate supersymmetric mass scales. The neutral triplet Higgs fermion satisfies the experimental bounds only in a small region of the parameter space, for intermediate to heavy supersymmetric scalar masses.« less

Stomatal conductance of lettuce grown under or exposed to different light qualities

NASA Technical Reports Server (NTRS)

Kim, Hyeon-Hye; Goins, Gregory D.; Wheeler, Raymond M.; Sager, John C.

2004-01-01

BACKGROUND AND AIMS: The objective of this research was to examine the effects of differences in light spectrum on the stomatal conductance (Gs) and dry matter production of lettuce plants grown under a day/night cycle with different spectra, and also the effects on Gs of short-term exposure to different spectra. METHODS: Lettuce (Lactuca sativa) plants were grown with 6 h dark and 18 h light under four different spectra, red-blue (RB), red-blue-green (RBG), green (GF) and white (CWF), and Gs and plant growth were measured. KEY RESULTS AND CONCLUSIONS: Conductance of plants grown for 23 d under CWF rose rapidly on illumination to a maximum in the middle of the light period, then decreased again before the dark period when it was minimal. However, the maximum was smaller in plants grown under RB, RGB and GF. This demonstrates that spectral quality during growth affects the diurnal pattern of stomatal conductance. Although Gs was smaller in plants grown under RGB than CWF, dry mass accumulation was greater, suggesting that Gs did not limit carbon assimilation under these spectral conditions. Temporarily changing the spectral quality of the plants grown for 23 d under CWF, affected stomatal responses reversibly, confirming studies on epidermal strips. This study provides new information showing that Gs is responsive to spectral quality during growth and, in the short-term, is not directly coupled to dry matter accumulation.

Cosmological Higgs-Axion Interplay for a Naturally Small Electroweak Scale.

PubMed

Espinosa, J R; Grojean, C; Panico, G; Pomarol, A; Pujolàs, O; Servant, G

2015-12-18

Recently, a new mechanism to generate a naturally small electroweak scale has been proposed. It exploits the coupling of the Higgs boson to an axionlike field and a long era in the early Universe where the axion unchains a dynamical screening of the Higgs mass. We present a new realization of this idea with the new feature that it leaves no sign of new physics at the electroweak scale, and up to a rather large scale, 10^{9}  GeV, except for two very light and weakly coupled axionlike states. One of the scalars can be a viable dark matter candidate. Such a cosmological Higgs-axion interplay could be tested with a number of experimental strategies.

Interacting vector fields in relativity without relativity

NASA Astrophysics Data System (ADS)

Anderson, Edward; Barbour, Julian

2002-06-01

Barbour, Foster and Ó Murchadha have recently developed a new framework, called here the 3-space approach, for the formulation of classical bosonic dynamics. Neither time nor a locally Minkowskian structure of spacetime are presupposed. Both arise as emergent features of the world from geodesic-type dynamics on a space of three-dimensional metric-matter configurations. In fact gravity, the universal light-cone and Abelian gauge theory minimally coupled to gravity all arise naturally through a single common mechanism. It yields relativity - and more - without presupposing relativity. This paper completes the recovery of the presently known bosonic sector within the 3-space approach. We show, for a rather general ansatz, that 3-vector fields can interact among themselves only as Yang-Mills fields minimally coupled to gravity.

Nonlinear dynamics and cavity cooling of levitated nanoparticles

NASA Astrophysics Data System (ADS)

Fonseca, P. Z. G.; Aranas, E. B.; Millen, J.; Monteiro, T. S.; Barker, P. F.

2016-09-01

We investigate a dynamic nonlinear optomechanical system, comprising a nanosphere levitated in a hybrid electro-optical trap. An optical cavity offers readout of both linear-in-position and quadratic-in-position (nonlinear) light-matter coupling, whilst simultaneously cooling the nanosphere, for indefinite periods of time and in high vacuum. Through the rich sideband structure displayed by the cavity output we can observe cooling of the linear and non-linear particle's motion. Here we present an experimental setup which allows full control over the cavity resonant frequencies, and shows cooling of the particle's motion as a function of the detuning. This work paves the way to strong-coupled quantum dynamics between a cavity and a mesoscopic object largely decoupled from its environment.

Near-infrared exciton-polaritons in strongly coupled single-walled carbon nanotube microcavities

NASA Astrophysics Data System (ADS)

Graf, Arko; Tropf, Laura; Zakharko, Yuriy; Zaumseil, Jana; Gather, Malte C.

2016-10-01

Exciton-polaritons form upon strong coupling between electronic excitations of a material and photonic states of a surrounding microcavity. In organic semiconductors the special nature of excited states leads to particularly strong coupling and facilitates condensation of exciton-polaritons at room temperature, which may lead to electrically pumped organic polariton lasers. However, charge carrier mobility and photo-stability in currently used materials is limited and exciton-polariton emission so far has been restricted to visible wavelengths. Here, we demonstrate strong light-matter coupling in the near infrared using single-walled carbon nanotubes (SWCNTs) in a polymer matrix and a planar metal-clad cavity. By exploiting the exceptional oscillator strength and sharp excitonic transition of (6,5) SWCNTs, we achieve large Rabi splitting (>110 meV), efficient polariton relaxation and narrow band emission (<15 meV). Given their high charge carrier mobility and excellent photostability, SWCNTs represent a promising new avenue towards practical exciton-polariton devices operating at telecommunication wavelengths.

Surface Plasmon Enhanced Strong Exciton-Photon Coupling in Hybrid Inorganic-Organic Perovskite Nanowires.

PubMed

Shang, Qiuyu; Zhang, Shuai; Liu, Zhen; Chen, Jie; Yang, Pengfei; Li, Chun; Li, Wei; Zhang, Yanfeng; Xiong, Qihua; Liu, Xinfeng; Zhang, Qing

2018-06-13

Manipulating strong light-matter interaction in semiconductor microcavities is crucial for developing high-performance exciton polariton devices with great potential in next-generation all-solid state quantum technologies. In this work, we report surface plasmon enhanced strong exciton-photon interaction in CH 3 NH 3 PbBr 3 perovskite nanowires. Characteristic anticrossing behaviors, indicating a Rabi splitting energy up to ∼564 meV, are observed near exciton resonance in hybrid perovskite nanowire/SiO 2 /Ag cavity at room temperature. The exciton-photon coupling strength is enhanced by ∼35% on average, which is mainly attributed to surface plasmon induced localized excitation field redistribution. Further, systematic studies on SiO 2 thickness and nanowire dimension dependence of exciton-photon interaction are presented. These results provide new avenues to achieve extremely high coupling strengths and push forward the development of electrically pumped and ultralow threshold small lasers.

Manipulating Energy Flow at the Nanoscale by Coupling Plasmons of Metal Nanostructures to Resonant Molecules

NASA Astrophysics Data System (ADS)

Wiederrecht, Gary

2014-03-01

Collective hybrid excitations resulting from the coupling of metal nanostructures with organic molecules present unique opportunities for manipulating light-matter interactions at the nanoscale. In this talk, I discuss recent studies that are examples of the breadth of phenomena that are possible. First, the interactions of coupled plasmonic nanostructures with azobenzene-based polymers are described, in which the spatial features of the plasmonic near-field can be used to manipulate molecular motion. The directional molecular transport that results is shown to be useful for imaging the spatial and polarization features of the optical near-field. The modeling of this effect is described. Second, the coupling of excitonic molecular aggregates to metal nanostructures produces coherent coupling that provides added structure to the optical extinction spectra of metal nanoparticles, thereby by providing a photonic handle with which to manipulate energy flow on an ultrafast timescale. Monitoring the rate of energy flow as a function of photon energy reveals important information about the energy dissipation channels and the structural interactions between molecule and metal. Third, the strongly enhanced optical nonlinearity resulting from coupled plasmonic nanorods is described. The closely spaced nanorod material exhibits nonlocality of the optical response that has an unusually strong nonlinear dependence on incident light intensity. Electromagnetic modeling confirms the nonlocal response of the plasmonic metamaterial. The broader impact of collective hybrid excitations on nanophotonics applications is described. Use of the Center for Nanoscale Materials was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-06CH11357.

Nonlinear propagation of light in Dirac matter.

PubMed

Eliasson, Bengt; Shukla, P K

2011-09-01

The nonlinear interaction between intense laser light and a quantum plasma is modeled by a collective Dirac equation coupled with the Maxwell equations. The model is used to study the nonlinear propagation of relativistically intense laser light in a quantum plasma including the electron spin-1/2 effect. The relativistic effects due to the high-intensity laser light lead, in general, to a downshift of the laser frequency, similar to a classical plasma where the relativistic mass increase leads to self-induced transparency of laser light and other associated effects. The electron spin-1/2 effects lead to a frequency upshift or downshift of the electromagnetic (EM) wave, depending on the spin state of the plasma and the polarization of the EM wave. For laboratory solid density plasmas, the spin-1/2 effects on the propagation of light are small, but they may be significant in superdense plasma in the core of white dwarf stars. We also discuss extensions of the model to include kinetic effects of a distribution of the electrons on the nonlinear propagation of EM waves in a quantum plasma.

Coupled intertwiner dynamics: A toy model for coupling matter to spin foam models

NASA Astrophysics Data System (ADS)

Steinhaus, Sebastian

2015-09-01

The universal coupling of matter and gravity is one of the most important features of general relativity. In quantum gravity, in particular spin foams, matter couplings have been defined in the past, yet the mutual dynamics, in particular if matter and gravity are strongly coupled, are hardly explored, which is related to the definition of both matter and gravitational degrees of freedom on the discretization. However, extracting these mutual dynamics is crucial in testing the viability of the spin foam approach and also establishing connections to other discrete approaches such as lattice gauge theories. Therefore, we introduce a simple two-dimensional toy model for Yang-Mills coupled to spin foams, namely an Ising model coupled to so-called intertwiner models defined for SU (2 )k. The two systems are coupled by choosing the Ising coupling constant to depend on spin labels of the background, as these are interpreted as the edge lengths of the discretization. We coarse grain this toy model via tensor network renormalization and uncover an interesting dynamics: the Ising phase transition temperature turns out to be sensitive to the background configurations and conversely, the Ising model can induce phase transitions in the background. Moreover, we observe a strong coupling of both systems if close to both phase transitions.

Quantum formulation for nanoscale optical and material chirality: symmetry issues, space and time parity, and observables

NASA Astrophysics Data System (ADS)

Andrews, D. L.

2018-03-01

To properly represent the interplay and coupling of optical and material chirality at the photon-molecule or photon-nanoparticle level invites a recognition of quantum facets in the fundamental aspects and mechanisms of light-matter interaction. It is therefore appropriate to cast theory in a general quantum form, one that is applicable to both linear and nonlinear optics as well as various forms of chiroptical interaction including chiral optomechanics. Such a framework, fully accounting for both radiation and matter in quantum terms, facilitates the scrutiny and identification of key issues concerning spatial and temporal parity, scale, dissipation and measurement. Furthermore it fully provides for describing the interactions of structured or twisted light beams with a vortex character, and it leads to the complete identification of symmetry conditions for materials to provide for chiral discrimination. Quantum considerations also lend a distinctive perspective to the very different senses in which other aspects of chirality are recognized in metamaterials. Duly attending to the symmetry principles governing allowed or disallowed forms of chiral discrimination supports an objective appraisal of the experimental possibilities and developing applications.

Tunable room-temperature spin-selective optical Stark effect in solution-processed layered halide perovskites.

PubMed

Giovanni, David; Chong, Wee Kiang; Dewi, Herlina Arianita; Thirumal, Krishnamoorthy; Neogi, Ishita; Ramesh, Ramamoorthy; Mhaisalkar, Subodh; Mathews, Nripan; Sum, Tze Chien

2016-06-01

Ultrafast spin manipulation for opto-spin logic applications requires material systems that have strong spin-selective light-matter interaction. Conventional inorganic semiconductor nanostructures [for example, epitaxial II to VI quantum dots and III to V multiple quantum wells (MQWs)] are considered forerunners but encounter challenges such as lattice matching and cryogenic cooling requirements. Two-dimensional halide perovskite semiconductors, combining intrinsic tunable MQW structures and large oscillator strengths with facile solution processability, can offer breakthroughs in this area. We demonstrate novel room-temperature, strong ultrafast spin-selective optical Stark effect in solution-processed (C6H4FC2H4NH3)2PbI4 perovskite thin films. Exciton spin states are selectively tuned by ~6.3 meV using circularly polarized optical pulses without any external photonic cavity (that is, corresponding to a Rabi energy of ~55 meV and equivalent to applying a 70 T magnetic field), which is much larger than any conventional system. The facile halide and organic replacement in these perovskites affords control of the dielectric confinement and thus presents a straightforward strategy for tuning light-matter coupling strength.

Storage of RF photons in minimal conditions

NASA Astrophysics Data System (ADS)

Cromières, J.-P.; Chanelière, T.

2018-02-01

We investigate the minimal conditions to store coherently a RF pulse in a material medium. We choose a commercial quartz as a memory support because it is a widely available component with a high Q-factor. Pulse storage is obtained by varying dynamically the light-matter coupling with an analog switch. This parametric driving of the quartz dynamics can be alternatively interpreted as a stopped-light experiment. We obtain an efficiency of 26%, a storage time of 209 μs and a time-to-bandwidth product of 98 by optimizing the pulse temporal shape. The coherent character of the storage is demonstrated. Our goal is to connect different types of memories in the RF and optical domain for quantum information processing. Our motivation is essentially fundamental.

Strong-field adiabatic passage in the continuum: Electromagnetically induced transparency and stimulated Raman adiabatic passage

NASA Astrophysics Data System (ADS)

Eilam, A.; Shapiro, M.

2012-01-01

We present a fully quantum-mechanical theory of the mutual light-matter effects when two laser pulses interact with three discrete states coupled to a (quasi)continuum. Our formulation uses a single set of equations to describe the time dependence of the discrete and continuum populations, as well as pulse propagation in electromagnetically induced transparency (EIT) and stimulated Raman adiabatic passage (STIRAP) situations, for both weak and strong laser pulses. The theory gives a mechanistic picture of the “slowing down of light” and the state of spontaneously emitted photons during this process. Surprising features regarding the time dependence of material and radiative transients as well as limitations on quantum light storage and retrieval are unraveled.

Application of an extended random-phase approximation to giant resonances in light-, medium-, and heavy-mass nuclei

NASA Astrophysics Data System (ADS)

Tselyaev, V.; Lyutorovich, N.; Speth, J.; Krewald, S.; Reinhard, P.-G.

2016-09-01

We present results of the time blocking approximation (TBA) for giant resonances in light-, medium-, and heavy-mass nuclei. The TBA is an extension of the widely used random-phase approximation (RPA) adding complex configurations by coupling to phonon excitations. A new method for handling the single-particle continuum is developed and applied in the present calculations. We investigate in detail the dependence of the numerical results on the size of the single-particle space and the number of phonons as well as on nuclear matter properties. Our approach is self-consistent, based on an energy-density functional of Skyrme type where we used seven different parameter sets. The numerical results are compared with experimental data.

No slip gravity

NASA Astrophysics Data System (ADS)

Linder, Eric V.

2018-03-01

A subclass of the Horndeski modified gravity theory we call No Slip Gravity has particularly interesting properties: 1) a speed of gravitational wave propagation equal to the speed of light, 2) equality between the effective gravitational coupling strengths to matter and light, Gmatter and Glight, hence no slip between the metric potentials, yet difference from Newton's constant, and 3) suppressed growth to give better agreement with galaxy clustering observations. We explore the characteristics and implications of this theory, and project observational constraints. We also give a simple expression for the ratio of the gravitational wave standard siren distance to the photon standard candle distance, in this theory and others, and enable a direct comparison of modified gravity in structure growth and in gravitational waves, an important crosscheck.

Full Stark control of polariton states on a spin-orbit hypersphere

NASA Astrophysics Data System (ADS)

Li, Feng; Cancellieri, E.; Buonaiuto, G.; Skolnick, M. S.; Krizhanovskii, D. N.; Whittaker, D. M.

2016-11-01

The orbital angular momentum and the polarization of light are physical quantities widely investigated for classical and quantum information processing. In this work we propose to take advantage of strong light-matter coupling, circular-symmetric confinement, and transverse-electric transverse-magnetic splitting to exploit states where these two degrees of freedom are combined. To this end we develop a model based on a spin-orbit Poincaré hypersphere. Then we consider the example of semiconductor polariton systems and demonstrate full ultrafast Stark control of spin-orbit states. Moreover, by controlling states on three different spin-orbit spheres and switching from one sphere to another we demonstrate the control of different logic bits within one single physical system.

A hydrodynamic treatment of the tilted cold dark matter cosmological scenario

NASA Technical Reports Server (NTRS)

Cen, Renyue; Ostriker, Jeremiah P.

1993-01-01

A standard hydrodynamic code coupled with a particle-mesh code is used to compute the evolution of a tilted cold dark matter (TCDM) model containing both baryonic matter and dark matter. Six baryonic species are followed, with allowance for both collisional and radiative ionization in every cell. The mean final Zel'dovich-Sunyaev y parameter is estimated to be (5.4 +/- 2.7) x 10 exp -7, below currently attainable observations, with an rms fluctuation of about (6.0 +/- 3.0) x 10 exp -7 on arcmin scales. The rate of galaxy formation peaks at a relatively late epoch (z is about 0.5). In the case of mass function, the smallest objects are stabilized against collapse by thermal energy: the mass-weighted mass spectrum peaks in the vicinity of 10 exp 9.1 solar masses, with a reasonable fit to the Schechter luminosity function if the baryon mass to blue light ratio is about 4. It is shown that a bias factor of 2 required for the model to be consistent with COBE DMR signals is probably a natural outcome in the present multiple component simulations.

Electrical Tuning of Exciton-Plasmon Polariton Coupling in Monolayer MoS2 Integrated with Plasmonic Nanoantenna Lattice.

PubMed

Lee, Bumsu; Liu, Wenjing; Naylor, Carl H; Park, Joohee; Malek, Stephanie C; Berger, Jacob S; Johnson, A T Charlie; Agarwal, Ritesh

2017-07-12

Active control of light-matter interactions in semiconductors is critical for realizing next generation optoelectronic devices with real-time control of the system's optical properties and hence functionalities via external fields. The ability to dynamically manipulate optical interactions by applied fields in active materials coupled to cavities with fixed geometrical parameters opens up possibilities of controlling the lifetimes, oscillator strengths, effective mass, and relaxation properties of a coupled exciton-photon (or plasmon) system. Here, we demonstrate electrical control of exciton-plasmon coupling strengths between strong and weak coupling limits in a two-dimensional semiconductor integrated with plasmonic nanoresonators assembled in a field-effect transistor device by electrostatic doping. As a result, the energy-momentum dispersions of such an exciton-plasmon coupled system can be altered dynamically with applied electric field by modulating the excitonic properties of monolayer MoS 2 arising from many-body effects. In addition, evidence of enhanced coupling between charged excitons (trions) and plasmons was also observed upon increased carrier injection, which can be utilized for fabricating Fermionic polaritonic and magnetoplasmonic devices. The ability to dynamically control the optical properties of a coupled exciton-plasmonic system with electric fields demonstrates the versatility of the coupled system and offers a new platform for the design of optoelectronic devices with precisely tailored responses.

Dark Forces at KLOE/KLOE-2

NASA Astrophysics Data System (ADS)

Curciarello, Francesca

2014-05-01

Searches for dark matter particles in the GeV mass range and for dark forces are strongly motivated by the numerous striking astrophysical observations recently reported by many experiments. Flavor factories, like the Frascati Φ-factory DAΦNE, are particularly suited to search for the light gauge vector boson, called U boson, which is thought to mediate an unknown interaction between hypothetical dark matter particles. By using the KLOE detector, limits on U boson coupling factor ɛ2 of the order of 10-5 ÷ 10-7 have been set through the study of the ϕ Dalitz decay, the Higgsstrahlung process and Uγ events. New experiments with the upgraded KLOE detector and the increased luminosity of DAΦNE are expected to improve the already set upper limits by a factor of two or better.

High-Quality In-Plane Aligned CsPbX3 Perovskite Nanowire Lasers with Composition-Dependent Strong Exciton-Photon Coupling.

PubMed

Wang, Xiaoxia; Shoaib, Muhammad; Wang, Xiao; Zhang, Xuehong; He, Mai; Luo, Ziyu; Zheng, Weihao; Li, Honglai; Yang, Tiefeng; Zhu, Xiaoli; Ma, Libo; Pan, Anlian

2018-06-14

Cesium lead halide perovskite nanowires have emerged as promising low-dimensional semiconductor structures for integrated photonic applications. Understanding light-matter interactions in a nanowire cavity is of both fundamental and practical interest in designing low-power-consumption nanoscale light sources. In this work, high-quality in-plane aligned halide perovskite CsPbX 3 (X = Cl, Br, I) nanowires are synthesized by a vapor growth method on an annealed M-plane sapphire substrate. Large-area nanowire laser arrays have been achieved based on the as-grown aligned CsPbX 3 nanowires at room temperature with quite low pumping thresholds, very high quality factors, and a high degree of linear polarization. More importantly, it is found that exciton-polaritons are formed in the nanowires under the excitation of a pulsed laser, indicating a strong exciton-photon coupling in the optical microcavities made of cesium lead halide perovskites. The coupling strength in these CsPbX 3 nanowires is dependent on the atomic composition, where the obtained room-temperature Rabi splitting energy is ∼210 ± 13, 146 ± 9, and 103 ± 5 meV for the CsPbCl 3 , CsPbBr 3 , and CsPbI 3 nanowires, respectively. This work provides fundamental insights for the practical applications of all-inorganic perovskite CsPbX 3 nanowires in designing light-emitting devices and integrated nanophotonic systems.

Search for associated production of dark matter with a Higgs boson decaying to $$ \\mathrm{b}\\overline{\\mathrm{b}} $$ or γγ at $$ \\sqrt{s}=13 $$ TeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sirunyan, A. M.; Tumasyan, A.; Adam, W.

A search for dark matter is performed looking for events with large missing transverse momentum and a Higgs boson decaying either to a pair of bottom quarks or to a pair of photons. The data from proton-proton collisions at a center-of-mass energy of 13 TeV, collected in 2015 with the CMS detector at the LHC, correspond to an integrated luminosity of 2.3 fb –1. Results are interpreted in the context of a Z'-two-Higgs-doublet model, where the gauge symmetry of the standard model is extended by a U(1) Z' group, with a new massive Z' gauge boson, and the Higgs sectormore » is extended with four additional Higgs bosons. In this model, a high-mass resonance Z' decays into a pseudoscalar boson A and a light SM-like scalar Higgs boson, and the A decays to a pair of dark matter particles. No significant excesses are observed over the background prediction. Combining results from the two decay channels yields exclusion limits in the signal cross section in the m Z' - m A phase space. For example, the observed data exclude the Z' mass range from 600 to 1860 GeV, for Z' coupling strength g Z' = 0.8, the coupling of A with dark matter particles g χ = 1, the ratio of the vacuum expectation values tan β = 1, and m A = 300 GeV. Furthermore, the results of this analysis are valid for any dark matter particle mass below 100 GeV.« less

Search for associated production of dark matter with a Higgs boson decaying to $$ \\mathrm{b}\\overline{\\mathrm{b}} $$ or γγ at $$ \\sqrt{s}=13 $$ TeV

DOE PAGES

Sirunyan, A. M.; Tumasyan, A.; Adam, W.; ...

2017-10-25

A search for dark matter is performed looking for events with large missing transverse momentum and a Higgs boson decaying either to a pair of bottom quarks or to a pair of photons. The data from proton-proton collisions at a center-of-mass energy of 13 TeV, collected in 2015 with the CMS detector at the LHC, correspond to an integrated luminosity of 2.3 fb –1. Results are interpreted in the context of a Z'-two-Higgs-doublet model, where the gauge symmetry of the standard model is extended by a U(1) Z' group, with a new massive Z' gauge boson, and the Higgs sectormore » is extended with four additional Higgs bosons. In this model, a high-mass resonance Z' decays into a pseudoscalar boson A and a light SM-like scalar Higgs boson, and the A decays to a pair of dark matter particles. No significant excesses are observed over the background prediction. Combining results from the two decay channels yields exclusion limits in the signal cross section in the m Z' - m A phase space. For example, the observed data exclude the Z' mass range from 600 to 1860 GeV, for Z' coupling strength g Z' = 0.8, the coupling of A with dark matter particles g χ = 1, the ratio of the vacuum expectation values tan β = 1, and m A = 300 GeV. Furthermore, the results of this analysis are valid for any dark matter particle mass below 100 GeV.« less

Tunable multipole resonances in plasmonic crystals made by four-beam holographic lithography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Y.; Li, X.; Zhang, X.

2016-02-01

Plasmonic nanostructures confine light to sub-wavelength scales, resulting in drastically enhanced light-matter interactions. Recent interest has focused on controlled symmetry breaking to create higher-order multipole plasmonic modes that store electromagnetic energy more efficiently than dipole modes. Here we demonstrate that four-beam holographic lithography enables fabrication of large-area plasmonic crystals with near-field coupled plasmons as well as deliberately broken symmetry to sustain multipole modes and Fano-resonances. Compared with the spectrally broad dipole modes we demonstrate an order of magnitude improved Q-factors (Q = 21) when the quadrupole mode is activated. We further demonstrate continuous tuning of the Fano-resonances using the polarization state ofmore » the incident light beam. The demonstrated technique opens possibilities to extend the rich physics of multipole plasmonic modes to wafer-scale applications that demand low-cost and high-throughput.« less

Deterministic control of radiative processes by shaping the mode field

NASA Astrophysics Data System (ADS)

Pellegrino, D.; Pagliano, F.; Genco, A.; Petruzzella, M.; van Otten, F. W.; Fiore, A.

2018-04-01

Quantum dots (QDs) interacting with confined light fields in photonic crystal cavities represent a scalable light source for the generation of single photons and laser radiation in the solid-state platform. The complete control of light-matter interaction in these sources is needed to fully exploit their potential, but it has been challenging due to the small length scales involved. In this work, we experimentally demonstrate the control of the radiative interaction between InAs QDs and one mode of three coupled nanocavities. By non-locally moulding the mode field experienced by the QDs inside one of the cavities, we are able to deterministically tune, and even inhibit, the spontaneous emission into the mode. The presented method will enable the real-time switching of Rabi oscillations, the shaping of the temporal waveform of single photons, and the implementation of unexplored nanolaser modulation schemes.

One-shot spectrometer for several elements using an integrated conical crystal analyzer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morishita, Kohei; Nakajima, Kazuo; Hayashi, Kouichi

Time-resolved x-ray spectrometry using an ultrastrong x-ray source such as an x-ray free electron laser is one of the new trends in the field of x-ray physics. To achieve such time-resolved measurement, the development of an one-shot spectrometer with a wide wavelength range, high efficiency, and good energy resolution is an essential prerequisite. Here we developed an integrated conical Ge crystal analyzer consisting of several conical rings, which were connected using spline surfaces to form a single body using our previously developed hot deformation technique, which can form a Si or Ge wafer into an arbitrary and accurate shape. Wemore » simultaneously focused several characteristic lines from an alloy sample onto different positions on a small x-ray charge-coupled device with very high image brightness (gain relative to planar analyzer: 100) and a good spatial resolution of 9-13 eV. The small radius of curvature of the crystal (28-50 mm) enabled us to realize a very short sample-detector distance of 214.4 mm. The present result shows the possibility of realizing a new focusing x-ray crystal spectrograph that can control the focal position as desired.« less

Evolution of the entanglement of the N00N-type of states in a coupled two cavity system via an adiabatic approximation

NASA Astrophysics Data System (ADS)

Chakrabarti, R.; Sreekumari, G.; Yogesh, V.

2018-06-01

We study a system of two cavities each encapsulating a qubit and an oscillator degrees of freedom. An ultrastrong interaction between the qubit and the oscillator is assumed, and the photons are allowed to hop between the cavities. A partition of the time scale between the fast-moving oscillator and the slow moving qubit allows us to set up an adiabatic approximation procedure where we employ the delocalized degrees of freedom to diagonalize the Hamiltonian. The time evolution of the N00N-type initial states now furnishes, for instance, the reduced density matrix of a bipartite system of two qubits. For a macroscopic size of the N00N component of the initial state the sudden death of the entanglement between the qubits and its continued null value are prominently manifest as the information percolates to the qubits after long intervals. For the low photon numbers of the initial states the dynamics produces almost maximally entangled two-qubit states, which by utilizing the Hilbert–Schmidt distance between the density matrices, are observed to be nearly pure generalized Bell states.

Tachyon field non-minimally coupled to massive neutrino matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmad, Safia; Myrzakulov, Nurgissa; Myrzakulov, R., E-mail: safia@ctp-jamia.res.in, E-mail: nmyrzakulov@gmail.com, E-mail: rmyrzakulov@gmail.com

2016-07-01

In this paper, we consider rolling tachyon, with steep run-away type of potentials non-minimally coupled to massive neutrino matter. The coupling dynamically builds up at late times as neutrino matter turns non-relativistic. In case of scaling and string inspired potentials, we have shown that non-minimal coupling leads to minimum in the field potential. Given a suitable choice of model parameters, it is shown to give rise to late-time acceleration with the desired equation of state.

Sequential solar photo-fenton-biological system for the treatment of winery wastewaters.

PubMed

Mosteo, R; Sarasa, J; Ormad, Maria P; Ovelleiro, J L

2008-08-27

In this study, winery wastewaters are considered for degradation using heterogeneous photo-Fenton as a preliminary step before biotreatment. The heterogeneous photo-Fenton process assisted by solar light is able to partially degrade the organic matter present in winery wastewaters. When an initial hydrogen peroxide concentration of 0.1 M is used over 24 h of treatment, a degradation yield of organic matter (measured as TOC) of around 50% is reached. The later treatment (activated sludge process) allows the elimination of 90% of the initial TOC present in pretreated winery wastewaters without producing nondesired side-effects, such as the bulking phenomenon, which is usually detected when this treatment is used alone. The final effluent contains a concentration of organic matter (measured as COD) of 128 mg O2/L. The coupled system comprising the heterogeneous photo-Fenton process and biological treatment based on activated sludge in simple stage is a real alternative for the treatment of winery wastewater.

Toward (finally!) ruling out Z and Higgs mediated dark matter models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Escudero, Miguel; Berlin, Asher; Hooper, Dan

2016-12-01

In recent years, direct detection, indirect detection, and collider experiments have placed increasingly stringent constraints on particle dark matter, exploring much of the parameter space associated with the WIMP paradigm. In this paper, we focus on the subset of WIMP models in which the dark matter annihilates in the early universe through couplings to either the Standard Model Z or the Standard Model Higgs boson. Considering fermionic, scalar, and vector dark matter candidates within a model-independent context, we find that the overwhelming majority of these dark matter candidates are already ruled out by existing experiments. In the case of Zmore » mediated dark matter, the only scenarios that are not currently excluded are those in which the dark matter is a fermion with an axial coupling and with a mass either within a few GeV of the Z resonance ( m {sub DM} ≅ m {sub Z} /2) or greater than 200 GeV, or with a vector coupling and with m {sub DM} > 6 TeV . Several Higgs mediated scenarios are currently viable if the mass of the dark matter is near the Higgs pole ( m {sub DM} ≅ m {sub H} /2). Otherwise, the only scenarios that are not excluded are those in which the dark matter is a scalar (vector) heavier than 400 GeV (1160 GeV) with a Higgs portal coupling, or a fermion with a pseudoscalar (CP violating) coupling to the Standard Model Higgs boson. With the exception of dark matter with a purely pseudoscalar coupling to the Higgs, it is anticipated that planned direct detection experiments will probe nearly the entire range of models considered in this study.« less

Toward (finally!) ruling out Z and Higgs mediated dark matter models

DOE PAGES

Escudero, Miguel; Fermi National Accelerator Lab.; Berlin, Asher; ...

2016-12-15

In recent years, direct detection, indirect detection, and collider experiments have placed increasingly stringent constraints on particle dark matter, exploring much of the parameter space associated with the WIMP paradigm. In this paper, we focus on the subset of WIMP models in which the dark matter annihilates in the early universe through couplings to either the Standard Model Z or the Standard Model Higgs boson. Considering fermionic, scalar, and vector dark matter candidates within a model-independent context, we find that the overwhelming majority of these dark matter candidates are already ruled out by existing experiments. In the case of Zmore » mediated dark matter, the only scenarios that are not currently excluded are those in which the dark matter is a fermion with an axial coupling and with a mass either within a few GeV of the Z resonance (m DM ≃ m Z/2) or greater than 200 GeV, or with a vector coupling and with m DM > 6 TeV . Several Higgs mediated scenarios are currently viable if the mass of the dark matter is near the Higgs pole (m DM ≃ m H/2). Otherwise, the only scenarios that are not excluded are those in which the dark matter is a scalar (vector) heavier than 400 GeV (1160 GeV) with a Higgs portal coupling, or a fermion with a pseudoscalar (CP violating) coupling to the Standard Model Higgs boson. Furthermore, with the exception of dark matter with a purely pseudoscalar coupling to the Higgs, it is anticipated that planned direct detection experiments will probe nearly the entire range of models considered in this study.« less

Toward (finally!) ruling out Z and Higgs mediated dark matter models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Escudero, Miguel; Fermi National Accelerator Lab.; Berlin, Asher

In recent years, direct detection, indirect detection, and collider experiments have placed increasingly stringent constraints on particle dark matter, exploring much of the parameter space associated with the WIMP paradigm. In this paper, we focus on the subset of WIMP models in which the dark matter annihilates in the early universe through couplings to either the Standard Model Z or the Standard Model Higgs boson. Considering fermionic, scalar, and vector dark matter candidates within a model-independent context, we find that the overwhelming majority of these dark matter candidates are already ruled out by existing experiments. In the case of Zmore » mediated dark matter, the only scenarios that are not currently excluded are those in which the dark matter is a fermion with an axial coupling and with a mass either within a few GeV of the Z resonance (m DM ≃ m Z/2) or greater than 200 GeV, or with a vector coupling and with m DM > 6 TeV . Several Higgs mediated scenarios are currently viable if the mass of the dark matter is near the Higgs pole (m DM ≃ m H/2). Otherwise, the only scenarios that are not excluded are those in which the dark matter is a scalar (vector) heavier than 400 GeV (1160 GeV) with a Higgs portal coupling, or a fermion with a pseudoscalar (CP violating) coupling to the Standard Model Higgs boson. Furthermore, with the exception of dark matter with a purely pseudoscalar coupling to the Higgs, it is anticipated that planned direct detection experiments will probe nearly the entire range of models considered in this study.« less

On coupling NEC-violating matter to gravity

DOE PAGES

Chatterjee, Saugata; Parikh, Maulik; van der Schaar, Jan Pieter

2015-03-16

We show that effective theories of matter that classically violate the null energy condition cannot be minimally coupled to Einstein gravity without being inconsistent with both string theory and black hole thermodynamics. We argue however that they could still be either non-minimally coupled or coupled to higher-curvature theories of gravity.

What is general relativity?

NASA Astrophysics Data System (ADS)

Coley, Alan A.; Wiltshire, David L.

2017-05-01

General relativity is a set of physical and geometric principles, which lead to a set of (Einstein) field equations that determine the gravitational field and to the geodesic equations that describe light propagation and the motion of particles on the background. But open questions remain, including: what is the scale on which matter and geometry are dynamically coupled in the Einstein equations? Are the field equations valid on small and large scales? What is the largest scale on which matter can be coarse grained while following a geodesic of a solution to Einstein’s equations? We address these questions. If the field equations are causal evolution equations, whose average on cosmological scales is not an exact solution of the Einstein equations, then some simplifying physical principle is required to explain the statistical homogeneity of the late epoch Universe. Such a principle may have its origin in the dynamical coupling between matter and geometry at the quantum level in the early Universe. This possibility is hinted at by diverse approaches to quantum gravity which find a dynamical reduction to two effective dimensions at high energies on one hand, and by cosmological observations which are beginning to strongly restrict the class of viable inflationary phenomenologies on the other. We suggest that the foundational principles of general relativity will play a central role in reformulating the theory of spacetime structure to meet the challenges of cosmology in the 21st century.

Characterising dark matter searches at colliders and direct detection experiments: Vector mediators

DOE PAGES

Buchmueller, Oliver; Dolan, Matthew J.; Malik, Sarah A.; ...

2015-01-09

We introduce a Minimal Simplified Dark Matter (MSDM) framework to quantitatively characterise dark matter (DM) searches at the LHC. We study two MSDM models where the DM is a Dirac fermion which interacts with a vector and axial-vector mediator. The models are characterised by four parameters: m DM, M med , g DM and g q, the DM and mediator masses, and the mediator couplings to DM and quarks respectively. The MSDM models accurately capture the full event kinematics, and the dependence on all masses and couplings can be systematically studied. The interpretation of mono-jet searches in this framework canmore » be used to establish an equal-footing comparison with direct detection experiments. For theories with a vector mediator, LHC mono-jet searches possess better sensitivity than direct detection searches for light DM masses (≲5 GeV). For axial-vector mediators, LHC and direct detection searches generally probe orthogonal directions in the parameter space. We explore the projected limits of these searches from the ultimate reach of the LHC and multi-ton xenon direct detection experiments, and find that the complementarity of the searches remains. In conclusion, we provide a comparison of limits in the MSDM and effective field theory (EFT) frameworks to highlight the deficiencies of the EFT framework, particularly when exploring the complementarity of mono-jet and direct detection searches.« less

Nested plasmonic resonances: extraordinary enhancement of linear and nonlinear interactions.

PubMed

de Ceglia, Domenico; Vincenti, Maria Antonietta; Akozbek, Neset; Bloemer, Mark J; Scalora, Michael

2017-02-20

Plasmonic resonators can provide large local electric fields when the gap between metal components is filled with an ordinary dielectric. We consider a new concept consisting of a hybrid nanoantenna obtained by introducing a resonant, plasmonic nanoparticle strategically placed inside the gap of an aptly sized metallic antenna. The system exhibits two nested, nearly overlapping plasmonic resonances whose signature is a large field enhancement at the surface and within the bulk of the plasmonic nanoparticle that leads to unusually strong, linear and nonlinear light-matter coupling.

Impact of hydrodynamics on effective interactions in suspensions of active and passive matter.

PubMed

Krafnick, Ryan C; García, Angel E

2015-02-01

Passive particles exhibit unique properties when immersed in an active bath of self-propelling entities. In particular, an effective attraction can appear between particles that repel each other when in a passive solution. Here we numerically study the effect of hydrodynamics on an active-passive hybrid system, where we observe qualitative differences as compared to simulations with excluded volume effects alone. The results shed light on an existing discrepancy in pair lifetimes between simulation and experiment, due to the hydrodynamically enhanced stability of coupled passive particles.

Dark matter beams at LBNF

DOE PAGES

Coloma, Pilar; Dobrescu, Bogdan A.; Frugiuele, Claudia; ...

2016-04-08

High-intensity neutrino beam facilities may produce a beam of light dark matter when protons strike the target. Searches for such a dark matter beam using its scattering in a nearby detector must overcome the large neutrino background. We characterize the spatial and energy distributions of the dark matter and neutrino beams, focusing on their differences to enhance the sensitivity to dark matter. We find that a dark matter beam produced by a Zmore » $$^{'}$$ boson in the GeV mass range is both broader and more energetic than the neutrino beam. The reach for dark matter is maximized for a detector sensitive to hard neutral-current scatterings, placed at a sizable angle off the neutrino beam axis. In the case of the Long-Baseline Neutrino Facility (LBNF), a detector placed at roughly 6 degrees off axis and at a distance of about 200 m from the target would be sensitive to Z$$^{'}$$ couplings as low as 0.05. This search can proceed symbiotically with neutrino measurements. We also show that the MiniBooNE and MicroBooNE detectors, which are on Fermilab’s Booster beamline, happen to be at an optimal angle from the NuMI beam and could perform searches with existing data. As a result, this illustrates potential synergies between LBNF and the short-baseline neutrino program if the detectors are positioned appropriately.« less

Electrical pumping and tuning of exciton-polaritons in carbon nanotube microcavities

NASA Astrophysics Data System (ADS)

Graf, Arko; Held, Martin; Zakharko, Yuriy; Tropf, Laura; Gather, Malte C.; Zaumseil, Jana

2017-09-01

Exciton-polaritons are hybrid light-matter particles that form upon strong coupling of an excitonic transition to a cavity mode. As bosons, polaritons can form condensates with coherent laser-like emission. For organic materials, optically pumped condensation was achieved at room temperature but electrically pumped condensation remains elusive due to insufficient polariton densities. Here we combine the outstanding optical and electronic properties of purified, solution-processed semiconducting (6,5) single-walled carbon nanotubes (SWCNTs) in a microcavity-integrated light-emitting field-effect transistor to realize efficient electrical pumping of exciton-polaritons at room temperature with high current densities (>10 kA cm-2) and tunability in the near-infrared (1,060 nm to 1,530 nm). We demonstrate thermalization of SWCNT polaritons, exciton-polariton pumping rates ~104 times higher than in current organic polariton devices, direct control over the coupling strength (Rabi splitting) via the applied gate voltage, and a tenfold enhancement of polaritonic over excitonic emission. This powerful material-device combination paves the way to carbon-based polariton emitters and possibly lasers.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cardani, L.; Bellini, F.; Casali, N.

The development of background-free detectors is essential for experiments searching for rare events. Bolometers, that are among the most competitive devices for the study of neutrino-less double beta decay (0νDBD) and Dark Matter interactions, suffer from the absence of techniques that allow to identify the nature of the interacting particles. This limit can be overcome by coupling the bolometer to an independent device for the measurement of the light emitted by interactions, as the combined read-out of the bolometric and light signals allows to identify and reject particles different from those of interest. CUORE, the most advanced bolometric experiment formore » 0νDBD searches, could disentangle the electrons produced by 0νDBD from the dangerous background due to α particles, by measuring the (tiny) Cherenkov light emitted by electrons and not by α’s. LUCIFER, a project based on ZnSe scintillating bolometers for the study of {sup 82}Se 0νDBD, would be competitive also in the search of Dark Matter interactions if equipped with light detectors that allow to distinguish and reject the background due to electrons and γ’s. These advances require cryogenic detectors characterized by noise lower than 20 eV, large active area, wide temperature range of operation, high radio-purity and ease in fabricating hundreds of channels. The CALDER collaboration aims to develop such detectors by exploiting the superb energy resolution and natural multiplexed read-out provided by Kinetic Inductance Detectors.« less

The Saga of Light-Matter Interaction and Magneto-optical Effects Applications to Atomic Magnetometry, Laser-cooled Atoms, Atomic Clocks, Geomagnetism, and Plant Bio-magnetism

NASA Astrophysics Data System (ADS)

Corsini, Eric P.

The quest to expand the limited sensorial domain, in particular to bridge the inability to gauge magnetic fields near and far, has driven the fabrication of remedial tools. The interaction of ferromagnetic material with a magnetic field had been the only available technique to gauge that field for several millennium. The advent of electricity and associated classical phenomena captured in the four Maxwell equations, were a step forward. In the early 1900s, the model of quantum mechanics provided a two-way leap forward. One came from the newly understood interaction of light and matter, and more specifically the three-way coupling of photons, atoms' angular momenta, and magnetic field, which are the foundations of atomic magnetometry. The other came from magnetically sensitive quantum effects in a fabricated energy-ladder form of matter cooled to a temperature below that of the energy steps; these quantum effects gave rise to the superconducting quantum interference device (SQUID). Research using atomic magnetometers and SQUIDs has resulted in thousands of publications, text books, and conferences. The current status in each field is well described in Refs. [48,49,38,42] and all references therein. In this work we develop and investigate techniques and applications pertaining to atomic magnetometry. [Full text: eric.corsini gmail.com].

Monitoring adsorption of gold nanoparticles on gold nanodisk array using dark-field hyperspectral microscopy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Zhao, Fusheng; Zenasni, Oussama; Li, Jingting; Shih, Wei-Chuan

2017-02-01

Localized surface plasmon resonance (LSPR) arises from the interaction of light with noble metal nanoparticles, which induces a collective oscillation in the free electrons. The size and shape of the metallic nanostructure significantly impact LSPR frequency and strength. Nanoplasmonic sensor has become a recent research focus due to its significant signal enhancement and robust signal transduction measured by extinction spectroscopy, fluorescence, Raman scattering, and absorption spectroscopy. Dark-field microscopy, in contrast, reports the scattered photons after light-matter interactions. In this case, the nanoparticles can be understood as dipole radiators whose free electrons oscillate in concert. Coupled with spectroscopy, this platform allows the collection of plasmonically scattered spectra from gold nanoparticles. Plasmonic coupling between electron-beam lithography patterned gold nanodisks (AuND) and colloidal gold nanoparticles (AuNP) can change the plasmonic resonance of the original entities, and can be effectively studied by dark-field hyperspectral microscopy. Typically, a pronounced redshift can be observed when plasmonic coupling occurs. When these nano-entities are functionalized with interactive surface moieties, biochemistry and molecular processes can be studied. In this paper, we will present the capability of assessing the process of immobilizing streptavidin-functionalized AuNPs on an array of biotin-terminated AuNDs. By monitoring changes in the LSPR band of AuNDs, we are able to evaluate similar processes in other molecular systems. In addition, plasmon coupling induced scattering intensity variations can be measured by an electron-multiplied charge-coupled device camera for rapid in situ monitoring. This method can potentially be useful in studying dynamic biophysical and biochemical processes in situ.

A SQUID-Based RF Cavity Search for Dark Matter Axions

NASA Astrophysics Data System (ADS)

Hotz, Michael T.

The axion is a hypothetical elementary particle resulting from a solution to the "Strong-CP" problem. This serious problem in the standard model of particle physics is manifested as a 1010 discrepancy between the measured upper limit and the calculated value of the neutron's electric dipole moment. Furthermore, a light (~mueV) axion is an ideal dark matter candidate: axions would have been copiously produced during the Big Bang and would be the primary component of the dark matter in the universe. The resolution of the Strong-CP problem and the discovery of the composition of dark matter are two of the most pressing problems in physics. The observation of a light, dark-matter axion would resolve both of these problems. The Axion Dark Matter eXperiment (ADMX) is the most sensitive search for dark-matter axions. Axions in our Milky Way Galaxy may scatter off a magnetic field and convert into microwave photons. ADMX consists of a tunable high-Q RF cavity within the bore of a large, 8.5 Tesla superconducting solenoidal magnet. When the cavity's resonant frequency matches the axion's total energy, the probability of axion-to-photon conversion is enhanced. The cavity's narrow bandwidth requires ADMX to slowly scan possible axion masses. A receiver amplifies, mixes, and digitizes the power developed in the cavity from possible axion-to-photon conversions. This is the most sensitive spectral receiver of microwave radiation in the world. The resulting data is scrutinized for an axion signal above the thermal background. ADMX first operated from 1995-2005 and produced exclusion limits on the energy of dark-matter axions from 1.9 mueV to 3.3 mueV. In order to improve on these limits and continue the search for plausible dark-matter axions, the system was considerably upgraded from 2005 until 2008. In the upgrade, the key technical advance was the use of a dc Superconducting QUantum Interference Device (SQUID) as a microwave amplifier. The SQUID amplifier's noise level is near the allowed minimum from quantum mechanics, allowing ADMX to reduce its thermal noise background by up to 100x. However, SQUIDs are extremely sensitive to magnetic fields, such as those within in ADMX. Integrating a SQUID amplifier into ADMX presented a serious technical challenge. Commissioning the SQUID amplifier was a major focus of my thesis work. This work demonstrates the successful use of a SQUID amplifier in ADMX during operations from 2008-2010. Compared to other dark-matter candidates, the axion's mass and the axion's coupling strength to normal matter and radiation are rather tightly constrained. This allows for the near-definitive elimination or detection of dark-matter axions. A successful detection in ADMX would immediately lead to a determination of the axion's spectral line shape. This shape encodes the history of the Milky Way's formation and is therefore of high scientific importance. The imperfectly-constrained Milky Way dark-matter halo, however, produces remnant uncertainties of the axion signal in both its spectral line-shape and its total intensity, complicating the ADMX search. This work investigates proposed features of dark-matter halo models which enhance ADMX's sensitivity. From these models, this work presents the corresponding exclusion limits for both the local axion density and axion-to-photon coupling strength for axions with mass in the 3.36 mueV to 3.69 mueV region.

Meshless modelling of dynamic behaviour of glasses under intense shock loadings: Application to matter ejection during high velocity impacts on thin brittle targets

NASA Astrophysics Data System (ADS)

Michel, Y.; Chevalier, J.-M.; Durin, C.; Espinosa, C.; Malaise, F.; Barrau, J.-J.

2006-08-01

The purpose of this study is to present a new material model adapted to SPH modelling of dynamic behaviour of glasses under shock loadings. This model has the ability to reproduce fragmentation and densification of glasses under compression as well as brittle tensile failure. It has been implemented in Ls-Dyna software and coupled with a SPH code. By comparison with CEA-CESTA experimental data the model has been validated for fused silica and Pyrex glass for stress level up to 35GPa. For Laser MegaJoule applications, the present material model was applied to 3D high velocity impacts on thin brittle targets with good agreement with experimental data obtained using CESTA's double stage light gas gun in term of damages and matter ejection.

Flavored dark matter beyond Minimal Flavor Violation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agrawal, Prateek; Blanke, Monika; Gemmler, Katrin

We study the interplay of flavor and dark matter phenomenology for models of flavored dark matter interacting with quarks. We allow an arbitrary flavor structure in the coupling of dark matter with quarks. This coupling is assumed to be the only new source of violation of the Standard Model flavor symmetry extended by a U(3) χ associated with the dark matter. We call this ansatz Dark Minimal Flavor Violation (DMFV) and highlight its various implications, including an unbroken discrete symmetry that can stabilize the dark matter. As an illustration we study a Dirac fermionic dark matter χ which transforms asmore » triplet under U(3) χ , and is a singlet under the Standard Model. The dark matter couples to right-handed down-type quarks via a colored scalar mediator Φ with a coupling λ. We identify a number of “flavor-safe” scenarios for the structure of λ which are beyond Minimal Flavor Violation. Also, for dark matter and collider phenomenology we focus on the well-motivated case of b-flavored dark matter. Furthermore, the combined flavor and dark matter constraints on the parameter space of λ turn out to be interesting intersections of the individual ones. LHC constraints on simplified models of squarks and sbottoms can be adapted to our case, and monojet searches can be relevant if the spectrum is compressed.« less

Flavored dark matter beyond Minimal Flavor Violation

DOE PAGES

Agrawal, Prateek; Blanke, Monika; Gemmler, Katrin

2014-10-13

We study the interplay of flavor and dark matter phenomenology for models of flavored dark matter interacting with quarks. We allow an arbitrary flavor structure in the coupling of dark matter with quarks. This coupling is assumed to be the only new source of violation of the Standard Model flavor symmetry extended by a U(3) χ associated with the dark matter. We call this ansatz Dark Minimal Flavor Violation (DMFV) and highlight its various implications, including an unbroken discrete symmetry that can stabilize the dark matter. As an illustration we study a Dirac fermionic dark matter χ which transforms asmore » triplet under U(3) χ , and is a singlet under the Standard Model. The dark matter couples to right-handed down-type quarks via a colored scalar mediator Φ with a coupling λ. We identify a number of “flavor-safe” scenarios for the structure of λ which are beyond Minimal Flavor Violation. Also, for dark matter and collider phenomenology we focus on the well-motivated case of b-flavored dark matter. Furthermore, the combined flavor and dark matter constraints on the parameter space of λ turn out to be interesting intersections of the individual ones. LHC constraints on simplified models of squarks and sbottoms can be adapted to our case, and monojet searches can be relevant if the spectrum is compressed.« less

Phase-resolved two-dimensional terahertz spectroscopy - a probe of highly nonlinear light-matter interactions

NASA Astrophysics Data System (ADS)

Elsaesser, Thomas

Terahertz (THz) spectroscopy gives insight into low-frequency excitations and charge dynamics in condensed matter. So far, most experiments in a frequency range from 0.5 to 30 THz have focused on the linear THz response to determine linear absorption and disperion spectra, and/or electric conductivities. The generation of ultrashort THz transients with peak electric fields up to megavolts/cm has allowed for addressing nonlinear light-matter interactions and inducing excitations far from equilibrium. The novel method of two-dimensional THz (2D-THz) spectroscopy allows for mapping ultrafast dynamics and couplings of elementary excitations up to arbitrary nonlinear order in the electric field, both under resonant and nonresonant excitation conditions. In particular, different contributions to the overall nonlinear response are separated by dissecting it as a function of excitation and detection frequencies and for different waiting times after excitation. This talk gives an introduction in 2D-THz spectroscopy, including its recent extension to 3-pulse sequences and interaction schemes. To illustrate the potential of the method, recent results on two-phonon coherences and high-order interband excitations in the semiconductor InSb will be presented. Nonlinear THz excitation of two-phonon coherences exploits a resonance enhancement by the large electronic interband dipole of InSb and is, thus, far more efficient than linear excitation via resonant two-phonon absorption. As a second application, the nonlinear softmode response in a crystal consisting of aspirin molecules will be discussed. At moderate THz driving fields, the pronounced correlation of rotational modes of CH3 groups with collective oscillations of π-electrons drives the system into the regime of nonperturbative light-matter interaction. Nonlinear absorption around 1.1 THz leads to a blue-shifted coherent emission at 1.5 THz, revealing a dynamic breakup of the strong electron-phonon correlations.

Dynamics of interacting Dicke model in a coupled-cavity array

NASA Astrophysics Data System (ADS)

Badshah, Fazal; Qamar, Shahid; Paternostro, Mauro

2014-09-01

We consider the dynamics of an array of mutually interacting cavities, each containing an ensemble of N two-level atoms. By exploring the possibilities offered by ensembles of various dimensions and a range of atom-light and photon-hopping values, we investigate the generation of multisite entanglement, as well as the performance of excitation transfer across the array, resulting from the competition between on-site nonlinearities of the matter-light interaction and intersite photon hopping. In particular, for a three-cavity interacting system it is observed that the initial excitation in the first cavity completely transfers to the ensemble in the third cavity through the hopping of photons between the adjacent cavities. Probabilities of the transfer of excitation of the cavity modes and ensembles exhibit characteristics of fast and slow oscillations governed by coupling and hopping parameters, respectively. In the large-hopping case, by seeding an initial excitation in the cavity at the center of the array, a tripartite W state, as well as a bipartite maximally entangled state, is obtained, depending on the interaction time. Population of the ensemble in a cavity has a positive impact on the rate of excitation transfer between the ensembles and their local cavity modes. In particular, for ensembles of five to seven atoms, tripartite W states can be produced even when the hopping rate is comparable to the cavity-atom coupling rate. A similar behavior of the transfer of excitation is observed for a four-coupled-cavity system with two initial excitations.

Boosting infrared energy transfer in 3D nanoporous gold antennas.

PubMed

Garoli, D; Calandrini, E; Bozzola, A; Ortolani, M; Cattarin, S; Barison, S; Toma, A; De Angelis, F

2017-01-05

The applications of plasmonics to energy transfer from free-space radiation to molecules are currently limited to the visible region of the electromagnetic spectrum due to the intrinsic optical properties of bulk noble metals that support strong electromagnetic field confinement only close to their plasma frequency in the visible/ultraviolet range. In this work, we show that nanoporous gold can be exploited as a plasmonic material for the mid-infrared region to obtain strong electromagnetic field confinement, co-localized with target molecules into the nanopores and resonant with their vibrational frequency. The effective optical response of the nanoporous metal enables the penetration of optical fields deep into the nanopores, where molecules can be loaded thus achieving a more efficient light-matter coupling if compared to bulk gold. In order to realize plasmonic resonators made of nanoporous gold, we develop a nanofabrication method based on polymeric templates for metal deposition and we obtain antenna arrays resonating at mid-infrared wavelengths selected by design. We then coat the antennas with a thin (3 nm) silica layer acting as the target dielectric layer for optical energy transfer. We study the strength of the light-matter coupling at the vibrational absorption frequency of silica at 1240 cm -1 through the analysis of the experimental Fano lineshape that is benchmarked against identical structures made of bulk gold. The boost in the optical energy transfer from free-space mid-infrared radiation to molecular vibrations in nanoporous 3D nanoantenna arrays can open new application routes for plasmon-enhanced physical-chemical reactions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodrigues, Davi C., E-mail: davirodrigues.ufes@gmail.com

The renormalization group framework can be applied to Quantum Field Theory on curved space-time, but there is no proof whether the beta-function of the gravitational coupling indeed goes to zero in the far infrared or not. In a recent paper [1] we have shown that the amount of dark matter inside spiral galaxies may be negligible if a small running of the General Relativity coupling G is present (δG/G{sub 0}∼<10{sup −7} across a galaxy). Here we extend the proposed model to elliptical galaxies and present a detailed analysis on the modeling of NGC 4494 (an ordinary elliptical) and NGC 4374more » (a giant elliptical). In order to compare our results to a well known alternative model to the standard dark matter picture, we also evaluate NGC 4374 with MOND. In this galaxy MOND leads to a significative discrepancy with the observed velocity dispersion curve and has a significative tendency towards tangential anisotropy. On the other hand, the approach based on the renormalization group and general relativity (RGGR) could be applied with good results to these elliptical galaxies and is compatible with lower mass-to-light ratios (of about the Kroupa IMF type)« less

In pursuit of photo-induced magnetic and chiral microscopy

NASA Astrophysics Data System (ADS)

Zeng, Jinwei; Kamandi, Mohammad; Darvishzadeh-Varcheie, Mahsa; Albooyeh, Mohammad; Veysi, Mehdi; Guclu, Caner; Hanifeh, Mina; Rajaei, Mohsen; Potma, Eric O.; Wickramasinghe, H. Kumar; Capolino, Filippo

2018-06-01

Light-matter interactions enable the perception of specimen properties such as its shape and dimensions by measuring the subtle differences carried by an illuminating beam after interacting with the sample. However, major obstacles arise when the relevant properties of the specimen are weakly coupled to the incident beam, for example when measuring optical magnetism and chirality. To address this challenge we propose the idea of detecting such weakly-coupled properties of matter through the photo-induced force, aiming at developing photo-induced magnetic or chiral force microscopy. Here we review our pursuit consisting of the following steps: (1) Development of a theoretical blueprint of a magnetic nanoprobe to detect a magnetic dipole oscillating at an optical frequency when illuminated by an azimuthally polarized beam via the photo-induced magnetic force; (2) Conducting an experimental study using an azimuthally polarized beam to probe the near fields and axial magnetism of a Si disk magnetic nanoprobe, based on photo-induced force microscopy; (3) Extending the concept of force microscopy to probe chirality at the nanoscale, enabling enantiomeric detection of chiral molecules. Finally, we discuss difficulties and how they could be overcome, as well as our plans for future work. Invited Paper

Sigma omega meson coupling and properties of nuclei and nuclear matter

NASA Astrophysics Data System (ADS)

Haidari, Maryam M.; Sharma, Madan M.

2008-05-01

We have constructed a Lagrangian model with a coupling of σ and ω mesons in the relativistic mean-field theory. Properties of finite nuclei and nuclear matter are explored with the new Lagrangian model SIG-OM. The study shows that an excellent description of binding energies and charge radii of nuclei over a large range of isospin is achieved with SIG-OM. With an incompressibility of nuclear matter K=265 MeV, it is also able to describe the breathing-mode isoscalar giant monopole resonance energies appropriately. It is shown that the high-density behaviour of the equation of state of nuclear and neutron matter with the σ-ω coupling is much softer than that of the non-linear scalar coupling model.

Ultrastrong Graphene-Based Fibers with Increased Elongation.

PubMed

Li, Mochen; Zhang, Xiaohong; Wang, Xiang; Ru, Yue; Qiao, Jinliang

2016-10-12

A new method to prepare graphene-based fibers with ultrahigh tensile strength, conductivity, and increased elongation is reported. It includes wet-spinning the mixture of GO aqueous dispersion with phenolic resin solution in a newly developed coagulation bath, followed by annealing. The introduced phenolic carbon increased densification of graphene fibers through reducing defects and increased interfacial interaction among graphene sheets by forming new C-C bonds, thus resulting in the increasing of stiffness, toughness, and conductivity simultaneously.

Recent progress in the research of inorganic fullerene-like nanoparticles and inorganic nanotubes.

PubMed

Tenne, Reshef; Redlich, Meir

2010-05-01

Nanoparticles of inorganic compounds with layered (2D) structures, like graphite and MoS(2), were shown to be unstable in the planar from and fold on themselves forming seamless hollow structures like multiwall nanotubes and fullerene-like nanoparticles. The present concise tutorial review reports on the salient developments in this field over the last several years. Numerous applications for such nanophases have been proposed, like solid lubricants, ultra-strong nanocomposites, catalysts, etc.

Exponentially Enhanced Light-Matter Interaction, Cooperativities, and Steady-State Entanglement Using Parametric Amplification

NASA Astrophysics Data System (ADS)

Qin, Wei; Miranowicz, Adam; Li, Peng-Bo; Lü, Xin-You; You, J. Q.; Nori, Franco

2018-03-01

We propose an experimentally feasible method for enhancing the atom-field coupling as well as the ratio between this coupling and dissipation (i.e., cooperativity) in an optical cavity. It exploits optical parametric amplification to exponentially enhance the atom-cavity interaction and, hence, the cooperativity of the system, with the squeezing-induced noise being completely eliminated. Consequently, the atom-cavity system can be driven from the weak-coupling regime to the strong-coupling regime for modest squeezing parameters, and even can achieve an effective cooperativity much larger than 100. Based on this, we further demonstrate the generation of steady-state nearly maximal quantum entanglement. The resulting entanglement infidelity (which quantifies the deviation of the actual state from a maximally entangled state) is exponentially smaller than the lower bound on the infidelities obtained in other dissipative entanglement preparations without applying squeezing. In principle, we can make an arbitrarily small infidelity. Our generic method for enhancing atom-cavity interaction and cooperativities can be implemented in a wide range of physical systems, and it can provide diverse applications for quantum information processing.

Bipolarons in one-dimensional extended Peierls-Hubbard models

NASA Astrophysics Data System (ADS)

Sous, John; Chakraborty, Monodeep; Krems, Roman; Berciu, Mona

2017-04-01

We study two particles in an infinite chain and coupled to phonons by interactions that modulate their hopping as described by the Peierls/Su-Schrieffer-Heeger (SSH) model. In the case of hard-core bare particles, we show that exchange of phonons generates effective nearest-neighbor repulsion between particles and also gives rise to interactions that move the pair as a whole. The two-polaron phase diagram exhibits two sharp transitions, leading to light dimers at strong coupling and the flattening of the dimer dispersion at some critical values of the parameters. This dimer (quasi)self-trapping occurs at coupling strengths where single polarons are mobile. On the other hand, in the case of soft-core particles/ spinfull fermions, we show that phonon-mediated interactions are attractive and result in strongly bound and mobile bipolarons in a wide region of parameter space. This illustrates that, depending on the strength of the phonon-mediated interactions and statistics of bare particles, the coupling to phonons may completely suppress or strongly enhance quantum transport of correlated particles. This work was supported by NSERC of Canada and the Stewart Blusson Quantum Matter Institute.

Recognising Axionic Dark Matter by Compton and de-Broglie Scale Modulation of Pulsar Timing

NASA Astrophysics Data System (ADS)

De Martino, Ivan; Broadhurst, Tom; Tye, S.-H. Henry; Chiueh, Tzihong; Schive, Hsi-Yu; Lazkoz, Ruth

2017-11-01

Light Axionic Dark Matter, motivated by string theory, is increasingly favored for the "no-WIMP era". Galaxy formation is suppressed below a Jeans scale, of ≃ 10^8 M_⊙ by setting the axion mass to, m_B ˜ 10^{-22}eV, and the large dark cores of dwarf galaxies are explained as solitons on the de-Broglie scale. This is persuasive, but detection of the inherent scalar field oscillation at the Compton frequency, ω_B= (2.5 months)^{-1}(m_B/10^{-22}eV), would be definitive. By evolving the coupled Schrödinger-Poisson equation for a Bose-Einstein condensate, we predict the dark matter is fully modulated by de-Broglie interference, with a dense soliton core of size ≃ 150pc, at the Galactic center. The oscillating field pressure induces General Relativistic time dilation in proportion to the local dark matter density and pulsars within this dense core have detectably large timing residuals, of ≃ 400nsec/(m_B/10^{-22}eV). This is encouraging as many new pulsars should be discovered near the Galactic center with planned radio surveys. More generally, over the whole Galaxy, differences in dark matter density between pairs of pulsars imprints a pairwise Galactocentric signature that can be distinguished from an isotropic gravitational wave background.

Leptogenesis as an origin of hot dark matter and baryon asymmetry in the E6 inspired SUSY models

NASA Astrophysics Data System (ADS)

Nevzorov, R.

2018-04-01

We explore leptogenesis within the E6 inspired U (1) extension of the MSSM in which exact custodial symmetry forbids tree-level flavour-changing transitions and the most dangerous baryon and lepton number violating operators. This supersymmetric (SUSY) model involves extra exotic matter beyond the MSSM. In the simplest phenomenologically viable scenarios the lightest exotic fermions are neutral and stable. These states should be substantially lighter than 1eV forming hot dark matter in the Universe. The low-energy effective Lagrangian of the SUSY model under consideration possesses an approximate global U(1)E symmetry associated with the exotic states. The U(1)E symmetry is explicitly broken because of the interactions between the right-handed neutrino superfields and exotic matter supermultiplets. As a consequence the decays of the lightest right-handed neutrino/sneutrino give rise to both U(1)E and U(1) B - L asymmetries. When all right-handed neutrino/sneutrino are relatively light ∼106-107GeV the appropriate amount of the baryon asymmetry can be induced via these decays if the Yukawa couplings of the lightest right-handed neutrino superfields to the exotic matter supermultiplets vary between ∼10-4-10-3.

Searching for light dark matter with the SLAC millicharge experiment.

PubMed

Diamond, M; Schuster, P

2013-11-27

New sub-GeV gauge forces ("dark photons") that kinetically mix with the photon provide a promising scenario for MeV-GeV dark matter and are the subject of a program of searches at fixed-target and collider facilities around the world. In such models, dark photons produced in collisions may decay invisibly into dark-matter states, thereby evading current searches. We reexamine results of the SLAC mQ electron beam dump experiment designed to search for millicharged particles and find that it was strongly sensitive to any secondary beam of dark matter produced by electron-nucleus collisions in the target. The constraints are competitive for dark photon masses in the ~1-30 MeV range, covering part of the parameter space that can reconcile the apparent (g-2)(μ) anomaly. Simple adjustments to the original SLAC search for millicharges may extend sensitivity to cover a sizable portion of the remaining (g-2)(μ) anomaly-motivated region. The mQ sensitivity is therefore complementary to ongoing searches for visible decays of dark photons. Compared to existing direct-detection searches, mQ sensitivity to electron-dark-matter scattering cross sections is more than an order of magnitude better for a significant range of masses and couplings in simple models.

Coupling between graphene and intersubband collective excitations in quantum wells

NASA Astrophysics Data System (ADS)

Gonzalez de la Cruz, G.

2017-08-01

Recently, strong light-matter coupling between the electromagnetic modes in plasmonic metasurfaces with quantum-engineering electronic intersubband transitions in quantum wells has been demonstrated experimentally (Benz et al., [14], Lee et al., [15]). These novel materials combining different two-dimensional electronic systems offer new opportunities for tunable optical devices and fundamental studies of collective excitations driven by interlayer Coulomb interactions. In this work, our aim is to study the plasmon spectra of a hybrid structure consisting of conventional two-dimensional electron gas (2DEG) in a semiconductor quantum well and a graphene sheet with an interlayer separation of a. This electronic bilayer structure is immersed in a nonhomgeneous dielectric background of the system. We use a simple model in which the graphene surface plasmons and both; the intrasubband and intersubband collective electron excitations in the quantum well are coupled via screened Coulomb interaction. Here we calculate the dispersion of these relativistic/nonrelativistic new plasmon modes taking into account the thickness of the quantum well providing analytical expressions in the long-wavelength limit.

Tunable room-temperature spin-selective optical Stark effect in solution-processed layered halide perovskites

PubMed Central

Giovanni, David; Chong, Wee Kiang; Dewi, Herlina Arianita; Thirumal, Krishnamoorthy; Neogi, Ishita; Ramesh, Ramamoorthy; Mhaisalkar, Subodh; Mathews, Nripan; Sum, Tze Chien

2016-01-01

Ultrafast spin manipulation for opto–spin logic applications requires material systems that have strong spin-selective light-matter interaction. Conventional inorganic semiconductor nanostructures [for example, epitaxial II to VI quantum dots and III to V multiple quantum wells (MQWs)] are considered forerunners but encounter challenges such as lattice matching and cryogenic cooling requirements. Two-dimensional halide perovskite semiconductors, combining intrinsic tunable MQW structures and large oscillator strengths with facile solution processability, can offer breakthroughs in this area. We demonstrate novel room-temperature, strong ultrafast spin-selective optical Stark effect in solution-processed (C6H4FC2H4NH3)2PbI4 perovskite thin films. Exciton spin states are selectively tuned by ~6.3 meV using circularly polarized optical pulses without any external photonic cavity (that is, corresponding to a Rabi energy of ~55 meV and equivalent to applying a 70 T magnetic field), which is much larger than any conventional system. The facile halide and organic replacement in these perovskites affords control of the dielectric confinement and thus presents a straightforward strategy for tuning light-matter coupling strength. PMID:27386583

Asymptotic safety of gravity with matter

NASA Astrophysics Data System (ADS)

Christiansen, Nicolai; Litim, Daniel F.; Pawlowski, Jan M.; Reichert, Manuel

2018-05-01

We study the asymptotic safety conjecture for quantum gravity in the presence of matter fields. A general line of reasoning is put forward explaining why gravitons dominate the high-energy behavior, largely independently of the matter fields as long as these remain sufficiently weakly coupled. Our considerations are put to work for gravity coupled to Yang-Mills theories with the help of the functional renormalization group. In an expansion about flat backgrounds, explicit results for beta functions, fixed points, universal exponents, and scaling solutions are given in systematic approximations exploiting running propagators, vertices, and background couplings. Invariably, we find that the gauge coupling becomes asymptotically free while the gravitational sector becomes asymptotically safe. The dependence on matter field multiplicities is weak. We also explain how the scheme dependence, which is more pronounced, can be handled without changing the physics. Our findings offer a new interpretation of many earlier results, which is explained in detail. The results generalize to theories with minimally coupled scalar and fermionic matter. Some implications for the ultraviolet closure of the Standard Model or its extensions are given.

A New Computational Tool for Understanding Light-Matter Interactions

DTIC Science & Technology

2016-02-11

SECURITY CLASSIFICATION OF: Plasmonic resonance of a metallic nanostructure results from coherent motion of its conduction electrons driven by...Box 12211 Research Triangle Park, NC 27709-2211 Plasmonics , light-matter interaction, time-dependent density functional theory, modeling and...reviewed journals: Final Report: A New Computational Tool For Understanding Light-Matter Interactions Report Title Plasmonic resonance of a metallic

Aramid nanofiber-functionalized graphene nanosheets for polymer reinforcement

NASA Astrophysics Data System (ADS)

Fan, Jinchen; Shi, Zixing; Zhang, Lu; Wang, Jialiang; Yin, Jie

2012-10-01

Aramid macroscale fibers, also called Kevlar fibers, exhibit extremely high mechanical performance. Previous studies have demonstrated that bulk aramid macroscale fibers can be effectively split into aramid nanofibers (ANFs) by dissolution in dimethylsulfoxide (DMSO) in the presence of potassium hydroxide (KOH). In this paper, we first introduced the ANFs into the structure of graphene nanosheets through non-covalent functionalization through π-π stacking interactions. Aramid nanofiber-functionalized graphene sheets (ANFGS) were successfully obtained by adding the graphene oxide (GO)/DMSO dispersion into the ANFs/DMSO solution followed by reduction with hydrazine hydrate. The ANFGS, with ANFs absorbed on the surface of the graphene nanosheets, can be easily exfoliated and dispersed in N-methyl-2-pyrrolidone (NMP). Through a combination of these two ultra-strong materials, ANFs and graphene nanosheets (GS), the resultant ANFGS can act as novel nanofillers for polymer reinforcement. We used the ANFGS as an additive for reinforcing the mechanical properties of poly(methyl methacrylate) (PMMA). With a loading of 0.7 wt% of the ANFGS, the tensile strength and Young's modulus of the ANFGS/PMMA composite film approached 63.2 MPa and 3.42 GPa, which are increases of ~84.5% and ~70.6%, respectively. The thermal stabilities of ANFGS/PMMA composite films were improved by the addition of ANFGS. Additionally, the transparencies of the ANFGS/PMMA composite films have a degree of UV-shielding due to the ultraviolet light absorption of the ANFs in the ANFGS.Aramid macroscale fibers, also called Kevlar fibers, exhibit extremely high mechanical performance. Previous studies have demonstrated that bulk aramid macroscale fibers can be effectively split into aramid nanofibers (ANFs) by dissolution in dimethylsulfoxide (DMSO) in the presence of potassium hydroxide (KOH). In this paper, we first introduced the ANFs into the structure of graphene nanosheets through non-covalent functionalization through π-π stacking interactions. Aramid nanofiber-functionalized graphene sheets (ANFGS) were successfully obtained by adding the graphene oxide (GO)/DMSO dispersion into the ANFs/DMSO solution followed by reduction with hydrazine hydrate. The ANFGS, with ANFs absorbed on the surface of the graphene nanosheets, can be easily exfoliated and dispersed in N-methyl-2-pyrrolidone (NMP). Through a combination of these two ultra-strong materials, ANFs and graphene nanosheets (GS), the resultant ANFGS can act as novel nanofillers for polymer reinforcement. We used the ANFGS as an additive for reinforcing the mechanical properties of poly(methyl methacrylate) (PMMA). With a loading of 0.7 wt% of the ANFGS, the tensile strength and Young's modulus of the ANFGS/PMMA composite film approached 63.2 MPa and 3.42 GPa, which are increases of ~84.5% and ~70.6%, respectively. The thermal stabilities of ANFGS/PMMA composite films were improved by the addition of ANFGS. Additionally, the transparencies of the ANFGS/PMMA composite films have a degree of UV-shielding due to the ultraviolet light absorption of the ANFs in the ANFGS. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr31907a

Curved non-relativistic spacetimes, Newtonian gravitation and massive matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geracie, Michael, E-mail: mgeracie@uchicago.edu; Prabhu, Kartik, E-mail: kartikp@uchicago.edu; Roberts, Matthew M., E-mail: matthewroberts@uchicago.edu

2015-10-15

There is significant recent work on coupling matter to Newton-Cartan spacetimes with the aim of investigating certain condensed matter phenomena. To this end, one needs to have a completely general spacetime consistent with local non-relativistic symmetries which supports massive matter fields. In particular, one cannot impose a priori restrictions on the geometric data if one wants to analyze matter response to a perturbed geometry. In this paper, we construct such a Bargmann spacetime in complete generality without any prior restrictions on the fields specifying the geometry. The resulting spacetime structure includes the familiar Newton-Cartan structure with an additional gauge fieldmore » which couples to mass. We illustrate the matter coupling with a few examples. The general spacetime we construct also includes as a special case the covariant description of Newtonian gravity, which has been thoroughly investigated in previous works. We also show how our Bargmann spacetimes arise from a suitable non-relativistic limit of Lorentzian spacetimes. In a companion paper [M. Geracie et al., e-print http://arxiv.org/abs/1503.02680 ], we use this Bargmann spacetime structure to investigate the details of matter couplings, including the Noether-Ward identities, and transport phenomena and thermodynamics of non-relativistic fluids.« less

Perspective: Photonic flatbands

NASA Astrophysics Data System (ADS)

Leykam, Daniel; Flach, Sergej

2018-07-01

Flatbands are receiving increasing theoretical and experimental attention in the field of photonics, in particular in the field of photonic lattices. Flatband photonic lattices consist of arrays of coupled waveguides or resonators where the peculiar lattice geometry results in at least one completely flat or dispersionless band in its photonic band structure. Although bearing a strong resemblance to structural slow light, this independent research direction is instead inspired by analogies with "frustrated" condensed matter systems. In this Perspective, we critically analyze the research carried out to date, discuss how this exotic physics may lead to novel photonic device applications, and chart promising future directions in theory and experiment.

The photo-philic QCD axion

DOE PAGES

Farina, Marco; Pappadopulo, Duccio; Rompineve, Fabrizio; ...

2017-01-23

Here, we propose a framework in which the QCD axion has an exponentially large coupling to photons, relying on the “clockwork” mechanism. We discuss the impact of present and future axion experiments on the parameter space of the model. In addition to the axion, the model predicts a large number of pseudoscalars which can be light and observable at the LHC. In the most favorable scenario, axion Dark Matter will give a signal in multiple axion detection experiments and the pseudo-scalars will be discovered at the LHC, allowing us to determine most of the parameters of the model.

Interdependence of different symmetry energy elements

NASA Astrophysics Data System (ADS)

Mondal, C.; Agrawal, B. K.; De, J. N.; Samaddar, S. K.; Centelles, M.; Viñas, X.

2017-08-01

Relations between the nuclear symmetry energy coefficient and its density derivatives are derived. The relations hold for a class of interactions with quadratic momentum dependence and a power-law density dependence. The structural connection between the different symmetry energy elements as obtained seems to be followed by almost all reasonable nuclear energy density functionals, both relativistic and nonrelativistic, suggesting a universality in the correlation structure. This, coupled with known values of some well-accepted constants related to nuclear matter, helps in constraining values of different density derivatives of the nuclear symmetry energy, shedding light on the isovector part of the nuclear interaction.

Exploring the nonlinear regime of light-matter interaction using electronic spins in diamond

NASA Astrophysics Data System (ADS)

Alfasi, Nir; Masis, Sergei; Winik, Roni; Farfurnik, Demitry; Shtempluck, Oleg; Bar-Gill, Nir; Buks, Eyal

2018-06-01

The coupling between defects in diamond and a superconducting microwave resonator is studied in the nonlinear regime. Both negatively charged nitrogen-vacancy and P1 defects are explored. The measured cavity mode response exhibits strong nonlinearity near a spin resonance. Data is compared with theoretical predictions and a good agreement is obtained in a wide range of externally controlled parameters. The nonlinear effect under study in the current paper is expected to play a role in any cavity-based magnetic resonance imaging technique and to impose a fundamental limit upon its sensitivity.

Dark Matter Decays from Nonminimal Coupling to Gravity.

PubMed

Catà, Oscar; Ibarra, Alejandro; Ingenhütt, Sebastian

2016-07-08

We consider the standard model extended with a dark matter particle in curved spacetime, motivated by the fact that the only current evidence for dark matter is through its gravitational interactions, and we investigate the impact on the dark matter stability of terms in the Lagrangian linear in the dark matter field and proportional to the Ricci scalar. We show that this "gravity portal" induces decay even if the dark matter particle only has gravitational interactions, and that the decay branching ratios into standard model particles only depend on one free parameter: the dark matter mass. We study in detail the case of a singlet scalar as a dark matter candidate, which is assumed to be absolutely stable in flat spacetime due to a discrete Z_{2} symmetry, but which may decay in curved spacetimes due to a Z_{2}-breaking nonminimal coupling to gravity. We calculate the dark matter decay widths and we set conservative limits on the nonminimal coupling parameter from experiments. The limits are very stringent and suggest that there must exist an additional mechanism protecting the singlet scalar from decaying via this gravity portal.

Dynamics of a spherically symmetric inhomogeneous coupled dark energy model with coupling term proportional to non relatvistic matter

NASA Astrophysics Data System (ADS)

Izquierdo, Germán; Blanquet-Jaramillo, Roberto C.; Sussman, Roberto A.

2018-01-01

The quasi-local scalar variables approach is applied to a spherically symmetric inhomogeneous Lemaître-Tolman-Bondi metric containing a mixture of non-relativistic cold dark matter and coupled dark energy with constant equation of state. The quasi-local coupling term considered is proportional to the quasi-local cold dark matter energy density and a quasi-local Hubble factor-like scalar via a coupling constant α . The autonomous numerical system obtained from the evolution equations is classified for different choices of the free parameters: the adiabatic constant of the dark energy w and α . The presence of a past attractor in a non-physical region of the energy densities phase-space of the system makes the coupling term non physical when the energy flows from the matter to the dark energy in order to avoid negative values of the dark energy density in the past. On the other hand, if the energy flux goes from dark energy to dark matter, the past attractor lies in a physical region. The system is also numerically solved for some interesting initial profiles leading to different configurations: an ever expanding mixture, a scenario where the dark energy is completely consumed by the non-relativistic matter by means of the coupling term, a scenario where the dark energy disappears in the inner layers while the outer layers expand as a mixture of both sources, and, finally, a structure formation toy model scenario, where the inner shells containing the mixture collapse while the outer shells expand.

Leptophilic dark matter in gauged U(1)_{L{_e}-L_{μ }} model in light of DAMPE cosmic ray {e{^+}} + {e{^-}} excess

NASA Astrophysics Data System (ADS)

Duan, Guang Hua; He, Xiao-Gang; Wu, Lei; Yang, Jin Min

2018-04-01

Motivated by the very recent cosmic-ray electron+positron excess observed by DAMPE collaboration, we investigate a Dirac fermion dark matter (DM) in the gauged {{L_e} - {L_μ }} model. DM interacts with the electron and muon via the U(1)_{e-μ } gauge boson Z^' . The model can explain the DAMPE data well. Although a non-zero DM-nucleon cross section is only generated at one loop level and there is a partial cancellation between Z^' }ee and Z^' }μ μ couplings, we find that a large portion of Z' mass is ruled out from direct DM detection limit leaving the allowed Z^' } mass to be close to two times of the DM mass. Implications for pp → Z^' } → 2ℓ and pp → 2ℓ + Z^' }, and muon g-2 anomaly are also studied.

Symmetry breaking, and the effect of matter density on neutrino oscillation

NASA Astrophysics Data System (ADS)

Mohseni Sadjadi, H.; Khosravi Karchi, A. P.

2018-04-01

A proposal for the neutrino mass, based on neutrino-scalar field interaction, is introduced. The scalar field is also non-minimally coupled to the Ricci scalar, and hence relates the neutrino mass to the matter density. In a dense region, the scalar field obeys the Z2 symmetry, and the neutrino is massless. In a dilute region, the Z2 symmetry breaks and neutrino acquires mass from the non-vanishing expectation value of the scalar field. We consider this scenario in the framework of a spherical dense object whose outside is a dilute region. In this background, we study the neutrino flavors oscillation, along with the consequences of the theory on oscillation length and MSW effect. This preliminary model may shed some lights on the existing anomalies within the neutrino data, concerning the different oscillating behavior of the neutrinos in regions with different densities.

Searching for axion stars and Q-balls with a terrestrial magnetometer network

DOE PAGES

Jackson Kimball, D. F.; Budker, D.; Eby, J.; ...

2018-02-08

Light (pseudo-)scalar fields are promising candidates to be the dark matter in the Universe. Under certain initial conditions in the early Universe and/or with certain types of self-interactions, they can form compact dark-matter objects such as axion stars or Q-balls. Direct encounters with such objects can be searched for by using a global network of atomic magnetometers. It is shown that for a range of masses and radii not ruled out by existing observations, the terrestrial encounter rate with axion stars or Q-balls can be sufficiently high (at least once per year) for a detection. Furthermore, it is shown thatmore » a global network of atomic magnetometers is sufficiently sensitive to pseudoscalar couplings to atomic spins so that a transit through an axion star or Q-ball could be detected over a broad range of unexplored parameter space.« less

Constraints on mirror models of dark matter from observable neutron-mirror neutron oscillation

NASA Astrophysics Data System (ADS)

Mohapatra, Rabindra N.; Nussinov, Shmuel

2018-01-01

The process of neutron-mirror neutron oscillation, motivated by symmetric mirror dark matter models, is governed by two parameters: n -n‧ mixing parameter δ and n -n‧ mass splitting Δ. For neutron mirror neutron oscillation to be observable, the splitting between their masses Δ must be small and current experiments lead to δ ≤ 2 ×10-27 GeV and Δ ≤10-24 GeV. We show that in mirror universe models where this process is observable, this small mass splitting constrains the way that one must implement asymmetric inflation to satisfy the limits of Big Bang Nucleosynthesis on the number of effective light degrees of freedom. In particular we find that if asymmetric inflation is implemented by inflaton decay to color or electroweak charged particles, the oscillation is unobservable. Also if one uses SM singlet fields for this purpose, they must be weakly coupled to the SM fields.

Searching for axion stars and Q -balls with a terrestrial magnetometer network

NASA Astrophysics Data System (ADS)

Jackson Kimball, D. F.; Budker, D.; Eby, J.; Pospelov, M.; Pustelny, S.; Scholtes, T.; Stadnik, Y. V.; Weis, A.; Wickenbrock, A.

2018-02-01

Light (pseudo-)scalar fields are promising candidates to be the dark matter in the Universe. Under certain initial conditions in the early Universe and/or with certain types of self-interactions, they can form compact dark-matter objects such as axion stars or Q -balls. Direct encounters with such objects can be searched for by using a global network of atomic magnetometers. It is shown that for a range of masses and radii not ruled out by existing observations, the terrestrial encounter rate with axion stars or Q -balls can be sufficiently high (at least once per year) for a detection. Furthermore, it is shown that a global network of atomic magnetometers is sufficiently sensitive to pseudoscalar couplings to atomic spins so that a transit through an axion star or Q -ball could be detected over a broad range of unexplored parameter space.

Searching for axion stars and Q-balls with a terrestrial magnetometer network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jackson Kimball, D. F.; Budker, D.; Eby, J.

Light (pseudo-)scalar fields are promising candidates to be the dark matter in the Universe. Under certain initial conditions in the early Universe and/or with certain types of self-interactions, they can form compact dark-matter objects such as axion stars or Q-balls. Direct encounters with such objects can be searched for by using a global network of atomic magnetometers. It is shown that for a range of masses and radii not ruled out by existing observations, the terrestrial encounter rate with axion stars or Q-balls can be sufficiently high (at least once per year) for a detection. Furthermore, it is shown thatmore » a global network of atomic magnetometers is sufficiently sensitive to pseudoscalar couplings to atomic spins so that a transit through an axion star or Q-ball could be detected over a broad range of unexplored parameter space.« less

Energy resolution and efficiency of phonon-mediated kinetic inductance detectors for light detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cardani, L., E-mail: laura.cardani@roma1.infn.it; Physics Department, Princeton University, Washington Road, 08544, Princeton, New Jersey; Colantoni, I.

The development of sensitive cryogenic light detectors is of primary interest for bolometric experiments searching for rare events like dark matter interactions or neutrino-less double beta decay. Thanks to their good energy resolution and the natural multiplexed read-out, Kinetic Inductance Detectors (KIDs) are particularly suitable for this purpose. To efficiently couple KIDs-based light detectors to the large crystals used by the most advanced bolometric detectors, active surfaces of several cm{sup 2} are needed. For this reason, we are developing phonon-mediated detectors. In this paper, we present the results obtained with a prototype consisting of four 40 nm thick aluminum resonators patternedmore » on a 2 × 2 cm{sup 2} silicon chip, and calibrated with optical pulses and X-rays. The detector features a noise resolution σ{sub E} = 154 ± 7 eV and an (18 ± 2)% efficiency.« less

Fine structure constant defines visual transparency of graphene.

PubMed

Nair, R R; Blake, P; Grigorenko, A N; Novoselov, K S; Booth, T J; Stauber, T; Peres, N M R; Geim, A K

2008-06-06

There are few phenomena in condensed matter physics that are defined only by the fundamental constants and do not depend on material parameters. Examples are the resistivity quantum, h/e2 (h is Planck's constant and e the electron charge), that appears in a variety of transport experiments and the magnetic flux quantum, h/e, playing an important role in the physics of superconductivity. By and large, sophisticated facilities and special measurement conditions are required to observe any of these phenomena. We show that the opacity of suspended graphene is defined solely by the fine structure constant, a = e2/hc feminine 1/137 (where c is the speed of light), the parameter that describes coupling between light and relativistic electrons and that is traditionally associated with quantum electrodynamics rather than materials science. Despite being only one atom thick, graphene is found to absorb a significant (pa = 2.3%) fraction of incident white light, a consequence of graphene's unique electronic structure.

Excitons in atomically thin 2D semiconductors and their applications

NASA Astrophysics Data System (ADS)

Xiao, Jun; Zhao, Mervin; Wang, Yuan; Zhang, Xiang

2017-06-01

The research on emerging layered two-dimensional (2D) semiconductors, such as molybdenum disulfide (MoS2), reveals unique optical properties generating significant interest. Experimentally, these materials were observed to host extremely strong light-matter interactions as a result of the enhanced excitonic effect in two dimensions. Thus, understanding and manipulating the excitons are crucial to unlocking the potential of 2D materials for future photonic and optoelectronic devices. In this review, we unravel the physical origin of the strong excitonic effect and unique optical selection rules in 2D semiconductors. In addition, control of these excitons by optical, electrical, as well as mechanical means is examined. Finally, the resultant devices such as excitonic light emitting diodes, lasers, optical modulators, and coupling in an optical cavity are overviewed, demonstrating how excitons can shape future 2D optoelectronics.

Relativistic quantum optics: The relativistic invariance of the light-matter interaction models

NASA Astrophysics Data System (ADS)

Martín-Martínez, Eduardo; Rodriguez-Lopez, Pablo

2018-05-01

In this article we discuss the invariance under general changes of reference frame of all the physical predictions of particle detector models in quantum field theory in general and, in particular, of those used in quantum optics to model atoms interacting with light. We find explicitly how the light-matter interaction Hamiltonians change under general coordinate transformations, and analyze the subtleties of the Hamiltonians commonly used to describe the light-matter interaction when relativistic motion is taken into account.

On the Direct Detection of Dark Matter Annihilation

DOE PAGES

Cherry, John Francis Jr.; Frandsen, Mads T.; Shoemaker, Ian M.

2015-06-12

We investigate the direct detection phenomenology of a class of dark matter (DM) models in which DM does not directly interact with nuclei, but rather, the products of its annihilation do. When these annihilation products are very light compared to the DM mass, the scattering in direct detection experiments is controlled by relativistic kinematics. This results in a distinctive recoil spectrum, a nonstandard and/or even absent annual modulation, and the ability to probe DM masses as low as a ~ 10 MeV. Here, we use current LUX data to show that experimental sensitivity to thermal relic annihilation cross sections hasmore » already been reached in a class of models. Moreover, the compatibility of dark matter direct detection experiments can be compared directly in E min space without making assumptions about DM astrophysics, mass, or scattering form factors. Lastly, when DM has direct couplings to nuclei, the limit from annihilation to relativistic particlesin the Sun can be stronger than that of conventional nonrelativistic direct detection by more than 3 orders of magnitude for masses in a 2–7 GeV window.« less

`Un-Darkening' the Cosmos: New laws of physics for an expanding universe

NASA Astrophysics Data System (ADS)

George, William

2017-11-01

Dark matter is believed to exist because Newton's Laws are inconsistent with the visible matter in galaxies. Dark energy is necessary to explain the universe expansion. (also available from www.turbulence-online.com) suggested that the equations themselves might be in error because they implicitly assume that time is measured in linear increments. This presentation couples the possible non-linearity of time with an expanding universe. Maxwell's equations for an expanding universe with constant speed of light are shown to be invariant only if time itself is non-linear. Both linear and exponential expansion rates are considered. A linearly expanding universe corresponds to logarithmic time, while exponential expansion corresponds to exponentially varying time. Revised Newton's laws using either leads to different definitions of mass and kinetic energy, both of which appear time-dependent if expressed in linear time. And provide the possibility of explaining the astronomical observations without either dark matter or dark energy. We would have never noticed the differences on earth, since the leading term in both expansions is linear in δ /to where to is the current age.

Cosmology in bimetric theory with an effective composite coupling to matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gümrükçüoğlu, A. Emir; Heisenberg, Lavinia; Mukohyama, Shinji

We study the cosmology of bimetric theory with a composite matter coupling. We find two possible branches of background evolution. We investigate the question of stability of cosmological perturbations. For the tensor and vector perturbations, we derive conditions on the absence of ghost and gradient instabilities. For the scalar modes, we obtain conditions for avoiding ghost degrees. In the first branch, we find that one of the scalar modes becomes a ghost at the late stages of the evolution. Conversely, this problem can be avoided in the second branch. However, we also find that the constraint for the second branchmore » prevents the doubly coupled matter fields from being the standard ingredients of cosmology. We thus conclude that a realistic and stable cosmological model requires additional minimally coupled matter fields.« less

Dark matter as ultralight axion-like particle in E6 × U(1)X GUT with QCD axion

NASA Astrophysics Data System (ADS)

Corianò, Claudio; Frampton, Paul H.

2018-07-01

Axion-like fields are naturally generated by a mechanism of anomaly cancellation of one or more anomalous gauge abelian symmetries at the Planck scale, emerging as duals of a two-form from the massless bosonic sector of string theory. This suggests an analogy of the Green-Schwarz mechanism of anomaly cancellation, at field theory level, which results in one or more Stueckelberg pseudoscalars. In the case of a single Stueckelberg pseudoscalar b, vacuum misalignments at phase transitions in the early Universe at the GUT scale provide a small mass - due to instanton suppression of the periodic potential - for a component of b, denoted as χ and termed the "axi-Higgs", which is a physical axion-like particle. The coupling of the axi-Higgs to the gauge sector via Wess-Zumino terms is suppressed by the Planck mass, which guarantees its decoupling, while its angle of misalignment is related to MGUT. We build a gauged E6 × U (1) model with anomalous U (1). It contains both an automatic invisible QCD axion and an ultra-light axi-Higgs. The invisible axion present in the model solves the strong CP problem and has mass in the conventional range while the axi-Higgs, which can act as dark matter, is sufficiently light (10-22 eV

Analysis of Ni-HYDRIDE Thin Film after Surface Plasmon Generation by Laser Technique

NASA Astrophysics Data System (ADS)

Violante, V.; Castagna, E.; Sibilia, C.; Paoloni, S.; Sarto, F.

2005-12-01

A nickel hydride thin film was studied by the attenuated total reflection method. The differences in behavior between a "black" film, and a pure nickel film "blank," are shown. The black nickel hydride film has been obtained by a short electrolysis with 1 M Li2SO4 electrolyte in light water, A shift in the minimum of the observed reflected light occurs, together with a change in the minimum shape (i.e. its half-height width increases). These two phenomenon are due to the change in the electronic band structure of the metal induced by electrons added to the lattice by hydrogen. The change of the electronic structure, revealed by the laser coupling conditions, leads us to consider that a hydride phase was created. Both the blank (not hydrogenated) and black (hydrogenated) specimens were taken under He-Ne laser beam at the reflectance minimum angle for about three hours. A SIMS analysis was also implemented to reveal differences in the isotopic composition of Cu, as marker element between the blank and black films, in order to study the coupled effect of electrolysis and plasmon-polariton excitation on LENR processes in condensed matter.

Stabilization of photon collapse and revival dynamics by a non-Markovian phonon bath

NASA Astrophysics Data System (ADS)

Carmele, Alexander; Knorr, Andreas; Milde, Frank

2013-10-01

Solid state-based light emitters such as semiconductor quantum dots (QDs) have been demonstrated to be versatile candidates to study the fundamentals of light-matter interaction. In contrast to optics with isolated atomic systems, in the solid-state dissipative processes are induced by the inherent coupling to the environment and are typically perceived as a major obstacle toward stable performances in experiments and applications. In this theoretical model study we show that this is not necessarily the case. In fact, in certain parameter regimes, the memory of the solid-state environment can enhance coherent quantum optical effects. In particular, we demonstrate that the non-Markovian coupling to an incoherent phonon bath can exhibit a stabilizing effect on the coherent QD cavity-quantum electrodynamics by inhibiting irregular oscillations and allowing for regular collapse and revival patterns. For self-assembled GaAs/InAs QDs at low photon numbers we predict dynamics that deviate dramatically from the well-known atomic Jaynes-Cummings model. Even if the required sample parameters are not yet available in recent experimental achievements, we believe our proposal opens the way to a systematic and deliberate design of photon quantum effects via specifically engineered solid-state environments.

Reconciling large- and small-scale structure in Twin Higgs models

DOE PAGES

Prilepina, Valentina; Tsai, Yuhsin

2017-09-08

Here, we study possible extensions of the Twin Higgs model that solve the Hierarchy problem and simultaneously address problems of the large- and small-scale structures of the Universe. Besides naturally providing dark matter (DM) candidates as the lightest charged twin fermions, the twin sector contains a light photon and neutrinos, which can modify structure formation relative to the prediction from the ΛCDM paradigm. We focus on two viable scenarios. First, we study a Fraternal Twin Higgs model in which the spin-3/2 baryonmore » $$\\hat{Ω}$$~($$\\hat{b}$$$\\hat{b}$$$\\hat{b}$$) and the lepton twin tau $$\\hat{τ}$$ contribute to the dominant and subcomponent dark matter densities. A non-decoupled scattering between the twin tau and twin neutrino arising from a gauged twin lepton number symmetry provides a drag force that damps the density inhomogeneity of a dark matter subcomponent. Next, we consider the possibility of introducing a twin hydrogen atom $$\\hat{H}$$ as the dominant DM component. After recombination, a small fraction of the twin protons and leptons remains ionized during structure formation, and their scattering to twin neutrinos through a gauged U(1) B-L force provides the mechanism that damps the density inhomogeneity. Both scenarios realize the Partially Acoustic dark matter (PAcDM) scenario and explain the σ 8 discrepancy between the CMB and weak lensing results. Moreover, the self-scattering neutrino behaves as a dark fluid that enhances the size of the Hubble rate H 0 to accommodate the local measurement result while satisfying the CMB constraint. For the small-scale structure, the scattering of $$\\hat{Ω}$$ ’s and $$\\hat{H}$$’s through the twin photon exchange generates a self-interacting dark matter (SIDM) model that solves the mass deficit problem from dwarf galaxy to galaxy cluster scales. Furthermore, when varying general choices of the twin photon coupling, bounds from the dwarf galaxy and the cluster merger observations can set an upper limit on the twin electric coupling.« less

Reconciling large- and small-scale structure in Twin Higgs models

NASA Astrophysics Data System (ADS)

Prilepina, Valentina; Tsai, Yuhsin

2017-09-01

We study possible extensions of the Twin Higgs model that solve the Hierarchy problem and simultaneously address problems of the large- and small-scale structures of the Universe. Besides naturally providing dark matter (DM) candidates as the lightest charged twin fermions, the twin sector contains a light photon and neutrinos, which can modify structure formation relative to the prediction from the ΛCDM paradigm. We focus on two viable scenarios. First, we study a Fraternal Twin Higgs model in which the spin-3/2 baryon \\widehat{Ω}˜ (\\widehat{b}\\widehat{b}\\widehat{b}) and the lepton twin tau \\widehat{τ} contribute to the dominant and subcomponent dark matter densities. A non-decoupled scattering between the twin tau and twin neutrino arising from a gauged twin lepton number symmetry provides a drag force that damps the density inhomogeneity of a dark matter subcomponent. Next, we consider the possibility of introducing a twin hydrogen atom Ĥ as the dominant DM component. After recombination, a small fraction of the twin protons and leptons remains ionized during structure formation, and their scattering to twin neutrinos through a gauged U(1) B-L force provides the mechanism that damps the density inhomogeneity. Both scenarios realize the Partially Acoustic dark matter (PAcDM) scenario and explain the σ 8 discrepancy between the CMB and weak lensing results. Moreover, the self-scattering neutrino behaves as a dark fluid that enhances the size of the Hubble rate H 0 to accommodate the local measurement result while satisfying the CMB constraint. For the small-scale structure, the scattering of \\widehat{Ω} 's and Ĥ's through the twin photon exchange generates a self-interacting dark matter (SIDM) model that solves the mass deficit problem from dwarf galaxy to galaxy cluster scales. Furthermore, when varying general choices of the twin photon coupling, bounds from the dwarf galaxy and the cluster merger observations can set an upper limit on the twin electric coupling.

SERS study of surface plasmon resonance induced carrier movement in Au@Cu2O core-shell nanoparticles

NASA Astrophysics Data System (ADS)

Chen, Lei; Zhang, Fan; Deng, Xin-Yu; Xue, Xiangxin; Wang, Li; Sun, Yantao; Feng, Jing-Dong; Zhang, Yongjun; Wang, Yaxin; Jung, Young Mee

2018-01-01

A plasmon induced carrier movement enhanced mechanism of surface-enhanced Raman scattering (SERS) was investigated using a charge-transfer (CT) enhancement mechanism. Here, we designed a strategy to study SERS in Au@Cu2O nanoshell nanoparticles with different shell thicknesses. Among the plasmonically coupled nanostructures, Au spheres with Cu2O shells have been of special interest due to their ultrastrong electromagnetic fields and controllable carrier transfer properties, which are useful for SERS. Au@Cu2O nanoshell nanoparticles (NPs) with shell thicknesses of 48-56 nm are synthesized that exhibit high SERS activity. This high activity originates from plasmonic-induced carrier transfer from Au@Cu2O to 4-mercaptobenzoic acid (MBA). The CT transition from the valence band (VB) of Cu2O to the second excited π-π* transition of MBA, and is of b2 electronic symmetry, which was enhanced significantly. The Herzberg-Teller selection rules were employed to predict the observed enhanced b2 symmetry modes. The system constructed in this study combines the long-range electromagnetic effect of Au NPs, localized surface plasmon resonance (LSPR) of the Au@Cu2O nanoshell, and the CT contribution to assist in understanding the SERS mechanism based on LSPR-induced carrier movement in metal/semiconductor nanocomposites.

Collider detection of dark matter electromagnetic anapole moments

NASA Astrophysics Data System (ADS)

Alves, Alexandre; Santos, A. C. O.; Sinha, Kuver

2018-03-01

Dark matter that interacts with the Standard Model by exchanging photons through higher multipole interactions occurs in a wide range of both strongly and weakly coupled hidden sector models. We study the collider detection prospects of these candidates, with a focus on Majorana dark matter that couples through the anapole moment. The study is conducted at the effective field theory level with the mono-Z signature incorporating varying levels of systematic uncertainties at the high-luminosity LHC. The projected collider reach on the anapole moment is then compared to the reach coming from direct detection experiments like LZ. Finally, the analysis is applied to a weakly coupled completion with leptophilic dark matter.

The coupling to matter in massive, bi- and multi-gravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Noller, Johannes; Melville, Scott, E-mail: noller@physics.ox.ac.uk, E-mail: scott.melville@queens.ox.ac.uk

2015-01-01

In this paper we construct a family of ways in which matter can couple to one or more 'metrics'/spin-2 fields in the vielbein formulation. We do so subject to requiring the weak equivalence principle and the absence of ghosts from pure spin-2 interactions generated by the matter action. Results are presented for Massive, Bi- and Multi-Gravity theories and we give explicit expressions for the effective matter metric in all of these cases.

Observational constraints on varying neutrino-mass cosmology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geng, Chao-Qiang; Lee, Chung-Chi; Myrzakulov, R.

We consider generic models of quintessence and we investigate the influence of massive neutrino matter with field-dependent masses on the matter power spectrum. In case of minimally coupled neutrino matter, we examine the effect in tracker models with inverse power-law and double exponential potentials. We present detailed investigations for the scaling field with a steep exponential potential, non-minimally coupled to massive neutrino matter, and we derive constraints on field-dependent neutrino masses from the observational data.

A global fit of the γ-ray galactic center excess within the scalar singlet Higgs portal model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cuoco, Alessandro; Eiteneuer, Benedikt; Heisig, Jan

2016-06-28

We analyse the excess in the γ-ray emission from the center of our galaxy observed by Fermi-LAT in terms of dark matter annihilation within the scalar Higgs portal model. In particular, we include the astrophysical uncertainties from the dark matter distribution and allow for unspecified additional dark matter components. We demonstrate through a detailed numerical fit that the strength and shape of the γ-ray spectrum can indeed be described by the model in various regions of dark matter masses and couplings. Constraints from invisible Higgs decays, direct dark matter searches, indirect searches in dwarf galaxies and for γ-ray lines, andmore » constraints from the dark matter relic density reduce the parameter space to dark matter masses near the Higgs resonance. We find two viable regions: one where the Higgs-dark matter coupling is of O(10{sup −2}), and an additional dark matter component beyond the scalar WIMP of our model is preferred, and one region where the Higgs-dark matter coupling may be significantly smaller, but where the scalar WIMP constitutes a significant fraction or even all of dark matter. Both viable regions are hard to probe in future direct detection and collider experiments.« less

Low-threshold indium gallium nitride quantum dot microcavity lasers

NASA Astrophysics Data System (ADS)

Woolf, Alexander J.

Gallium nitride (GaN) microcavities with embedded optical emitters have long been sought after as visible light sources as well as platforms for cavity quantum electrodynamics (cavity QED) experiments. Specifically, materials containing indium gallium nitride (InGaN) quantum dots (QDs) offer an outstanding platform to study light matter interactions and realize practical devices, such as on-chip light emitting diodes and nanolasers. Inherent advantages of nitride-based microcavities include low surface recombination velocities, enhanced room-temperature performance (due to their high exciton binding energy, as high as 67 meV for InGaN QDs), and emission wavelengths in the blue region of the visible spectrum. In spite of these advantages, several challenges must be overcome in order to capitalize on the potential of this material system. Such diffculties include the processing of GaN into high-quality devices due to the chemical inertness of the material, low material quality as a result of strain-induced defects, reduced carrier recombination effciencies due to internal fields, and a lack of characterization of the InGaN QDs themselves due to the diffculty of their growth and therefore lack of development relative to other semiconductor QDs. In this thesis we seek to understand and address such issues by investigating the interaction of light coupled to InGaN QDs via a GaN microcavity resonator. Such coupling led us to the demonstration of the first InGaN QD microcavity laser, whose performance offers insights into the properties and current limitations of the nitride materials and their emitters. This work is organized into three main sections. Part I outlines the key advantages and challenges regarding indium gallium nitride (InGaN) emitters embedded within gallium nitride (GaN) optical microcavities. Previous work is also discussed which establishes context for the work presented here. Part II includes the fundamentals related to laser operation, including the derivation and analysis of the laser rate equations. A thorough examination of the rate equations serves as a natural motivation for QDs and high-quality factor low-modal volume resonators as an optimal laser gain medium and cavity, respectively. The combination of the two theoretically yields the most efficient semiconductor laser device possible. Part III describes in detail the design, growth, fabrication and characterization of the first InGaN QD microcavity laser. Additional experiments are also conducted in order to conclusively prove that the InGaN QDs serve as the gain medium and facilitate laser oscillation within the microdisk cavities. Part III continues with work related towards the development of the next generation of nitride light emitting devices. This includes the realization of photonic crystal cavity (PCC) fragmented quantum well (FQW) lasers that exhibit record low lasing thresholds of 9.1 muJ/cm2, comparable to the best devices in other III-V material systems. Part III also discusses cavity QED experiments on InGaN QDs embedded within GaN PCCs in order to quantify the degree of light-matter interaction. The lack of experimental evidence for weak or strong coupling, in the form of the Purcell Effect or cavity-mode anti-crossing respectively, naturally motivates the question of what mechanism is limiting the device performance. Part III concludes with cathodoluminesence and tapered fiber measurements in order to identify the limiting factor towards achieving strong coupling between InGaN QDs and GaN microcavities.

SOIL NITROGEN TRANSFORMATIONS AND ROLE OF LIGHT FRACTION ORGANIC MATTER IN FOREST SOILS

EPA Science Inventory

Depletion of soil organic matter through cultivation may alter substrate availability for microbes, altering the dynamic balance between nitrogen (N) immobilization and mineralization. Soil light fraction (LF) organic matter is an active pool that decreases upon cultivation, and...

Non-minimal derivative couplings of the composite metric

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heisenberg, Lavinia, E-mail: laviniah@kth.se

2015-11-01

In the context of massive gravity, bi-gravity and multi-gravity non-minimal matter couplings via a specific composite effective metric were investigated recently. Even if these couplings generically reintroduce the Boulware-Deser ghost, this composite metric is unique in the sense that the ghost reemerges only beyond the decoupling limit and the matter quantum loop corrections do not detune the potential interactions. We consider non-minimal derivative couplings of the composite metric to matter fields for a specific subclass of Horndeski scalar-tensor interactions. We first explore these couplings in the mini-superspace and investigate in which scenario the ghost remains absent. We further study thesemore » non-minimal derivative couplings in the decoupling-limit of the theory and show that the equation of motion for the helicity-0 mode remains second order in derivatives. Finally, we discuss preliminary implications for cosmology.« less

Non-minimal derivative couplings of the composite metric

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heisenberg, Lavinia; Department of Physics & The Oskar Klein Centre,AlbaNova University Centre, 10691 Stockholm

2015-11-04

In the context of massive gravity, bi-gravity and multi-gravity non-minimal matter couplings via a specific composite effective metric were investigated recently. Even if these couplings generically reintroduce the Boulware-Deser ghost, this composite metric is unique in the sense that the ghost reemerges only beyond the decoupling limit and the matter quantum loop corrections do not detune the potential interactions. We consider non-minimal derivative couplings of the composite metric to matter fields for a specific subclass of Horndeski scalar-tensor interactions. We first explore these couplings in the mini-superspace and investigate in which scenario the ghost remains absent. We further study thesemore » non-minimal derivative couplings in the decoupling-limit of the theory and show that the equation of motion for the helicity-0 mode remains second order in derivatives. Finally, we discuss preliminary implications for cosmology.« less

Recognizing Axionic Dark Matter by Compton and de Broglie Scale Modulation of Pulsar Timing.

PubMed

De Martino, Ivan; Broadhurst, Tom; Tye, S-H Henry; Chiueh, Tzihong; Schive, Hsi-Yu; Lazkoz, Ruth

2017-12-01

Light axionic dark matter, motivated by string theory, is increasingly favored for the "no weakly interacting massive particle era". Galaxy formation is suppressed below a Jeans scale of ≃10^{8}  M_{⊙} by setting the axion mass to m_{B}∼10^{-22}  eV, and the large dark cores of dwarf galaxies are explained as solitons on the de Broglie scale. This is persuasive, but detection of the inherent scalar field oscillation at the Compton frequency ω_{B}=(2.5  months)^{-1}(m_{B}/10^{-22}  eV) would be definitive. By evolving the coupled Schrödinger-Poisson equation for a Bose-Einstein condensate, we predict the dark matter is fully modulated by de Broglie interference, with a dense soliton core of size ≃150  pc, at the Galactic center. The oscillating field pressure induces general relativistic time dilation in proportion to the local dark matter density and pulsars within this dense core have detectably large timing residuals of ≃400  nsec/(m_{B}/10^{-22}  eV). This is encouraging as many new pulsars should be discovered near the Galactic center with planned radio surveys. More generally, over the whole Galaxy, differences in dark matter density between pairs of pulsars imprints a pairwise Galactocentric signature that can be distinguished from an isotropic gravitational wave background.

Limits on Spin-independent Couplings of Light Dark Matter WIMPs with a p-type Point-contact Germanium Detector

NASA Astrophysics Data System (ADS)

Lin, S. T.; Wong, H. T.

New limits on spin-independent WIMP-nucleon coupling using 39.5 kg-days of data taken with a p-type point-contact germanium detector with fiducial mass of 840 g at the Kuo-Sheng Reactor Neutrino Laboratory (KSNL) is presented. Charactering and understanding the anomalous surface behaviour is of particular significance to this study. The slow rise-time of surface events is identified via software pulse shape analysis techniques. In addition, the signal-retaining and background-rejecting efficiencies are implied to clarify the actual bulk and surface events in the mixed regime at sub-keV range. Both efficiencies are evaluated with calibration sources and a novel n-type point-contact germanium detector. Efficiencies-corrected background spectra from the low-background facility at KSNL are derived. Part of the parameter space in cross-section versus WIMP-mass is probed and excluded.

Atoms and molecules in cavities, from weak to strong coupling in quantum-electrodynamics (QED) chemistry

PubMed Central

Flick, Johannes; Ruggenthaler, Michael; Appel, Heiko

2017-01-01

In this work, we provide an overview of how well-established concepts in the fields of quantum chemistry and material sciences have to be adapted when the quantum nature of light becomes important in correlated matter–photon problems. We analyze model systems in optical cavities, where the matter–photon interaction is considered from the weak- to the strong-coupling limit and for individual photon modes as well as for the multimode case. We identify fundamental changes in Born–Oppenheimer surfaces, spectroscopic quantities, conical intersections, and efficiency for quantum control. We conclude by applying our recently developed quantum-electrodynamical density-functional theory to spontaneous emission and show how a straightforward approximation accurately describes the correlated electron–photon dynamics. This work paves the way to describe matter–photon interactions from first principles and addresses the emergence of new states of matter in chemistry and material science. PMID:28275094

SERS of Individual Nanoparticles on a Mirror: Size Does Matter, but so Does Shape

PubMed Central

2016-01-01

Coupling noble metal nanoparticles by a 1 nm gap to an underlying gold mirror confines light to extremely small volumes, useful for sensing on the nanoscale. Individually measuring 10 000 of such gold nanoparticles of increasing size dramatically shows the different scaling of their optical scattering (far-field) and surface-enhanced Raman emission (SERS, near-field). Linear red-shifts of the coupled plasmon modes are seen with increasing size, matching theory. The total SERS from the few hundred molecules under each nanoparticle dramatically increases with increasing size. This scaling shows that maximum SERS emission is always produced from the largest nanoparticles, irrespective of tuning to any plasmonic resonances. Changes of particle facet with nanoparticle size result in vastly weaker scaling of the near-field SERS, without much modifying the far-field, and allows simple approaches for optimizing practical sensing. PMID:27223478

SERS of Individual Nanoparticles on a Mirror: Size Does Matter, but so Does Shape.

PubMed

Benz, Felix; Chikkaraddy, Rohit; Salmon, Andrew; Ohadi, Hamid; de Nijs, Bart; Mertens, Jan; Carnegie, Cloudy; Bowman, Richard W; Baumberg, Jeremy J

2016-06-16

Coupling noble metal nanoparticles by a 1 nm gap to an underlying gold mirror confines light to extremely small volumes, useful for sensing on the nanoscale. Individually measuring 10 000 of such gold nanoparticles of increasing size dramatically shows the different scaling of their optical scattering (far-field) and surface-enhanced Raman emission (SERS, near-field). Linear red-shifts of the coupled plasmon modes are seen with increasing size, matching theory. The total SERS from the few hundred molecules under each nanoparticle dramatically increases with increasing size. This scaling shows that maximum SERS emission is always produced from the largest nanoparticles, irrespective of tuning to any plasmonic resonances. Changes of particle facet with nanoparticle size result in vastly weaker scaling of the near-field SERS, without much modifying the far-field, and allows simple approaches for optimizing practical sensing.

Observation of the exceptional point in cavity magnon-polaritons.

PubMed

Zhang, Dengke; Luo, Xiao-Qing; Wang, Yi-Pu; Li, Tie-Fu; You, J Q

2017-11-08

Magnon-polaritons are hybrid light-matter quasiparticles originating from the strong coupling between magnons and photons. They have emerged as a potential candidate for implementing quantum transducers and memories. Owing to the dampings of both photons and magnons, the polaritons have limited lifetimes. However, stationary magnon-polariton states can be reached by a dynamical balance between pumping and losses, so the intrinsically nonequilibrium system may be described by a non-Hermitian Hamiltonian. Here we design a tunable cavity quantum electrodynamics system with a small ferromagnetic sphere in a microwave cavity and engineer the dissipations of photons and magnons to create cavity magnon-polaritons which have non-Hermitian spectral degeneracies. By tuning the magnon-photon coupling strength, we observe the polaritonic coherent perfect absorption and demonstrate the phase transition at the exceptional point. Our experiment offers a novel macroscopic quantum platform to explore the non-Hermitian physics of the cavity magnon-polaritons.

Self-homodyne measurement of a dynamic Mollow triplet in the solid state

NASA Astrophysics Data System (ADS)

Fischer, Kevin A.; Müller, Kai; Rundquist, Armand; Sarmiento, Tomas; Piggott, Alexander Y.; Kelaita, Yousif; Dory, Constantin; Lagoudakis, Konstantinos G.; Vučković, Jelena

2016-03-01

The study of the light-matter interaction at the quantum scale has been enabled by the cavity quantum electrodynamics (CQED) architecture, in which a quantum two-level system strongly couples to a single cavity mode. Originally implemented with atoms in optical cavities, CQED effects are now also observed with artificial atoms in solid-state environments. Such realizations of these systems exhibit fast dynamics, making them attractive candidates for devices including modulators and sources in high-throughput communications. However, these systems possess large photon out-coupling rates that obscure any quantum behaviour at large excitation powers. Here, we have used a self-homodyning interferometric technique that fully employs the complex mode structure of our nanofabricated cavity to observe a quantum phenomenon known as the dynamic Mollow triplet. We expect this interference to facilitate the development of arbitrary on-chip quantum state generators, thereby strongly influencing quantum lithography, metrology and imaging.

An ultra-weak sector, the strong CP problem and the pseudo-Goldstone dilaton

DOE PAGES

Allison, Kyle; Hill, Christopher T.; Ross, Graham G.

2014-12-29

In the context of a Coleman–Weinberg mechanism for the Higgs boson mass, we address the strong CP problem. We show that a DFSZ-like invisible axion model with a gauge-singlet complex scalar field S, whose couplings to the Standard Model are naturally ultra-weak, can solve the strong CP problem and simultaneously generate acceptable electroweak symmetry breaking. The ultra-weak couplings of the singlet S are associated with underlying approximate shift symmetries that act as custodial symmetries and maintain technical naturalness. The model also contains a very light pseudo-Goldstone dilaton that is consistent with cosmological Polonyi bounds, and the axion can be themore » dark matter of the universe. As a result, we further outline how a SUSY version of this model, which may be required in the context of Grand Unification, can avoid introducing a hierarchy problem.« less

An ultra-weak sector, the strong CP problem and the pseudo-Goldstone dilaton

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allison, Kyle; Hill, Christopher T.; Ross, Graham G.

In the context of a Coleman–Weinberg mechanism for the Higgs boson mass, we address the strong CP problem. We show that a DFSZ-like invisible axion model with a gauge-singlet complex scalar field S, whose couplings to the Standard Model are naturally ultra-weak, can solve the strong CP problem and simultaneously generate acceptable electroweak symmetry breaking. The ultra-weak couplings of the singlet S are associated with underlying approximate shift symmetries that act as custodial symmetries and maintain technical naturalness. The model also contains a very light pseudo-Goldstone dilaton that is consistent with cosmological Polonyi bounds, and the axion can be themore » dark matter of the universe. As a result, we further outline how a SUSY version of this model, which may be required in the context of Grand Unification, can avoid introducing a hierarchy problem.« less

Cutoff for extensions of massive gravity and bi-gravity

NASA Astrophysics Data System (ADS)

Matas, Andrew

2016-04-01

Recently there has been interest in extending ghost-free massive gravity, bi-gravity, and multi-gravity by including non-standard kinetic terms and matter couplings. We first review recent proposals for this class of extensions, emphasizing how modifications of the kinetic and potential structure of the graviton and modifications of the coupling to matter are related. We then generalize existing no-go arguments in the metric language to the vielbein language in second-order form. We give an ADM argument to show that the most promising extensions to the kinetic term and matter coupling contain a Boulware-Deser ghost. However, as recently emphasized, we may still be able to view these extensions as effective field theories below some cutoff scale. To address this possibility, we show that there is a decoupling limit where a ghost appears for a wide class of matter couplings and kinetic terms. In particular, we show that there is a decoupling limit where the linear effective vielbein matter coupling contains a ghost. Using the insight we gain from this decoupling limit analysis, we place an upper bound on the cutoff for the linear effective vielbein coupling. This result can be generalized to new kinetic interactions in the vielbein language in second-order form. Combined with recent results, this provides a strong uniqueness argument on the form of ghost-free massive gravity, bi-gravity, and multi-gravity.

Does Sex Really Matter? Examining the Connections Between Spouses' Nonsexual Behaviors, Sexual Frequency, Sexual Satisfaction, and Marital Satisfaction.

PubMed

Schoenfeld, Elizabeth A; Loving, Timothy J; Pope, Mark T; Huston, Ted L; Štulhofer, Aleksandar

2017-02-01

We examined the interplay between husbands' and wives' positive and negative nonsexual interpersonal behaviors, frequency of sexual intercourse, sexual satisfaction, and feelings of marital satisfaction. To do this, we conducted an in-depth face-to-face interview and completed a series of telephone diaries with 105 couples during their second, third, and fourteenth years of marriage. Consistent with the argument that women's sexual response is tied to intimacy (Basson, 2000), multilevel analyses revealed that husbands' positive interpersonal behaviors directed toward their wives-but not wives' positivity nor spouses' negative behaviors (regardless of gender)-predicted the frequency with which couples engaged in intercourse. The frequency of sexual intercourse and interpersonal negativity predicted both husbands' and wives' sexual satisfaction; wives' positive behaviors were also tied to husbands' sexual satisfaction. When spouses' interpersonal behaviors, frequency of sexual intercourse, and sexual satisfaction were considered in tandem, all but the frequency of sexual intercourse were associated with marital satisfaction. When it comes to feelings of marital satisfaction, therefore, a satisfying sex life and a warm interpersonal climate appear to matter more than does a greater frequency of sexual intercourse. Collectively, these findings shed much-needed light on the interplay between the nonsexual interpersonal climate of marriage and spouses' sexual relationships.

Spin-dependent constraints on blind spots for thermal singlino-higgsino dark matter with(out) light singlets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Badziak, Marcin; Olechowski, Marek; Szczerbiak, Paweł

The LUX experiment has recently set very strong constraints on spin-independent interactions of WIMP with nuclei. These null results can be accommodated in NMSSM provided that the effective spin-independent coupling of the LSP to nucleons is suppressed. Here, we investigate thermal relic abundance of singlino-higgsino LSP in these so-called spin-independent blind spots and derive current constraints and prospects for direct detection of spin-dependent interactions of the LSP with nuclei providing strong constraints on parameter space. We show that if the Higgs boson is the only light scalar the new LUX constraints set a lower bound on the LSP mass of about 300 GeV except for a small range around the half of Z 0 boson masses where resonant annihilation via Z 0 exchange dominates. XENON1T will probe entire range of LSP masses except for a tiny Z 0-resonant region that may be tested by the LZ experiment. These conclusions apply to general singlet-doublet dark matter annihilating dominantly tomore » $$t\\bar{t}$$. Presence of light singlet (pseudo)scalars generically relaxes the constraints because new LSP (resonant and non-resonant) annihilation channels become important. Even away from resonant regions, the lower limit on the LSP mass from LUX is relaxed to about 250 GeV while XENON1T may not be sensitive to the LSP masses above about 400 GeV.« less

Spin-dependent constraints on blind spots for thermal singlino-higgsino dark matter with(out) light singlets

DOE PAGES

Badziak, Marcin; Olechowski, Marek; Szczerbiak, Paweł

2017-07-11

The LUX experiment has recently set very strong constraints on spin-independent interactions of WIMP with nuclei. These null results can be accommodated in NMSSM provided that the effective spin-independent coupling of the LSP to nucleons is suppressed. Here, we investigate thermal relic abundance of singlino-higgsino LSP in these so-called spin-independent blind spots and derive current constraints and prospects for direct detection of spin-dependent interactions of the LSP with nuclei providing strong constraints on parameter space. We show that if the Higgs boson is the only light scalar the new LUX constraints set a lower bound on the LSP mass of about 300 GeV except for a small range around the half of Z 0 boson masses where resonant annihilation via Z 0 exchange dominates. XENON1T will probe entire range of LSP masses except for a tiny Z 0-resonant region that may be tested by the LZ experiment. These conclusions apply to general singlet-doublet dark matter annihilating dominantly tomore » $$t\\bar{t}$$. Presence of light singlet (pseudo)scalars generically relaxes the constraints because new LSP (resonant and non-resonant) annihilation channels become important. Even away from resonant regions, the lower limit on the LSP mass from LUX is relaxed to about 250 GeV while XENON1T may not be sensitive to the LSP masses above about 400 GeV.« less

Dirac equation in 2-dimensional curved spacetime, particle creation, and coupled waveguide arrays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koke, Christian, E-mail: christian.koke@stud.uni-heidelberg.de; Noh, Changsuk, E-mail: changsuk@kias.re.kr; Angelakis, Dimitris G., E-mail: dimitris.angelakis@gmail.com

When quantum fields are coupled to gravitational fields, spontaneous particle creation may occur similarly to when they are coupled to external electromagnetic fields. A gravitational field can be incorporated as a background spacetime if the back-action of matter on the field can be neglected, resulting in modifications of the Dirac or Klein–Gordon equations for elementary fermions and bosons respectively. The semi-classical description predicts particle creation in many situations, including the expanding-universe scenario, near the event horizon of a black hole (the Hawking effect), and an accelerating observer in flat spacetime (the Unruh effect). In this work, we give a pedagogicalmore » introduction to the Dirac equation in a general 2D spacetime and show examples of spinor wave packet dynamics in flat and curved background spacetimes. In particular, we cover the phenomenon of particle creation in a time-dependent metric. Photonic analogs of these effects are then proposed, where classical light propagating in an array of coupled waveguides provides a visualisation of the Dirac spinor propagating in a curved 2D spacetime background. The extent to which such a single-particle description can be said to mimic particle creation is discussed.« less

runDM: Running couplings of Dark Matter to the Standard Model

NASA Astrophysics Data System (ADS)

D'Eramo, Francesco; Kavanagh, Bradley J.; Panci, Paolo

2018-02-01

runDM calculates the running of the couplings of Dark Matter (DM) to the Standard Model (SM) in simplified models with vector mediators. By specifying the mass of the mediator and the couplings of the mediator to SM fields at high energy, the code can calculate the couplings at low energy, taking into account the mixing of all dimension-6 operators. runDM can also extract the operator coefficients relevant for direct detection, namely low energy couplings to up, down and strange quarks and to protons and neutrons.

Concept for a dark matter detector using liquid helium-4

NASA Astrophysics Data System (ADS)

Guo, W.; McKinsey, D. N.

2013-06-01

Direct searches for light dark matter particles (mass<10GeV) are especially challenging because of the low energies transferred in elastic scattering to typical heavy nuclear targets. We investigate the possibility of using liquid helium-4 as a target material, taking advantage of the favorable kinematic matching of the helium nucleus to light dark matter particles. Monte Carlo simulations are performed to calculate the charge, scintillation, and triplet helium molecule signals produced by recoil He ions, for a variety of energies and electric fields. We show that excellent background rejection might be achieved based on the ratios between different signal channels. The sensitivity of the helium-based detector to light dark matter particles is estimated for various electric fields and light collection efficiencies.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mohapi, N.; Hees, A.; Larena, J., E-mail: n.mohapi@gmail.com, E-mail: a.hees@ru.ac.za, E-mail: j.larena@ru.ac.za

The Einstein Equivalence Principle is a fundamental principle of the theory of General Relativity. While this principle has been thoroughly tested with standard matter, the question of its validity in the Dark sector remains open. In this paper, we consider a general tensor-scalar theory that allows to test the equivalence principle in the Dark sector by introducing two different conformal couplings to standard matter and to Dark matter. We constrain these couplings by considering galactic observations of strong lensing and of velocity dispersion. Our analysis shows that, in the case of a violation of the Einstein Equivalence Principle, data favourmore » violations through coupling strengths that are of opposite signs for ordinary and Dark matter. At the same time, our analysis does not show any significant deviations from General Relativity.« less

Mass eigenstates in bimetric theory with matter coupling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmidt-May, Angnis, E-mail: angnis.schmidt-may@fysik.su.se

2015-01-01

In this paper we study the ghost-free bimetric action extended by a recently proposed coupling to matter through a composite metric. The equations of motion for this theory are derived using a method which avoids varying the square-root matrix that appears in the matter coupling. We make an ansatz for which the metrics are proportional to each other and find that it can solve the equations provided that one parameter in the action is fixed. In this case, the proportional metrics as well as the effective metric that couples to matter solve Einstein's equations of general relativity including a mattermore » source. Around these backgrounds we derive the quadratic action for perturbations and diagonalize it into generalized mass eigenstates. It turns out that matter only interacts with the massless spin-2 mode whose equation of motion has exactly the form of the linearized Einstein equations, while the field with Fierz-Pauli mass term is completely decoupled. Hence, bimetric theory, with one parameter fixed such that proportional solutions exist, is degenerate with general relativity up to linear order around these backgrounds.« less

Parametrization of a nonlocal chiral quark model in the instantaneous three-flavor case. Basic formulas and tables

NASA Astrophysics Data System (ADS)

Grigorian, H.

2007-05-01

We describe the basic formulation of the parametrization scheme for the instantaneous nonlocal chiral quark model in the three-flavor case. We choose to discuss the Gaussian, Lorentzian-type, Woods-Saxon, and sharp cutoff (NJL) functional forms of the momentum dependence for the form factor of the separable interaction. The four parameters, light and strange quark masses and coupling strength (G S) and range of the interaction (Λ), have been fixed by the same phenomenological inputs: pion and kaon masses and the pion decay constant and light quark mass in vacuum. The Woods-Saxon and Lorentzian-type form factors are suitable for an interpolation between sharp cutoff and soft momentum dependence. Results are tabulated for applications in models of hadron structure and quark matter at finite temperatures and chemical potentials, where separable models have been proven successfully.

Excitons in atomically thin 2D semiconductors and their applications

DOE PAGES

Xiao, Jun; Zhao, Mervin; Wang, Yuan; ...

2017-01-01

The research on emerging layered two-dimensional (2D) semiconductors, such as molybdenum disulfide (MoS 2), reveals unique optical properties generating significant interest. Experimentally, these materials were observed to host extremely strong light-matter interactions as a result of the enhanced excitonic effect in two dimensions. Thus, understanding and manipulating the excitons are crucial to unlocking the potential of 2D materials for future photonic and optoelectronic devices. Here in this review, we unravel the physical origin of the strong excitonic effect and unique optical selection rules in 2D semiconductors. In addition, control of these excitons by optical, electrical, as well as mechanical meansmore » is examined. Finally, the resultant devices such as excitonic light emitting diodes, lasers, optical modulators, and coupling in an optical cavity are overviewed, demonstrating how excitons can shape future 2D optoelectronics.« less

Generalised nonminimally gravity-matter coupled theory

NASA Astrophysics Data System (ADS)

Bahamonde, Sebastian

2018-04-01

In this paper, a new generalised gravity-matter coupled theory of gravity is presented. This theory is constructed by assuming an action with an arbitrary function f(T,B,L_m) which depends on the scalar torsion T, the boundary term B=\

Fundamental Particle Structure in the Cosmological Dark Matter

NASA Astrophysics Data System (ADS)

Khlopov, Maxim

2013-11-01

The nonbaryonic dark matter of the universe is assumed to consist of new stable forms of matter. Their stability reflects symmetry of micro-world and mechanisms of its symmetry breaking. Particle candidates for cosmological dark matter are lightest particles that bear new conserved quantum numbers. Dark matter particles may represent ideal gas of noninteracting particles. Self-interacting dark matter weakly or superweakly coupled to ordinary matter is also possible, reflecting nontrivial pattern of particle symmetry in the hidden sector of particle theory. In the early universe the structure of particle symmetry breaking gives rise to cosmological phase transitions, from which macroscopic cosmological defects or primordial nonlinear structures can be originated. Primordial black holes (PBHs) can be not only a candidate for dark matter, but also represent a universal probe for superhigh energy physics in the early universe. Evaporating PBHs turn to be a source of even superweakly interacting particles, while clouds of massive PBHs can serve as nonlinear seeds for galaxy formation. The observed broken symmetry of the three known families may provide a simultaneous solution for the problems of the mass of neutrino and strong CP-violation in the unique framework of models of horizontal unification. Dark matter candidates can also appear in the new families of quarks and leptons and the existence of new stable charged leptons and quarks is possible, hidden in elusive "dark atoms." Such possibility, strongly restricted by the constraints on anomalous isotopes of light elements, is not excluded in scenarios that predict stable double charged particles. The excessive -2 charged particles are bound in these scenarios with primordial helium in O-helium "atoms," maintaining specific nuclear-interacting form of the dark matter, which may provide an interesting solution for the puzzles of the direct dark matter searches. In the context of cosmoparticle physics, studying fundamental relationship of micro- and macro-worlds, the problem of cosmological dark matter implies cross disciplinary theoretical, experimental and observational studies for its solution.

Scrutinizing a di-photon resonance at the LHC through Moscow zero

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arcadi, Giorgio; Ghosh, Pradipta; Centre de Physique Théorique, École Polytechnique, CNRS, Université Paris-Saclay,Palaiseau, 91128

The ATLAS and CMS collaborations have recently released their new analyses of the diphoton searches. We look in detail the consequences of their results deriving strong constraints on models where a scalar resonance s decays into two light pseudoscalars which in turn decay into two pairs of collimated photons, mis-identified with two real photons. In our construction, all mass terms are generated dynamically, and only one pair of vector-like fermions generate couplings which will be probed using the upcoming LHC data. Moreover, we show that a stable dark matter candidate, respecting the cosmological constraints, is naturally affordable in the model.

Bioenabled SERS Substrates for Food Safety and Drinking Water Monitoring.

PubMed

Yang, Jing; Rorrer, Gregory L; Wang, Alan X

2015-04-20

We present low-cost bioenabled surface-enhanced Raman scattering (SERS) substrates that can be massively produced in sustainable and eco-friendly methods with significant commercial potentials for the detection of food contamination and drinking water pollution. The sensors are based on diatom frustules with integrated plasmonic nanoparticles. The ultra-high sensitivity of the SERS substrates comes from the coupling between the diatom frustules and Ag nanoparticles to achieve dramatically increased local optical field to enhance the light-matter interactions for SERS sensing. We successfully applied the bioenabled SERS substrates to detect melamine in milk and aromatic compounds in water with sensitivity down to 1μg/L.

Bioenabled SERS substrates for food safety and drinking water monitoring

NASA Astrophysics Data System (ADS)

Yang, Jing; Rorrer, Gregory L.; Wang, Alan X.

2015-05-01

We present low-cost bioenabled surface-enhanced Raman scattering (SERS) substrates that can be massively produced in sustainable and eco-friendly methods with significant commercial potentials for the detection of food contamination and drinking water pollution. The sensors are based on diatom frustules with integrated plasmonic nanoparticles. The ultra-high sensitivity of the SERS substrates comes from the coupling between the diatom frustules and Ag nanoparticles to achieve dramatically increased local optical field to enhance the light-matter interactions for SERS sensing. We successfully applied the bioenabled SERS substrates to detect melamine in milk and aromatic compounds in water with sensitivity down to 1μg/L.

Robust Deterministic Controlled Phase-Flip Gate and Controlled-Not Gate Based on Atomic Ensembles Embedded in Double-Sided Optical Cavities

NASA Astrophysics Data System (ADS)

Liu, A.-Peng; Cheng, Liu-Yong; Guo, Qi; Zhang, Shou

2018-02-01

We first propose a scheme for controlled phase-flip gate between a flying photon qubit and the collective spin wave (magnon) of an atomic ensemble assisted by double-sided cavity quantum systems. Then we propose a deterministic controlled-not gate on magnon qubits with parity-check building blocks. Both the gates can be accomplished with 100% success probability in principle. Atomic ensemble is employed so that light-matter coupling is remarkably improved by collective enhancement. We assess the performance of the gates and the results show that they can be faithfully constituted with current experimental techniques.

Bioenabled SERS Substrates for Food Safety and Drinking Water Monitoring

PubMed Central

Yang, Jing; Rorrer, Gregory L.; Wang, Alan X.

2016-01-01

We present low-cost bioenabled surface-enhanced Raman scattering (SERS) substrates that can be massively produced in sustainable and eco-friendly methods with significant commercial potentials for the detection of food contamination and drinking water pollution. The sensors are based on diatom frustules with integrated plasmonic nanoparticles. The ultra-high sensitivity of the SERS substrates comes from the coupling between the diatom frustules and Ag nanoparticles to achieve dramatically increased local optical field to enhance the light-matter interactions for SERS sensing. We successfully applied the bioenabled SERS substrates to detect melamine in milk and aromatic compounds in water with sensitivity down to 1μg/L. PMID:26900205

Beyond Discrete Vacuum Spacetimes

NASA Astrophysics Data System (ADS)

McDonald, Jonathan; Miller, Warner

2008-04-01

In applications to pre-geometric models of quantum gravity, one expects matter to play an important role in the geometry of the spacetime. Such models often posit that the matter fields play a crucial role in the determination of the spacetime geometry. However, it is not well understood at a fundamental level how one couples matter into the Regge geometry. In order to better understand the nature of such theories that rely on Regge Calculus, we must first gain a better understanding of the role of matter in a lattice spacetime. We investigate consistent methods of incorporating matter into spacetime, and particularly focus on the role of spinors in Regge Calculus. Since spinors are fundamental to fermionic fields, this investigation is crucial in understanding fermionic coupling to discrete spacetime. Our focus is primarily on the geometric interpretation of the fields on the lattice geometry with a goal on understanding the dynamic coupling between the fields and the geometry.

Dark matter relics and the expansion rate in scalar-tensor theories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dutta, Bhaskar; Jimenez, Esteban; Zavala, Ivonne, E-mail: dutta@physics.tamu.edu, E-mail: este1985@physics.tamu.edu, E-mail: e.i.zavalacarrasco@swansea.ac.uk

We study the impact of a modified expansion rate on the dark matter relic abundance in a class of scalar-tensor theories. The scalar-tensor theories we consider are motivated from string theory constructions, which have conformal as well as disformally coupled matter to the scalar. We investigate the effects of such a conformal coupling to the dark matter relic abundance for a wide range of initial conditions, masses and cross-sections. We find that exploiting all possible initial conditions, the annihilation cross-section required to satisfy the dark matter content can differ from the thermal average cross-section in the standard case. We alsomore » study the expansion rate in the disformal case and find that physically relevant solutions require a nontrivial relation between the conformal and disformal functions. We study the effects of the disformal coupling in an explicit example where the disformal function is quadratic.« less

Universe without dark energy: Cosmic acceleration from dark matter-baryon interactions

NASA Astrophysics Data System (ADS)

Berezhiani, Lasha; Khoury, Justin; Wang, Junpu

2017-06-01

Cosmic acceleration is widely believed to require either a source of negative pressure (i.e., dark energy), or a modification of gravity, which necessarily implies new degrees of freedom beyond those of Einstein gravity. In this paper we present a third possibility, using only dark matter (DM) and ordinary matter. The mechanism relies on the coupling between dark matter and ordinary matter through an effective metric. Dark matter couples to an Einstein-frame metric, and experiences a matter-dominated, decelerating cosmology up to the present time. Ordinary matter couples to an effective metric that depends also on the DM density, in such a way that it experiences late-time acceleration. Linear density perturbations are stable and propagate with arbitrarily small sound speed, at least in the case of "pressure" coupling. Assuming a simple parametrization of the effective metric, we show that our model can successfully match a set of basic cosmological observables, including luminosity distance, baryon acoustic oscillation measurements, angular-diameter distance to last scattering, etc. For the growth history of density perturbations, we find an intriguing connection between the growth factor and the Hubble constant. To get a growth history similar to the Λ CDM prediction, our model predicts a higher H0, closer to the value preferred by direct estimates. On the flip side, we tend to overpredict the growth of structures whenever H0 is comparable to the Planck preferred value. The model also tends to predict larger redshift-space distortions at low redshift than Λ CDM .

Global constraints on vector-like WIMP effective interactions

DOE PAGES

Blennow, Mattias; Coloma, Pilar; Fernandez-Martinez, Enrique; ...

2016-04-07

In this work we combine information from relic abundance, direct detection, cosmic microwave background, positron fraction, gamma rays, and colliders to explore the existing constraints on couplings between Dark Matter and Standard Model constituents when no underlying model or correlation is assumed. For definiteness, we include independent vector-like effective interactions for each Standard Model fermion. Our results show that low Dark Matter masses below 20 GeV are disfavoured at the 3 σ  level with respect to higher masses, due to the tension between the relic abundance requirement and upper constraints on the Dark Matter couplings. Lastly, large couplings are typically onlymore » allowed in combinations which avoid effective couplings to the nuclei used in direct detection experiments.« less

On the dual equivalence of the self-dual and topologically massive /B∧F models coupled to dynamical fermionic matter

NASA Astrophysics Data System (ADS)

Menezes, R.; Nascimento, J. R. S.; Ribeiro, R. F.; Wotzasek, C.

2002-06-01

We study the equivalence between the /B∧F self-dual (SDB∧F) and the /B∧F topologically massive (TMB∧F) models including the coupling to dynamical, U(1) charged fermionic matter. This is done through an iterative procedure of gauge embedding that produces the dual mapping. In the interactive cases, the minimal coupling adopted for both vector and tensor fields in the self-dual representation is transformed into a non-minimal magnetic like coupling in the topologically massive representation but with the currents swapped. It is known that to establish this equivalence a current-current interaction term is needed to render the matter sector unchanged. We show that both terms arise naturally from the embedding procedure.

New LUX result constrains exotic quark mediators with the vector dark matter

NASA Astrophysics Data System (ADS)

Chen, Chuan-Ren; Li, Ming-Jie

2016-12-01

The scenario of the compressed mass spectrum between heavy quark and dark matter is a challenge for LHC searches. However, the elastic scattering cross-section between dark matter and nuclei in dark matter direct detection experiments can be enhanced with nearly degenerate masses between heavy quarks and dark matter. In this paper, we illustrate such scenario with a vector dark matter, using the latest result from LUX 2016. The mass constraints on heavy quarks can be more stringent than current limits from LHC, unless the coupling strength is very small. However, the compress mass spectrum with allowed tiny coupling strength makes the decay lifetime of heavy quarks longer than the timescale of QCD hadronization.

Butt-coupled interface between stoichiometric Si3N4 and thin-film plasmonic waveguides

NASA Astrophysics Data System (ADS)

Dabos, G.; Ketzaki, D.; Tsiokos, D.; Pleros, N.

2017-02-01

Plasmonic technology has emerged as the most promising candidate to revolutionize future photonic-integrated-circuits (PICs) and deliver performance breakthroughs in diverse application areas by providing increased light-matter interaction at the nanometer scale, overcoming the diffraction limit. However, high insertion losses of plasmonic devices impede their practical deployment in PICs. To overcome this hurdle, selective integration of individual plasmonic devices on low-loss photonic platforms is considered, allowing for enhanced chip-scale functionalities with realistic power budgets. In this context, highly-efficient and fabrication-tolerant optical interfaces for co-planar plasmonic and photonic waveguides become essential, bridging these two "worlds" and ease combined high-volume manufacturing. Herein, a TM-mode butt-coupled interface for stoichiometric Si3N4 and Au-based thin-film plasmonic waveguides is proposed aiming to be utilized for bio-sensing applications. Following a systematic design process, this new configuration has been analyzed through 3D FDTD numerical simulations demonstrating coupling efficiencies up to 64% at the wavelength of 1.55 μm, with increased fabrication tolerance compared to silicon based waveguide alternatives.

Insight into photocatalytic degradation of dissolved organic matter in UVA/TiO₂ systems revealed by fluorescence EEM-PARAFAC.

PubMed

Phong, Diep Dinh; Hur, Jin

2015-12-15

Photocatalytic degradation of dissolved organic matter (DOM) using TiO2 as a catalyst and UVA as a light source was examined under various experimental settings with different TiO2 doses, solution pH, and the light intensities. The changes in UV absorbance and fluorescence with the irradiation time followed a pseudo-first order model much better than those of dissolved organic carbon. In general, the degradation rates were increased by higher TiO2 doses and light intensities. However, the exact photocatalytic responses of DOM to the irradiation were affected by many other factors such as aggregation of TiO2, light scattering, hydroxyl radicals produced, and DOM sorption on TiO2. Fluorescence excitation-emission matrix (EEM) coupled with parallel factor analysis (PARAFAC) revealed that the DOM changes in fluorescence could be described by the combinations of four dissimilar components including one protein-like, two humic-like, and one terrestrial humic-like components, each of which followed well the pseudo-first order model. The photocatalytic degradation rates were higher for protein-like versus humic-like component, whereas the opposite order was displayed for the degradation rates in the absence of TiO2, suggesting different dominant mechanisms operating between the systems with and without TiO2. Our results based on EEM-PARAFAC provided new insights into the underlying mechanisms associated with the photocatalytic degradation of DOM as well as the potential environmental impact of the treated water. This study demonstrated a successful application of EEM-PARAFAC for photocatalytic systems via directly comparing the kinetic rates of the individual DOM components with different compositions. Copyright © 2015 Elsevier Ltd. All rights reserved.

High-energy neutrinos from multibody decaying dark matter

NASA Astrophysics Data System (ADS)

Hiroshima, Nagisa; Kitano, Ryuichiro; Kohri, Kazunori; Murase, Kohta

2018-01-01

Since the report of the PeV-TeV neutrinos by the IceCube Collaboration, various particle physics models have been proposed to explain the neutrino spectrum by dark matter particles decaying into neutrinos and other standard model particles. In such scenarios, simultaneous γ -ray emission is commonly expected. Therefore, multimessenger connections are generally important for the indirect searches of dark matters. The recent development of γ -ray astronomy puts stringent constraints on the properties of dark matter, especially by observations with the Fermi γ -ray satellite in the last several years. Motivated by the lack of γ -ray as well as the shape of the neutrino spectrum observed by IceCube, we discuss a scenario in which the DM is a PeV scale particle which couples strongly to other invisible particles and its decay products do not contain a charged particle. As an example to realize such possibilities, we consider a model of fermionic dark matter that decays into a neutrino and many invisible fermions. The dark matter decay is secluded in the sense that the emitted products are mostly neutrinos and dark fermions. One remarkable feature of this model is the resulting broadband neutrino spectra around the energy scale of the dark matter. We apply this model to multi-PeV dark matter, and discuss possible observable consequences in light of the IceCube data. In particular, this model could account for the large flux at medium energies of ˜10 - 100 TeV , possibly as well as the second peak at PeV, without violating the stringent γ -ray constraints from Fermi and air-shower experiments such as CASA-MIA.

Calculation of momentum distribution function of a non-thermal fermionic dark matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biswas, Anirban; Gupta, Aritra, E-mail: anirbanbiswas@hri.res.in, E-mail: aritra@hri.res.in

The most widely studied scenario in dark matter phenomenology is the thermal WIMP scenario. Inspite of numerous efforts to detect WIMP, till now we have no direct evidence for it. A possible explanation for this non-observation of dark matter could be because of its very feeble interaction strength and hence, failing to thermalise with the rest of the cosmic soup. In other words, the dark matter might be of non-thermal origin where the relic density is obtained by the so-called freeze-in mechanism. Furthermore, if this non-thermal dark matter is itself produced substantially from the decay of another non-thermal mother particle,more » then their distribution functions may differ in both size and shape from the usual equilibrium distribution function. In this work, we have studied such a non-thermal (fermionic) dark matter scenario in the light of a new type of U(1){sub B−L} model. The U(1){sub B−L} model is interesting, since, besides being anomaly free, it can give rise to neutrino mass by Type II see-saw mechanism. Moreover, as we will show, it can accommodate a non-thermal fermionic dark matter as well. Starting from the collision terms, we have calculated the momentum distribution function for the dark matter by solving a coupled system of Boltzmann equations. We then used it to calculate the final relic abundance, as well as other relevant physical quantities. We have also compared our result with that obtained from solving the usual Boltzmann (or rate) equations directly in terms of comoving number density, Y . Our findings suggest that the latter approximation is valid only in cases where the system under study is close to equilibrium, and hence should be used with caution.« less

Calculation of momentum distribution function of a non-thermal fermionic dark matter

NASA Astrophysics Data System (ADS)

Biswas, Anirban; Gupta, Aritra

2017-03-01

The most widely studied scenario in dark matter phenomenology is the thermal WIMP scenario. Inspite of numerous efforts to detect WIMP, till now we have no direct evidence for it. A possible explanation for this non-observation of dark matter could be because of its very feeble interaction strength and hence, failing to thermalise with the rest of the cosmic soup. In other words, the dark matter might be of non-thermal origin where the relic density is obtained by the so-called freeze-in mechanism. Furthermore, if this non-thermal dark matter is itself produced substantially from the decay of another non-thermal mother particle, then their distribution functions may differ in both size and shape from the usual equilibrium distribution function. In this work, we have studied such a non-thermal (fermionic) dark matter scenario in the light of a new type of U(1)B-L model. The U(1)B-L model is interesting, since, besides being anomaly free, it can give rise to neutrino mass by Type II see-saw mechanism. Moreover, as we will show, it can accommodate a non-thermal fermionic dark matter as well. Starting from the collision terms, we have calculated the momentum distribution function for the dark matter by solving a coupled system of Boltzmann equations. We then used it to calculate the final relic abundance, as well as other relevant physical quantities. We have also compared our result with that obtained from solving the usual Boltzmann (or rate) equations directly in terms of comoving number density, Y. Our findings suggest that the latter approximation is valid only in cases where the system under study is close to equilibrium, and hence should be used with caution.

Ultrastrong Carbon Thin Films from Diamond to Graphene under Extreme Conditions: Probing Atomic Scale Interfacial Mechanisms to Achieve Ultralow Friction and Wear

DTIC Science & Technology

2016-12-08

of Current Advances and Challenges for the Future. Trib. Int. 37, 517-536 (2004). 6. Doll, G.L. and Evans, R.D. Solving Wind Turbine Tribological...and Doll, G.L. Tribological Advancements for Reliable Wind Turbine Performance. Phil. Trans. A 368, 4829-50 (2010). 8. Grillo, S.E. and Field, J.E...environments (as found in the upper atmosphere and in outer space), and protective coatings for bearings, bushings, and gears in engines, turbines and

Redox Modulation of Flavin and Tyrosine Determines Photoinduced Proton-coupled Electron Transfer and Photoactivation of BLUF Photoreceptors

PubMed Central

Mathes, Tilo; van Stokkum, Ivo H. M.; Stierl, Manuela; Kennis, John T. M.

2012-01-01

Photoinduced electron transfer in biological systems, especially in proteins, is a highly intriguing matter. Its mechanistic details cannot be addressed by structural data obtained by crystallography alone because this provides only static information on a given redox system. In combination with transient spectroscopy and site-directed manipulation of the protein, however, a dynamic molecular picture of the ET process may be obtained. In BLUF (blue light sensors using FAD) photoreceptors, proton-coupled electron transfer between a tyrosine and the flavin cofactor is the key reaction to switch from a dark-adapted to a light-adapted state, which corresponds to the biological signaling state. Particularly puzzling is the fact that, although the various naturally occurring BLUF domains show little difference in the amino acid composition of the flavin binding pocket, the reaction rates of the forward reaction differ quite largely from a few ps up to several hundred ps. In this study, we modified the redox potential of the flavin/tyrosine redox pair by site-directed mutagenesis close to the flavin C2 carbonyl and fluorination of the tyrosine, respectively. We provide information on how changes in the redox potential of either reaction partner significantly influence photoinduced proton-coupled electron transfer. The altered redox potentials allowed us furthermore to experimentally describe an excited state charge transfer intermediately prior to electron transfer in the BLUF photocycle. Additionally, we show that the electron transfer rate directly correlates with the quantum yield of signaling state formation. PMID:22833672

Quantum Control of Light and Matter: From the Macroscopic to the Nano Scale

DTIC Science & Technology

2016-02-02

navigation, and hybrid bio -graphene devices, incorporating enzymes positioned on graphene, for light-driven bio -fuel production with controlled...enzymatic rates. 15. SUBJECT TERMS Light-matter interactions; Quantum control; Slow light; Bose-Einstein condensates; Nano-science; Hybrid bio -nano...precise navigation. They also include hybrid bio -graphene devices incorporating enzymes positioned on graphene for dynamic control of enzymatic

Constrained exceptional supersymmetric standard model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Athron, P.; King, S. F.; Miller, D. J.

2009-08-01

We propose and study a constrained version of the exceptional supersymmetric standard model (E{sub 6}SSM), which we call the cE{sub 6}SSM, based on a universal high energy scalar mass m{sub 0}, trilinear scalar coupling A{sub 0} and gaugino mass M{sub 1/2}. We derive the renormalization group (RG) Equations for the cE{sub 6}SSM, including the extra U(1){sub N} gauge factor and the low-energy matter content involving three 27 representations of E{sub 6}. We perform a numerical RG analysis for the cE{sub 6}SSM, imposing the usual low-energy experimental constraints and successful electroweak symmetry breaking. Our analysis reveals that the sparticle spectrum ofmore » the cE{sub 6}SSM involves a light gluino, two light neutralinos, and a light chargino. Furthermore, although the squarks, sleptons, and Z{sup '} boson are typically heavy, the exotic quarks and squarks can also be relatively light. We finally specify a set of benchmark points, which correspond to particle spectra, production modes, and decay patterns peculiar to the cE{sub 6}SSM, altogether leading to spectacular new physics signals at the Large Hadron Collider.« less

The vacuole model: new terms in the second order deflection of light

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhattacharya, Amrita; Nandi, Kamal K.; Garipova, Guzel M.

2011-02-01

The present paper is an extension of a recent work (Bhattacharya et al. 2010) to the Einstein-Strauss vacuole model with a cosmological constant, where we work out the light deflection by considering perturbations up to order M{sup 3} and confirm the light bending obtained previously in their vacuole model by Ishak et al. (2008). We also obtain another local coupling term −5πM{sup 2}Λ/8 related to Λ, in addition to the one obtained by Sereno (2008, 2009). We argue that the vacuole method for light deflection is exclusively suited to cases where the cosmological constant Λ disappears from the path equation.more » However, the original Rindler-Ishak method (2007) still applies even if a certain parameter γ of Weyl gravity does not disappear. Here, using an alternative prescription, we obtain the known term −γR/2, as well as another new local term 3πγM/2 between M and γ. Physical implications are compared, where we argue that the repulsive term −γR/2 can be masked by the Schwarzschild term 2M/R in the halo regime supporting attractive property of the dark matter.« less

Contribution of Lubricating Oil to Particulate Matter Emissions from Light-Duty Gasoline Vehicles in Kansas City

EPA Science Inventory

The contribution of lubricating oil to particulate matter (PM) emissions representative of the in-use 2004 light-duty gasoline vehicles fleet is estimated from the Kansas City Light-Duty Vehicle Emissions Study (KCVES). PM emissions are apportioned to lubricating oil and gasoline...

Contribution of Lubricating Oil to Particulate Matter Emissions from Light-duty Gasoline Vehicles in Kansas City

EPA Science Inventory

The contribution of lubricating oil to particulate matter (PM) emissions representative of the in-use 2004 light-duty gasoline vehicles fleet is estimated from the Kansas City Light-Duty Vehicle Emissions Study (KCVES). PM emissions are apportioned to lubricating oil and gasoline...

Dipolar dark matter with massive bigravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blanchet, Luc; Heisenberg, Lavinia; Department of Physics & The Oskar Klein Centre, AlbaNova University Centre,Roslagstullsbacken 21, 10691 Stockholm

2015-12-14

Massive gravity theories have been developed as viable IR modifications of gravity motivated by dark energy and the problem of the cosmological constant. On the other hand, modified gravity and modified dark matter theories were developed with the aim of solving the problems of standard cold dark matter at galactic scales. Here we propose to adapt the framework of ghost-free massive bigravity theories to reformulate the problem of dark matter at galactic scales. We investigate a promising alternative to dark matter called dipolar dark matter (DDM) in which two different species of dark matter are separately coupled to the twomore » metrics of bigravity and are linked together by an internal vector field. We show that this model successfully reproduces the phenomenology of dark matter at galactic scales (i.e. MOND) as a result of a mechanism of gravitational polarisation. The model is safe in the gravitational sector, but because of the particular couplings of the matter fields and vector field to the metrics, a ghost in the decoupling limit is present in the dark matter sector. However, it might be possible to push the mass of the ghost beyond the strong coupling scale by an appropriate choice of the parameters of the model. Crucial questions to address in future work are the exact mass of the ghost, and the cosmological implications of the model.« less

Dipolar dark matter with massive bigravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blanchet, Luc; Heisenberg, Lavinia, E-mail: blanchet@iap.fr, E-mail: laviniah@kth.se

2015-12-01

Massive gravity theories have been developed as viable IR modifications of gravity motivated by dark energy and the problem of the cosmological constant. On the other hand, modified gravity and modified dark matter theories were developed with the aim of solving the problems of standard cold dark matter at galactic scales. Here we propose to adapt the framework of ghost-free massive bigravity theories to reformulate the problem of dark matter at galactic scales. We investigate a promising alternative to dark matter called dipolar dark matter (DDM) in which two different species of dark matter are separately coupled to the twomore » metrics of bigravity and are linked together by an internal vector field. We show that this model successfully reproduces the phenomenology of dark matter at galactic scales (i.e. MOND) as a result of a mechanism of gravitational polarisation. The model is safe in the gravitational sector, but because of the particular couplings of the matter fields and vector field to the metrics, a ghost in the decoupling limit is present in the dark matter sector. However, it might be possible to push the mass of the ghost beyond the strong coupling scale by an appropriate choice of the parameters of the model. Crucial questions to address in future work are the exact mass of the ghost, and the cosmological implications of the model.« less

The Janus Cosmological Model (JCM) : An answer to the missing cosmological antimatter

NASA Astrophysics Data System (ADS)

D'Agostini, Gilles; Petit, Jean-Pierre

2017-01-01

Cosmological antimatter absence remains unexplained. Twin universes 1967 Sakarov's model suggests an answer: excess of matter and anti-quarks production in our universe is balanced by equivalent excess of antimatter and quark in twin universe. JCM provides geometrical framework, with a single manifold , two metrics solutions of two coupled field equations, to describe two populations of particles, one with positive energy-mass and the other with negative energy-mass : the `twin matter'. In a quantum point of view, it's a copy of the standard matter but with negative mass and energy. The matter-antimatter duality holds in both sectors. The standard and twin matters do not interact except through the gravitational coupling expressed in field equations. The twin matter is unobservable from matter-made apparatus. Field equations shows that matter and twin matter repel each other. Twin matter surrounding galaxies explains their confinement (dark matter role) and, in the dust universe era, mainly drives the process of expansion of the positive sector, responsible of the observed acceleration (dark energy role).

A search for a new gauge boson A'

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jensen, Eric L.

2013-08-01

In the Standard Model, gauge bosons mediate the strong, weak, and electromagnetic forces. New forces could have escaped detection only if their mediators are either heavier than order(TeV) or weakly coupled to charged matter. New vector bosons with small coupling {alpha}' arise naturally from a small kinetic mixing with the photon and have received considerable attention as an explanation of various dark matter related anomalies. Such particles can be produced in electron-nucleus fixed-target scattering and then decay to e +e -+ pairs. New light vector bosons and their associated forces are a common feature of Standard Model extensions, but existingmore » constraints are remarkably sparse. The APEX experiment will search for a new vector boson A' with coupling α'/α fs > 6 × 10 -8 to electrons in the mass range 65MeV < mass A' < 550MeV. The experiment will study e +e - production off an electron beam incident on a high-Z target in Hall A at Jefferson Lab. The e - and e + will be detected in the High Resolution Spectrometers (HRSs). The invariant mass spectrum of the e +e - pairs will be scanned for a narrow resonance corresponding to the mass of the A'. A test run for the APEX experiment was held in the summer of 2010. Using the test run data, an A' search was performed in the mass range 175-250 MeV. The search found no evidence for an A' → e +e -reaction, and set an upper limit of {alpha}'/{alpha}{sub fs} ~ 10 -6.« less

Electromagnetically induced transparency and nonlinear pulse propagation in a combined tripod and Λ atom-light coupling scheme

NASA Astrophysics Data System (ADS)

Hamedi, H. R.; Ruseckas, J.; Juzeliūnas, G.

2017-09-01

We consider propagation of a probe pulse in an atomic medium characterized by a combined tripod and Lambda (Λ) atom-light coupling scheme. The scheme involves three atomic ground states coupled to two excited states by five light fields. It is demonstrated that dark states can be formed for such an atom-light coupling. This is essential for formation of the electromagnetically induced transparency (EIT) and slow light. In the limiting cases the scheme reduces to conventional Λ- or N-type atom-light couplings providing the EIT or absorption, respectively. Thus, the atomic system can experience a transition from the EIT to the absorption by changing the amplitudes or phases of control lasers. Subsequently the scheme is employed to analyze the nonlinear pulse propagation using the coupled Maxwell-Bloch equations. It is shown that a generation of stable slow light optical solitons is possible in such a five-level combined tripod and Λ atomic system.

Sideband cooling of micromechanical motion to the quantum ground state.

PubMed

Teufel, J D; Donner, T; Li, Dale; Harlow, J W; Allman, M S; Cicak, K; Sirois, A J; Whittaker, J D; Lehnert, K W; Simmonds, R W

2011-07-06

The advent of laser cooling techniques revolutionized the study of many atomic-scale systems, fuelling progress towards quantum computing with trapped ions and generating new states of matter with Bose-Einstein condensates. Analogous cooling techniques can provide a general and flexible method of preparing macroscopic objects in their motional ground state. Cavity optomechanical or electromechanical systems achieve sideband cooling through the strong interaction between light and motion. However, entering the quantum regime--in which a system has less than a single quantum of motion--has been difficult because sideband cooling has not sufficiently overwhelmed the coupling of low-frequency mechanical systems to their hot environments. Here we demonstrate sideband cooling of an approximately 10-MHz micromechanical oscillator to the quantum ground state. This achievement required a large electromechanical interaction, which was obtained by embedding a micromechanical membrane into a superconducting microwave resonant circuit. To verify the cooling of the membrane motion to a phonon occupation of 0.34 ± 0.05 phonons, we perform a near-Heisenberg-limited position measurement within (5.1 ± 0.4)h/2π, where h is Planck's constant. Furthermore, our device exhibits strong coupling, allowing coherent exchange of microwave photons and mechanical phonons. Simultaneously achieving strong coupling, ground state preparation and efficient measurement sets the stage for rapid advances in the control and detection of non-classical states of motion, possibly even testing quantum theory itself in the unexplored region of larger size and mass. Because mechanical oscillators can couple to light of any frequency, they could also serve as a unique intermediary for transferring quantum information between microwave and optical domains.

Mass scale of vectorlike matter and superpartners from IR fixed point predictions of gauge and top Yukawa couplings

NASA Astrophysics Data System (ADS)

Dermíšek, Radovan; McGinnis, Navin

2018-03-01

We use the IR fixed point predictions for gauge couplings and the top Yukawa coupling in the minimal supersymmetric model (MSSM) extended with vectorlike families to infer the scale of vectorlike matter and superpartners. We quote results for several extensions of the MSSM and present results in detail for the MSSM extended with one complete vectorlike family. We find that for a unified gauge coupling αG>0.3 vectorlike matter or superpartners are expected within 1.7 TeV (2.5 TeV) based on all three gauge couplings being simultaneously within 1.5% (5%) from observed values. This range extends to about 4 TeV for αG>0.2 . We also find that in the scenario with two additional large Yukawa couplings of vectorlike quarks the IR fixed point value of the top Yukawa coupling independently points to a multi-TeV range for vectorlike matter and superpartners. Assuming a universal value for all large Yukawa couplings at the grand unified theory scale, the measured top quark mass can be obtained from the IR fixed point for tan β ≃4 . The range expands to any tan β >3 for significant departures from the universality assumption. Considering that the Higgs boson mass also points to a multi-TeV range for superpartners in the MSSM, adding a complete vectorlike family at the same scale provides a compelling scenario where the values of gauge couplings and the top quark mass are understood as a consequence of the particle content of the model.

Gravitational waves in theories with a non-minimal curvature-matter coupling

NASA Astrophysics Data System (ADS)

Bertolami, Orfeu; Gomes, Cláudio; Lobo, Francisco S. N.

2018-04-01

Gravitational waves in the presence of a non-minimal curvature-matter coupling are analysed, both in the Newman-Penrose and perturbation theory formalisms. Considering a cosmological constant as a source, the non-minimally coupled matter-curvature model reduces to f( R) theories. This is in good agreement with the most recent data. Furthermore, a dark energy-like fluid is briefly considered, where the propagation equation for the tensor modes differs from the previous scenario, in that the scalar mode equation has an extra term, which can be interpreted as the longitudinal mode being the result of the mixture of two fundamental excitations δ R and δ ρ.

Severely Constraining Dark Matter Interpretations of the 21-cm Anomaly

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berlin, Asher; Hooper, Dan; Krnjaic, Gordan

The EDGES Collaboration has recently reported the detection of a stronger-than-expected absorption feature in the global 21-cm spectrum, centered at a frequency corresponding to a redshift of z ~ 17. This observation has been interpreted as evidence that the gas was cooled during this era as a result of scattering with dark matter. In this study, we explore this possibility, applying constraints from the cosmic microwave background, light element abundances, Supernova 1987A, and a variety of laboratory experiments. After taking these constraints into account, we find that the vast majority of the parameter space capable of generating the observed 21-cmmore » signal is ruled out. The only range of models that remains viable is that in which a small fraction, ~ 0.3-2%, of the dark matter consists of particles with a mass of ~ 10-80 MeV and which couple to the photon through a small electric charge, epsilon ~ 10^{-6}-10^{-4}. Furthermore, in order to avoid being overproduced in the early universe, such models must be supplemented with an additional depletion mechanism, such as annihilations through a L_{\\mu}-L_{\\tau} gauge boson or annihilations to a pair of rapidly decaying hidden sector scalars.« less

Chiral Dark Sector

NASA Astrophysics Data System (ADS)

Co, Raymond T.; Harigaya, Keisuke; Nomura, Yasunori

2017-03-01

We present a simple and natural dark sector model in which dark matter particles arise as composite states of hidden strong dynamics and their stability is ensured by accidental symmetries. The model has only a few free parameters. In particular, the gauge symmetry of the model forbids the masses of dark quarks, and the confinement scale of the dynamics provides the unique mass scale of the model. The gauge group contains an Abelian symmetry U (1 )D , which couples the dark and standard model sectors through kinetic mixing. This model, despite its simple structure, has rich and distinctive phenomenology. In the case where the dark pion becomes massive due to U (1 )D quantum corrections, direct and indirect detection experiments can probe thermal relic dark matter which is generically a mixture of the dark pion and the dark baryon, and the Large Hadron Collider can discover the U (1 )D gauge boson. Alternatively, if the dark pion stays light due to a specific U (1 )D charge assignment of the dark quarks, then the dark pion constitutes dark radiation. The signal of this radiation is highly correlated with that of dark baryons in dark matter direct detection.

Chiral Dark Sector.

PubMed

Co, Raymond T; Harigaya, Keisuke; Nomura, Yasunori

2017-03-10

We present a simple and natural dark sector model in which dark matter particles arise as composite states of hidden strong dynamics and their stability is ensured by accidental symmetries. The model has only a few free parameters. In particular, the gauge symmetry of the model forbids the masses of dark quarks, and the confinement scale of the dynamics provides the unique mass scale of the model. The gauge group contains an Abelian symmetry U(1)_{D}, which couples the dark and standard model sectors through kinetic mixing. This model, despite its simple structure, has rich and distinctive phenomenology. In the case where the dark pion becomes massive due to U(1)_{D} quantum corrections, direct and indirect detection experiments can probe thermal relic dark matter which is generically a mixture of the dark pion and the dark baryon, and the Large Hadron Collider can discover the U(1)_{D} gauge boson. Alternatively, if the dark pion stays light due to a specific U(1)_{D} charge assignment of the dark quarks, then the dark pion constitutes dark radiation. The signal of this radiation is highly correlated with that of dark baryons in dark matter direct detection.

Limits on light WIMPs with a 1 kg-scale germanium detector at 160 eVee physics threshold at the China Jinping Underground Laboratory

NASA Astrophysics Data System (ADS)

Yang, Li-Tao; Li, Hau-Bin; Yue, Qian; Kang, Ke-Jun; Cheng, Jian-Ping; Li, Yuan-Jing; Tsz-King Wong, Henry; Aǧartioǧlu, M.; An, Hai-Peng; Chang, Jian-Ping; Chen, Jing-Han; Chen, Yun-Hua; Deng, Zhi; Du, Qiang; Gong, Hui; He, Li; Hu, Jin-Wei; Hu, Qing-Dong; Huang, Han-Xiong; Jia, Li-Ping; Jiang, Hao; Li, Hong; Li, Jian-Min; Li, Jin; Li, Xia; Li, Xue-Qian; Li, Yu-Lan; Lin, Fong-Kay; Lin, Shin-Ted; Liu, Shu-Kui; Liu, Zhong-Zhi; Ma, Hao; Ma, Jing-Lu; Pan, Hui; Ren, Jie; Ruan, Xi-Chao; Sevda, B.; Sharma, Vivek; Shen, Man-Bin; Singh, Lakhwinder; Singh, Manoj Kumar; Tang, Chang-Jian; Tang, Wei-You; Tian, Yang; Wang, Ji-Min; Wang, Li; Wang, Qing; Wang, Yi; Wu, Shi-Yong; Wu, Yu-Cheng; Xing, Hao-Yang; Xu, Yin; Xue, Tao; Yang, Song-Wei; Yi, Nan; Yu, Chun-Xu; Yu, Hai-Jun; Yue, Jian-Feng; Zeng, Xiong-Hui; Zeng, Ming; Zeng, Zhi; Zhang, Yun-Hua; Zhao, Ming-Gang; Zhao, Wei; Zhou, Ji-Fang; Zhou, Zu-Ying; Zhu, Jing-Jun; Zhu, Zhong-Hua; CDEX Collaboration

2018-01-01

We report results of a search for light weakly interacting massive particle (WIMP) dark matter from the CDEX-1 experiment at the China Jinping Underground Laboratory (CJPL). Constraints on WIMP-nucleon spin-independent (SI) and spin-dependent (SD) couplings are derived with a physics threshold of 160 eVee, from an exposure of 737.1 kg-days. The SI and SD limits extend the lower reach of light WIMPs to 2 GeV and improve over our earlier bounds at WIMP mass less than 6 GeV. Supported by the National Key Research and Development Program of China (2017YFA0402200, 2017YFA0402201), the National Natural Science Foundation of China (11175099, 11275107, 11475117, 11475099, 11475092, 11675088), the National Basic Research Program of China (973 Program) (2010CB833006). We thank the support of grants from the Tsinghua University Initiative Scientific Research Program (20121088494, 20151080354) and the Academia Sinica Investigator Award 2011-15, contracts 103-2112-M-001-024 and 104-2112-M-001-038-MY3 from the Ministry of Science and Technology of Taiwan.

Asymptotic safety of higher derivative quantum gravity non-minimally coupled with a matter system

NASA Astrophysics Data System (ADS)

Hamada, Yuta; Yamada, Masatoshi

2017-08-01

We study asymptotic safety of models of the higher derivative quantum gravity with and without matter. The beta functions are derived by utilizing the functional renormalization group, and non-trivial fixed points are found. It turns out that all couplings in gravity sector, namely the cosmological constant, the Newton constant, and the R 2 and R μν 2 coupling constants, are relevant in case of higher derivative pure gravity. For the Higgs-Yukawa model non-minimal coupled with higher derivative gravity, we find a stable fixed point at which the scalar-quartic and the Yukawa coupling constants become relevant. The relevant Yukawa coupling is crucial to realize the finite value of the Yukawa coupling constants in the standard model.

Terahertz Physics

NASA Astrophysics Data System (ADS)

Lewis, R. A.

2013-01-01

1. Introduction; Part I. Basics: 2. Oscillations; 3. Combining oscillations; 4. Light; 5. Matter; 6. Interaction of light and matter; Part II. Components: 7. Sources; 8. Optics; 9. Detectors; Part III. Applications: 10. Spectroscopy; 11. Imaging; Glossary; Appendices; Index.

Coupled changes in brain white matter microstructure and fluid intelligence in later life.

PubMed

Ritchie, Stuart J; Bastin, Mark E; Tucker-Drob, Elliot M; Maniega, Susana Muñoz; Engelhardt, Laura E; Cox, Simon R; Royle, Natalie A; Gow, Alan J; Corley, Janie; Pattie, Alison; Taylor, Adele M; Valdés Hernández, Maria Del C; Starr, John M; Wardlaw, Joanna M; Deary, Ian J

2015-06-03

Understanding aging-related cognitive decline is of growing importance in aging societies, but relatively little is known about its neural substrates. Measures of white matter microstructure are known to correlate cross-sectionally with cognitive ability measures, but only a few small studies have tested for longitudinal relations among these variables. We tested whether there were coupled changes in brain white matter microstructure indexed by fractional anisotropy (FA) and three broad cognitive domains (fluid intelligence, processing speed, and memory) in a large cohort of human participants with longitudinal diffusion tensor MRI and detailed cognitive data taken at ages 73 years (n = 731) and 76 years (n = 488). Longitudinal changes in white matter microstructure were coupled with changes in fluid intelligence, but not with processing speed or memory. Individuals with higher baseline white matter FA showed less subsequent decline in processing speed. Our results provide evidence for a longitudinal link between changes in white matter microstructure and aging-related cognitive decline during the eighth decade of life. They are consistent with theoretical perspectives positing that a corticocortical "disconnection" partly explains cognitive aging. Copyright © 2015 Ritchie et al.

Plasmonic interferometers: From physics to biosensing applications

NASA Astrophysics Data System (ADS)

Zeng, Xie

Optical interferometry has a long history and wide range of applications. In recent years, plasmonic interferometer arouses great interest due to its compact size and enhanced light-matter interaction. They have demonstrated attractive applications in biomolecule sensing, optical modulation/switching, and material characterization, etc. In this work, we first propose a practical far-field method to extract the intrinsic phase dispersion, revealing important phase information during interactions among free-space light, nanostructure, and SPs. The proposed approach is confirmed by both simulation and experiment. Then we design novel plasmonic interferometer structure for sensitive optical sensing applications. To overcome two major limitations suffered by previously reported double-slit plasmonic Mach-Zehnder interferometer (PMZI), two new schemes are proposed and investigated. (1) A PMZI based on end-fire coupling improves the SP coupling efficiency and enhance the interference contrast more than 50 times. (2) In another design, a multi-layered metal-insulator-metal PMZI releases the requirement for single-slit illumination, which enables sensitive, high-throughput sensing applications based on intensity modulation. We develop a sensitive, low-cost and high-throughput biosensing platform based on intensity modulation using ring-hole plasmonic interferometers. This biosensor is then integrated with cell-phone-based microscope, which is promising to develop a portable sensor for point-of-care diagnostics, epidemic disease control and food safety monitoring.

Indirect detection of neutrino portal dark matter

NASA Astrophysics Data System (ADS)

Batell, Brian; Han, Tao; Shams Es Haghi, Barmak

2018-05-01

We investigate the feasibility of the indirect detection of dark matter in a simple model using the neutrino portal. The model is very economical, with right-handed neutrinos generating neutrino masses through the type-I seesaw mechanism and simultaneously mediating interactions with dark matter. Given the small neutrino Yukawa couplings expected in a type-I seesaw, direct detection and accelerator probes of dark matter in this scenario are challenging. However, dark matter can efficiently annihilate to right-handed neutrinos, which then decay via active-sterile mixing through the weak interactions, leading to a variety of indirect astronomical signatures. We derive the existing constraints on this scenario from Planck cosmic microwave background measurements, Fermi dwarf spheroidal galaxy and Galactic center gamma-ray observations, and AMS-02 antiproton observations, and we also discuss the future prospects of Fermi and the Cherenkov Telescope Array. Thermal annihilation rates are already being probed for dark matter lighter than about 50 GeV, and this can be extended to dark matter masses of 100 GeV and beyond in the future. This scenario can also provide a dark matter interpretation of the Fermi Galactic center gamma-ray excess, and we confront this interpretation with other indirect constraints. Finally we discuss some of the exciting implications of extensions of the minimal model with large neutrino Yukawa couplings and Higgs portal couplings.

Observation of optomechanical buckling transitions

PubMed Central

Xu, H.; Kemiktarak, U.; Fan, J.; Ragole, S.; Lawall, J.; Taylor, J. M.

2017-01-01

Correlated phases of matter provide long-term stability for systems as diverse as solids, magnets and potential exotic quantum materials. Mechanical systems, such as buckling transition spring switches, can have engineered, stable configurations whose dependence on a control variable is reminiscent of non-equilibrium phase transitions. In hybrid optomechanical systems, light and matter are strongly coupled, allowing engineering of rapid changes in the force landscape, storing and processing information, and ultimately probing and controlling behaviour at the quantum level. Here we report the observation of first- and second-order buckling transitions between stable mechanical states in an optomechanical system, in which full control of the nature of the transition is obtained by means of the laser power and detuning. The underlying multiwell confining potential we create is highly tunable, with a sub-nanometre distance between potential wells. Our results enable new applications in photonics and information technology, and may enable explorations of quantum phase transitions and macroscopic quantum tunnelling in mechanical systems. PMID:28248293

Axion dark matter searches

DOE PAGES

Stern, Ian P.

2014-01-01

We report nearly all astrophysical and cosmological data point convincingly to a large component of cold dark matter in the Universe. The axion particle, first theorized as a solution to the strong charge-parity problem of quantum chromodynamics, has been established as a prominent CDM candidate. Cosmic observation and particle physics experiments have bracketed the unknown mass of the axion between approximately a μeV and a meV. The Axion Dark Matter eXperiement (ADMX) has successfully completed searches between 1.9 and 3.7 μeV down to the KSVZ photon-coupling limit. ADMX and the Axion Dark Matter eXperiement High-Frequency (ADMX-HF) will search for axionsmore » at weaker coupling and/or higher frequencies within the next few years. Status of the experiments, current research and development, and projected mass-coupling exclusion limits are presented.« less

Dark catalysis

NASA Astrophysics Data System (ADS)

Agrawal, Prateek; Cyr-Racine, Francis-Yan; Randall, Lisa; Scholtz, Jakub

2017-08-01

Recently it was shown that dark matter with mass of order the weak scale can be charged under a new long-range force, decoupled from the Standard Model, with only weak constraints from early Universe cosmology. Here we consider the implications of an additional charged particle C that is light enough to lead to significant dissipative dynamics on galactic times scales. We highlight several novel features of this model, which can be relevant even when the C particle constitutes only a small fraction of the number density (and energy density). We assume a small asymmetric abundance of the C particle whose charge is compensated by a heavy X particle so that the relic abundance of dark matter consists mostly of symmetric X and bar X, with a small asymmetric component made up of X and C. As the universe cools, it undergoes asymmetric recombination binding the free Cs into (XC) dark atoms efficiently. Even with a tiny asymmetric component, the presence of C particles catalyzes tight coupling between the heavy dark matter X and the dark photon plasma that can lead to a significant suppression of the matter power spectrum on small scales and lead to some of the strongest bounds on such dark matter theories. We find a viable parameter space where structure formation constraints are satisfied and significant dissipative dynamics can occur in galactic haloes but show a large region is excluded. Our model shows that subdominant components in the dark sector can dramatically affect structure formation.

Dark catalysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agrawal, Prateek; Cyr-Racine, Francis-Yan; Randall, Lisa

Recently it was shown that dark matter with mass of order the weak scale can be charged under a new long-range force, decoupled from the Standard Model, with only weak constraints from early Universe cosmology. Here we consider the implications of an additional charged particle C that is light enough to lead to significant dissipative dynamics on galactic times scales. We highlight several novel features of this model, which can be relevant even when the C particle constitutes only a small fraction of the number density (and energy density). We assume a small asymmetric abundance of the C particle whosemore » charge is compensated by a heavy X particle so that the relic abundance of dark matter consists mostly of symmetric X and X-bar , with a small asymmetric component made up of X and C . As the universe cools, it undergoes asymmetric recombination binding the free C s into ( XC ) dark atoms efficiently. Even with a tiny asymmetric component, the presence of C particles catalyzes tight coupling between the heavy dark matter X and the dark photon plasma that can lead to a significant suppression of the matter power spectrum on small scales and lead to some of the strongest bounds on such dark matter theories. We find a viable parameter space where structure formation constraints are satisfied and significant dissipative dynamics can occur in galactic haloes but show a large region is excluded. Our model shows that subdominant components in the dark sector can dramatically affect structure formation.« less

Benthic Marine Cyanobacterial Mat Ecosystems: Biogeochemistry and Biomarkers

NASA Technical Reports Server (NTRS)

DesMarais, David J.; DeVincenzi, Donald (Technical Monitor)

2001-01-01

Cyanobacterial mats are complete ecosystems that can include processes of primary production, diagenesis and lithification. Light sustains oxygenic photosynthesis, which in turn provides energy, organic matter and oxygen to the community. Due to both absorption and scattering phenomena, incident light is transformed with depth in the mat, both in intensity and spectral composition. Mobile photo synthesizers optimize their position with respect to this light gradient. When photosynthesis ceases at night, the upper layers of the mat become reduced and sulfidic. Counteracting gradients of oxygen and sulfide combine to provide daily-contrasting environments separated on a scale of a few mm. The functional complexity of mats, coupled with the highly proximal and ordered spatial arrangement of biota, offers the potential for a staggering number of interactions. At a minimum, the products of each functional group of microorganisms affect the other groups both positively and negatively. For example, cyanobacteria generate organic matter (potential substrates) but also oxygen (a toxin for many anaerobes). Anaerobic activity recycles nutrients to the photosynthesizers but also generates potentially toxic sulfide. The combination of benefits and hazards of light, oxygen and sulfide promotes the allocation of the various essential mat processes between light and dark periods, and to various depths in the mat. Observations of mats have produced numerous surprises. For example, obligately anaerobic processes can occur in the presence of abundant oxygen, highly reduced gases are produced in the presence of abundant sulfate, meiofauna thrive at high sulfide concentrations, and the mats' constituent populations respond to environmental changes in complex ways. While photosynthetic bacteria dominate the biomass and productivity of the mat, nonphotosynthetic, anaerobic processes constitute the ultimate biological filter on the ecosystem's emergent biosignatures, including those sedimentary textures, organic compounds, and minerals that enter the fossil record. The ability of cyanobacterial mats to channel abundant solar energy into the creation and maintenance of complex structures and processes has created a multitude of consequences, both for sedimentation and for the early evolution of our biosphere.

Weak mixing below the weak scale in dark-matter direct detection

NASA Astrophysics Data System (ADS)

Brod, Joachim; Grinstein, Benjamin; Stamou, Emmanuel; Zupan, Jure

2018-02-01

If dark matter couples predominantly to the axial-vector currents with heavy quarks, the leading contribution to dark-matter scattering on nuclei is either due to one-loop weak corrections or due to the heavy-quark axial charges of the nucleons. We calculate the effects of Higgs and weak gauge-boson exchanges for dark matter coupling to heavy-quark axial-vector currents in an effective theory below the weak scale. By explicit computation, we show that the leading-logarithmic QCD corrections are important, and thus resum them to all orders using the renormalization group.

The Exploration of Hot Nuclear Matter

NASA Astrophysics Data System (ADS)

Jacak, Barbara V.; Müller, Berndt

2012-07-01

When nuclear matter is heated beyond 2 trillion degrees, it becomes a strongly coupled plasma of quarks and gluons. Experiments using highly energetic collisions between heavy nuclei have revealed that this new state of matter is a nearly ideal, highly opaque liquid. A description based on string theory and black holes in five dimensions has made the quark-gluon plasma an archetypical strongly coupled quantum system. Open questions about the structure and theory of the quark-gluon plasma are under active investigation. Many of the insights are also relevant to ultracold fermionic atoms and strongly correlated condensed matter.

Charged composite scalar dark matter

NASA Astrophysics Data System (ADS)

Balkin, Reuven; Ruhdorfer, Maximilian; Salvioni, Ennio; Weiler, Andreas

2017-11-01

We consider a composite model where both the Higgs and a complex scalar χ, which is the dark matter (DM) candidate, arise as light pseudo Nambu-Goldstone bosons (pNGBs) from a strongly coupled sector with TeV scale confinement. The global symmetry structure is SO(7)/SO(6), and the DM is charged under an exact U(1)DM ⊂ SO(6) that ensures its stability. Depending on whether the χ shift symmetry is respected or broken by the coupling of the top quark to the strong sector, the DM can be much lighter than the Higgs or have a weak-scale mass. Here we focus primarily on the latter possibility. We introduce the lowest-lying composite resonances and impose calculability of the scalar potential via generalized Weinberg sum rules. Compared to previous analyses of pNGB DM, the computation of the relic density is improved by fully accounting for the effects of the fermionic top partners. This plays a crucial role in relaxing the tension with the current DM direct detection constraints. The spectrum of resonances contains exotic top partners charged under the U(1)DM, whose LHC phenomenology is analyzed. We identify a region of parameters with f = 1.4 TeV and 200 GeV ≲ m χ ≲ 400 GeV that satisfies all existing bounds. This DM candidate will be tested by XENON1T in the near future.

J. J. Sakurai Prize: Astrophysics, Cosmology and PQ Symmetry--Linking the Very Small and the Very Large

NASA Astrophysics Data System (ADS)

Quinn, Helen

2013-04-01

The symmetry between the laws of physics for matter and those for antimatter (technically known as CP symmetry) is broken in the weak interaction but maintained to a high level of precision in the strong interaction. In the context of the Standard Model theory of particles and their interactions this is a puzzle --what protects the strong interaction from being more ``infected'' by the lack of a symmetry of the weak interaction? I will review the history of the idea we had to solve this puzzle, its consequences, and its evolution into the versions still viable today. Our answer to this puzzle, adding a further symmetry now known as PQ symmetry, arose from thinking about the effects of quark-Higgs couplings as in the early Universe, in the phase transition that gives quarks their masses. Not only did this modification of the Standard Model arise from cosmological thinking, it turns out to have possible cosmological consequences in the form of a light, weakly-coupled particle known as the axion, a possible dark matter candidate. Furthermore astrophysical constraints on such a particle have played a role in the subsequent evolution of theories with PQ symmetry. I will review the early history of this fascinating linkage of large scale and small scale physics, leaving later developments for my collaborator and co-recipient of this prize, Roberto Peccei, to talk about.

Symmetron dark energy in laboratory experiments.

PubMed

Upadhye, Amol

2013-01-18

The symmetron scalar field is a matter-coupled dark energy candidate which effectively decouples from matter in high-density regions through a symmetry restoration. We consider a previously unexplored regime, in which the vacuum mass μ~2.4×10(-3) eV of the symmetron is near the dark energy scale, and the matter coupling parameter M~1 TeV is just beyond standard model energies. Such a field will give rise to a fifth force at submillimeter distances which can be probed by short-range gravity experiments. We show that a torsion pendulum experiment such as Eöt-Wash can exclude symmetrons in this regime for all self-couplings λ is < or approximately equal to 7.5.

A note on the Sagnac effect for matter beams

NASA Astrophysics Data System (ADS)

Ruggiero, Matteo Luca; Tartaglia, Angelo

2015-05-01

We study the Sagnac effect for matter beams, in order to estimate the kinematic corrections to the basic formula, deriving from the position and the extent of the interferometer, and discuss the analogy with the Aharonov-Bohm effect. We show that the formula for the Sagnac time delay is the same for matter and light beams in arbitrary stationary space-times, provided that a suitable condition on the speed of the beams is fulfilled. Hence, the same results obtained for light beams apply to matter beams.

Supersymmetric Model-Building in the Era of LHC Data: From Struggles with Naturalness to the Simple Delights of Fine-Tuning

NASA Astrophysics Data System (ADS)

Zorawski, Thomas

The Standard Model (SM) of particle physics has withstood decades of experimental tests, making it the crowning achievement of 20th century physics. However, it is not a complete description of nature. Observations have revealed that most of the matter in the universe is not of the baryonic form described in the SM but rather something else known as dark matter. The SM also has theoretical shortcomings: 1) No explanation for the widely-varying masses of different particles (flavor puzzle); 2) Failure of the couplings that characterize the strength of the three SM forces to unify at a high energy scale; 3) Instability of the Higgs mass (hierarchy problem). The simplest version of supersymmetry (SUSY) introduces a partner for each SM particle, resulting in the Minimal Supersymmetric Standard Model (MSSM). The lightest of these is stable and an appealing dark matter candidate, and the extra particle content yields good gauge coupling unification. Most model-building, however, has been inspired by the natural solution that the MSSM provides to the hierarchy problem when the superpartner masses are close to the weak scale, leading to the paradigm of the Natural (weak-scale) MSSM. Although the first run of the Large Hadron Collider (LHC) did not operate at the design energy, the data is already in tension with the idea of naturalness, as the bounds on some superpartner masses in vanilla models are significantly above the weak scale. We address this by constructing a hybrid of the two most appealing SUSY breaking mechanisms (gauge and anomaly mediation) that compresses part of the superpartner spectrum and reduces experimental sensitivity, thereby loosening the constraints. Nonetheless, the recent discovery of a Higgs-like particle at the LHC with a mass around 125 GeV that can only be obtained in the weak-scale MSSM with fairly heavy superpartners casts serious doubt on naturalness. It does, however, point in the direction of a different paradigm in the MSSM known as Split SUSY, where only the superpartners that are potential dark matter candidates are light. We present a simple realization of a modification of Split SUSY, called Mini-Split SUSY, where all of the superpartner masses are determined by just one parameter. We show that it easily accommodates the Higgs mass, preserves gauge coupling unification, and has a good dark matter candidate. We then exploit the defining features of the Mini-Split framework to obtain a radiative solution to the flavor puzzle, where the hierarchy of SM particle masses is explained by successive orders of quantum corrections.

Determination of the quasi-TE mode (in-plane) graphene linear absorption coefficient via integration with silicon-on-insulator racetrack cavity resonators.

PubMed

Crowe, Iain F; Clark, Nicholas; Hussein, Siham; Towlson, Brian; Whittaker, Eric; Milosevic, Milan M; Gardes, Frederic Y; Mashanovich, Goran Z; Halsall, Matthew P; Vijayaraghaven, Aravind

2014-07-28

We examine the near-IR light-matter interaction for graphene integrated cavity ring resonators based on silicon-on-insulator (SOI) race-track waveguides. Fitting of the cavity resonances from quasi-TE mode transmission spectra reveal the real part of the effective refractive index for graphene, n(eff) = 2.23 ± 0.02 and linear absorption coefficient, α(gTE) = 0.11 ± 0.01dBμm(-1). The evanescent nature of the guided mode coupling to graphene at resonance depends strongly on the height of the graphene above the cavity, which places limits on the cavity length for optical sensing applications.