Physics of higher orbital bands in optical lattices: a review.

PubMed

Li, Xiaopeng; Liu, W Vincent

2016-11-01

The orbital degree of freedom plays a fundamental role in understanding the unconventional properties in solid state materials. Experimental progress in quantum atomic gases has demonstrated that high orbitals in optical lattices can be used to construct quantum emulators of exotic models beyond natural crystals, where novel many-body states such as complex Bose-Einstein condensates and topological semimetals emerge. A brief introduction of orbital degrees of freedom in optical lattices is given and a summary of exotic orbital models and resulting many-body phases is provided. Experimental consequences of the novel phases are also discussed.

Albert Einstein and his mentor Max Talmey. The seventh Charles B. Snyder Lecture.

PubMed

Ravin, J G

1997-01-01

While he was a student at the Munich medical school, Max Talmey strongly influenced the education of Albert Einstein. Their association occurred during five years of Einstein's second decade. They lost contact for many years after each left Munich. Talmey emigrated to the United States and practiced medicine, mainly ophthalmology, in New York City. He made significant contributions to medicine, to the popularization of Einstein's work, and to the development of international languages. The relationship of Talmey and Einstein was rekindled when Einstein visited and later moved to the United States.

Einstein Observatory solid state spectrometer observations of M87 and the Virgo cluster

NASA Technical Reports Server (NTRS)

Lea, S. M.; Mushotzky, R. F.; Holt, S. S.

1982-01-01

X-ray observations of the galaxy M87 and of a region in the Virgo cluster displaced 7 minutes from the center of M87 are presented. X-ray spectra are obtained at these two locations with the slid state spectrometer onboard the Einstein Observatory. Emission lines were observed in both locations, indicating the presence of heavy elements at abundances approximately solar (to within a factor of 2). A temperature gradient, T increases from approximately 1.4 keV at the position of M87 to T approximately 3.35 keV 7' away, was detected. There is lower temperature thermal emission at the center of M87 with T approximately 0.6 keV, consistent with models for cooling flows in this cluster. In addition to the thermal emission, a power law component in the spectrum of M87, was detected consistent with that observed by HEAO-1, indicating that this component probably originates in the galaxy itself. The presence of intracluster gas having density approximately .001 cu cm and temperature approximately 30 million K is indicated.

Probing Atom-Surface Interactions by Diffraction of Bose-Einstein Condensates

NASA Astrophysics Data System (ADS)

Bender, Helmar; Stehle, Christian; Zimmermann, Claus; Slama, Sebastian; Fiedler, Johannes; Scheel, Stefan; Buhmann, Stefan Yoshi; Marachevsky, Valery N.

2014-01-01

In this article, we analyze the Casimir-Polder interaction of atoms with a solid grating and the repulsive interaction between the atoms and the grating in the presence of an external laser source. The Casimir-Polder potential is evaluated exactly in terms of Rayleigh reflection coefficients and via an approximate Hamaker approach. The laser-tuned repulsive interaction is given in terms of Rayleigh transmission coefficients. The combined potential landscape above the solid grating is probed locally by diffraction of Bose-Einstein condensates. Measured diffraction efficiencies reveal information about the shape of the potential landscape in agreement with the theory based on Rayleigh decompositions.

Einstein's steady-state theory: an abandoned model of the cosmos

NASA Astrophysics Data System (ADS)

O'Raifeartaigh, Cormac; McCann, Brendan; Nahm, Werner; Mitton, Simon

2014-09-01

We present a translation and analysis of an unpublished manuscript by Albert Einstein in which he attempted to construct a `steady-state' model of the universe. The manuscript, which appears to have been written in early 1931, demonstrates that Einstein once explored a cosmic model in which the mean density of matter in an expanding universe is maintained constant by the continuous formation of matter from empty space. This model is very different to previously known Einsteinian models of the cosmos (both static and dynamic) but anticipates the later steady-state cosmology of Hoyle, Bondi and Gold in some ways. We find that Einstein's steady-state model contains a fundamental flaw and suggest that it was abandoned for this reason. We also suggest that he declined to explore a more sophisticated version because he found such theories rather contrived. The manuscript is of historical interest because it reveals that Einstein debated between steady-state and evolving models of the cosmos decades before a similar debate took place in the cosmological community.

Molecular Simulation of the Vapor-Liquid Phase Behavior of Lennard-Jones Mixtures in Porous Solids

DTIC Science & Technology

2006-09-01

sur la Catalyse, Centre National de la Recherche Scientifique, Group de Chimie Theorique, 2 Avenue Albert Einstein, 69626 Villeurbanne Cedex, France...and Group de Chimie Theorique, Ecole Normale Superieure de Lyon, 46 Allee d’Italie, 69364 Lyon, Cedex 07, France 14. ABSTRACT We present vapor...Scientifique, Group de Chimie Theorique, 2 Avenue Albert Einstein, 69626 Villeurbanne Cedex, France and Group de Chimie Theorique, Ecole Normale

Personal Recollections of Albert Einstein

NASA Astrophysics Data System (ADS)

Moszkowski, Steven

2005-03-01

My grandparents were good friends of Albert Einstein in Berlin. Later my parents also were on friendly terms with him. I had the opportunity to meet Einstein four times after my parents and I came to the United States in 1940. My parents and I, on occasion, had correspondence with Einstein and took a few photos of him. Albert Einstein had considerable influence on my development and style of doing physics, as I will discuss.

Equation of state and Helmholtz free energy for the atomic system of the repulsive Lennard-Jones particles.

PubMed

Mirzaeinia, Ali; Feyzi, Farzaneh; Hashemianzadeh, Seyed Majid

2017-12-07

Simple and accurate expressions are presented for the equation of state (EOS) and absolute Helmholtz free energy of a system composed of simple atomic particles interacting through the repulsive Lennard-Jones potential model in the fluid and solid phases. The introduced EOS has 17 and 22 coefficients for fluid and solid phases, respectively, which are regressed to the Monte Carlo (MC) simulation data over the reduced temperature range of 0.6≤T * ≤6.0 and the packing fraction range of 0.1 ≤ η ≤ 0.72. The average absolute relative percent deviation in fitting the EOS parameters to the MC data is 0.06 and 0.14 for the fluid and solid phases, respectively. The thermodynamic integration method is used to calculate the free energy using the MC simulation results. The Helmholtz free energy of the ideal gas is employed as the reference state for the fluid phase. For the solid phase, the values of the free energy at the reduced density equivalent to the close-packed of a hard sphere are used as the reference state. To check the validity of the predicted values of the Helmholtz free energy, the Widom particle insertion method and the Einstein crystal technique of Frenkel and Ladd are employed. The results obtained from the MC simulation approaches are well agreed to the EOS results, which show that the proposed model can reliably be utilized in the framework of thermodynamic theories.

Equation of state and Helmholtz free energy for the atomic system of the repulsive Lennard-Jones particles

NASA Astrophysics Data System (ADS)

Mirzaeinia, Ali; Feyzi, Farzaneh; Hashemianzadeh, Seyed Majid

2017-12-01

Simple and accurate expressions are presented for the equation of state (EOS) and absolute Helmholtz free energy of a system composed of simple atomic particles interacting through the repulsive Lennard-Jones potential model in the fluid and solid phases. The introduced EOS has 17 and 22 coefficients for fluid and solid phases, respectively, which are regressed to the Monte Carlo (MC) simulation data over the reduced temperature range of 0.6 ≤T*≤6.0 and the packing fraction range of 0.1 ≤ η ≤ 0.72. The average absolute relative percent deviation in fitting the EOS parameters to the MC data is 0.06 and 0.14 for the fluid and solid phases, respectively. The thermodynamic integration method is used to calculate the free energy using the MC simulation results. The Helmholtz free energy of the ideal gas is employed as the reference state for the fluid phase. For the solid phase, the values of the free energy at the reduced density equivalent to the close-packed of a hard sphere are used as the reference state. To check the validity of the predicted values of the Helmholtz free energy, the Widom particle insertion method and the Einstein crystal technique of Frenkel and Ladd are employed. The results obtained from the MC simulation approaches are well agreed to the EOS results, which show that the proposed model can reliably be utilized in the framework of thermodynamic theories.

Entanglement Equilibrium and the Einstein Equation.

PubMed

Jacobson, Ted

2016-05-20

A link between the semiclassical Einstein equation and a maximal vacuum entanglement hypothesis is established. The hypothesis asserts that entanglement entropy in small geodesic balls is maximized at fixed volume in a locally maximally symmetric vacuum state of geometry and quantum fields. A qualitative argument suggests that the Einstein equation implies the validity of the hypothesis. A more precise argument shows that, for first-order variations of the local vacuum state of conformal quantum fields, the vacuum entanglement is stationary if and only if the Einstein equation holds. For nonconformal fields, the same conclusion follows modulo a conjecture about the variation of entanglement entropy.

Analysis of LAC Observations of Clusters of Galaxies and Supernova Remnants

NASA Technical Reports Server (NTRS)

Hughes, J.

1996-01-01

The following publications are included and serve as the final report: The X-ray Spectrum of Abell 665; Clusters of Galaxies; Ginga Observation of an Oxygen-rich Supernova Remnant; Ginga Observations of the Coma Cluster and Studies of the Spatial Distribution of Iron; A Measurement of the Hubble Constant from the X-ray Properties and the Sunyaev-Zel'dovich Effect of Abell 2218; Non-polytropic Model for the Coma Cluster; and Abundance Gradients in Cooling Flow Clusters: Ginga LAC (Large Area Counter) and Einstein SSS (Solid State Spectrometer) Spectra of A496, A1795, A2142, and A2199.

Test of Einstein-Podolsky-Rosen Steering Based on the All-Versus-Nothing Proof

PubMed Central

Wu, Chunfeng; Chen, Jing-Ling; Ye, Xiang-Jun; Su, Hong-Yi; Deng, Dong-Ling; Wang, Zhenghan; Oh, C. H.

2014-01-01

In comparison with entanglement and Bell nonlocality, Einstein-Podolsky-Rosen steering is a newly emerged research topic and in its incipient stage. Although Einstein-Podolsky-Rosen steering has been explored via violations of steering inequalities both theoretically and experimentally, the known inequalities in the literatures are far from well-developed. As a result, it is not yet possible to observe Einstein-Podolsky-Rosen steering for some steerable mixed states. Recently, a simple approach was presented to identify Einstein-Podolsky-Rosen steering based on all-versus-nothing argument, offering a strong condition to witness the steerability of a family of two-qubit (pure or mixed) entangled states. In this work, we show that the all-versus-nothing proof of Einstein-Podolsky-Rosen steering can be tested by measuring the projective probabilities. Through the bound of probabilities imposed by local-hidden-state model, the proposed test shows that steering can be detected by the all-versus-nothing argument experimentally even in the presence of imprecision and errors. Our test can be implemented in many physical systems and we discuss the possible realizations of our scheme with non-Abelian anyons and trapped ions. PMID:24598858

Test of Einstein-Podolsky-Rosen steering based on the all-versus-nothing proof.

PubMed

Wu, Chunfeng; Chen, Jing-Ling; Ye, Xiang-Jun; Su, Hong-Yi; Deng, Dong-Ling; Wang, Zhenghan; Oh, C H

2014-03-06

In comparison with entanglement and Bell nonlocality, Einstein-Podolsky-Rosen steering is a newly emerged research topic and in its incipient stage. Although Einstein-Podolsky-Rosen steering has been explored via violations of steering inequalities both theoretically and experimentally, the known inequalities in the literatures are far from well-developed. As a result, it is not yet possible to observe Einstein-Podolsky-Rosen steering for some steerable mixed states. Recently, a simple approach was presented to identify Einstein-Podolsky-Rosen steering based on all-versus-nothing argument, offering a strong condition to witness the steerability of a family of two-qubit (pure or mixed) entangled states. In this work, we show that the all-versus-nothing proof of Einstein-Podolsky-Rosen steering can be tested by measuring the projective probabilities. Through the bound of probabilities imposed by local-hidden-state model, the proposed test shows that steering can be detected by the all-versus-nothing argument experimentally even in the presence of imprecision and errors. Our test can be implemented in many physical systems and we discuss the possible realizations of our scheme with non-Abelian anyons and trapped ions.

From Einstein's theorem to Bell's theorem: a history of quantum non-locality

NASA Astrophysics Data System (ADS)

Wiseman, H. M.

2006-04-01

In this Einstein Year of Physics it seems appropriate to look at an important aspect of Einstein's work that is often down-played: his contribution to the debate on the interpretation of quantum mechanics. Contrary to physics ‘folklore’, Bohr had no defence against Einstein's 1935 attack (the EPR paper) on the claimed completeness of orthodox quantum mechanics. I suggest that Einstein's argument, as stated most clearly in 1946, could justly be called Einstein's reality locality completeness theorem, since it proves that one of these three must be false. Einstein's instinct was that completeness of orthodox quantum mechanics was the falsehood, but he failed in his quest to find a more complete theory that respected reality and locality. Einstein's theorem, and possibly Einstein's failure, inspired John Bell in 1964 to prove his reality locality theorem. This strengthened Einstein's theorem (but showed the futility of his quest) by demonstrating that either reality or locality is a falsehood. This revealed the full non-locality of the quantum world for the first time.

The Media of Relativity: Einstein and Telecommunications Technologies.

PubMed

Canales, Jimena

2015-07-01

How are fundamental constants, such as "c" for the speed of light, related to the technological environments that produce them? Relativistic cosmology, developed first by Albert Einstein, depended on military and commercial innovations in telecommunications. Prominent physicists (Hans Reichenbach, Max Born, Paul Langevin, Louis de Broglie, and Léon Brillouin, among others) worked in radio units during WWI and incorporated battlefield lessons into their research. Relativity physicists, working at the intersection of physics and optics by investigating light and electricity, responded to new challenges by developing a novel scientific framework. Ideas about lengths and solid bodies were overhauled because the old Newtonian mechanics assumed the possibility of "instantaneous signaling at a distance." Einstein's universe, where time and space dilated, where the shortest path between two points was often curved and non-Euclidean, followed the rules of electromagnetic "signal" transmission. For these scientists, light's constant speed in the absence of a gravitational field-a fundamental tenet of Einstein's theory-was a lesson derived from communication technologies.

H + O3 Fourier-transform infrared emission and laser absorption studies of OH(X2Pi) radical - An experimental dipole moment function and state-to-state Einstein A coefficients

NASA Technical Reports Server (NTRS)

Nelson, David D., Jr.; Schiffman, Aram; Nesbitt, David J.; Orlando, John J.; Burkholder, James B.

1990-01-01

FTIR emission/absorption spectroscopy is used to measure the relative intensities of 88 pairs of rovibrational transitions of OH(X2Pi) distributed over 16 vibrational bands. The experimental technique used to obtain the Einstein A ratios is discussed. The dipole moment function which follows from the intensity ratios along with Einstein A coefficients calculated from mu(r) is presented.

Introduction

NASA Astrophysics Data System (ADS)

Bub, Jeffrey; Fuchs, Christopher A.

The great debate between Einstein and Bohr on the interpretation of quantum mechanics culminated with the Einstein-Podolsky-Rosen (EPR) paper in 1935, "Can quantum-mechanical description of physical reality be considered complete?" (Einstein, Podolsky, & Rosen, 1935, and Bohr's reply, 1935). EPR showed that composite quantum systems, consisting of widely separated subsystems, could exist in certain quantum states that they thought spelled trouble for the Copenhagen interpretation. Specifically, they argued that for such states, the correlations between the outcomes of measurements on the subsystems were incompatible with the assumption that the quantum state was a complete description of the system. They concluded that quantum mechanics was an incomplete theory-that the quantum state could not be the whole story about a system.

Celebrating Einstein

NASA Astrophysics Data System (ADS)

Key, Joey; Yunes, Nicolas

2013-04-01

The Gravity Group at Montana State University (MSU) hosted Celebrating Einstein, a free public arts and multimedia event celebrating Einstein and his ideas in Bozeman, Montana April 2-6, 2013. The products of our efforts are now available to any party interested in hosting a similar event. Celebrating Einstein is a truly interdisciplinary effort including art, film, dance, music, physics, history, and education. Events included a black hole immersive art installation, a series of public talks by physicists, and Einstein lessons in the public schools leading up to a live free public multimedia performance including a professional dance company, a live interview with a renowned physicist, and an original score composed for the MSU student symphony to be performed with an original film produced by the Science and Natural History film program at MSU. This project is funded by the Montana Space Grant Consortium, Montana State University, and the National Science Foundation.

Characterization of nonequilibrium states of trapped Bose–Einstein condensates

NASA Astrophysics Data System (ADS)

Yukalov, V. I.; Novikov, A. N.; Bagnato, V. S.

2018-06-01

The generation of different nonequilibrium states in trapped Bose–Einstein condensates is studied by numerically solving the nonlinear Schrödinger equation. Inducing nonequilibrium states by shaking a trap creates the following states: weak nonequilibrium, the state of vortex germs, the state of vortex rings, the state of straight vortex lines, the state of deformed vortices, vortex turbulence, grain turbulence, and wave turbulence. A characterization of nonequilibrium states is advanced by introducing effective temperature, Fresnel number, and Mach number.

Simple cubic equation of state applied to hard-sphere, Lennard-Jones fluids, simple fluids and solids

NASA Astrophysics Data System (ADS)

Sun, Jiu-Xun; Cai, Ling-Cang; Wu, Qiang; Jin, Ke

2013-09-01

Based on the expansion and extension of the virial equation of state (EOS) of hard-sphere fluids solved by the Percus-Yevick integration equation, a universal cubic (UC) EOS is developed. The UC EOS is applied to model hard-sphere and Lennard-Jones (LJ) fluids, simple Ar and N2 liquids at low temperatures, and supercritical Ar and N2 fluids at high temperatures, as well as ten solids, respectively. The three parameters are determined for the hard-sphere fluid by fitting molecular dynamics (MD) simulation data of the third to eighth virial coefficients in the literature; for other fluids by fitting isothermal compression data; and for solids by using the Einstein model. The results show that the UC EOS gives better results than the Carnahan-Starling EOS for compressibility of hard-sphere fluids. The Helmholtz free energy and internal energy for LJ fluids are predicted and compared with MD simulation data. The calculated pressures for simple Ar and N2 liquids are compared with experimental data. The agreement is fairly good. Eight three-parameter EOSs are applied to describe isothermals of ten typical solids. It is shown that the UC EOS gives the best precision with correct behavior at high-pressure limitation. The UC EOS considering thermal effects is used to analytically evaluate the isobaric thermal expansivity and isothermal compressibility coefficients. The results are in good agreement with experimental data.

Einstein coefficients and oscillator strengths for low lying state of CO molecules

NASA Astrophysics Data System (ADS)

Swer, S.; Syiemiong, A.; Ram, M.; Jha, A. K.; Saxena, A.

2018-04-01

Einstein Coefficients and Oscillator Strengths for different state of CO molecule have been calculated using LEROY'S LEVEL program and MOLCAS ab initio code. Using the wave function derived from Morse potential and transition dipole moment obtained from ab initio calculation, The potential energy functions were computed for these states using the spectroscopic constants. The Morse potential of these states and electronic transition dipole moment of the transition calculated in a recent ab initio study have been used in LEVEL program to produce transition dipole matrix element for a large number of bands. Einstein Coefficients have also been used to compute the radiative lifetimes of several vibrational levels and the calculated values are compared with other theoretical results and experimental values.

On-chip generation of Einstein-Podolsky-Rosen states with arbitrary symmetry

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

Gräfe, Markus; Heilmann, René; Nolte, Stefan

We experimentally demonstrate a method for integrated-optical generation of two-photon Einstein-Podolsky-Rosen states featuring arbitrary symmetries. In our setting, we employ detuned directional couplers to impose a freely tailorable phase between the two modes of the state. Our results allow to mimic the quantum random walk statistics of bosons, fermions, and anyons, particles with fractional exchange statistics.

Competition between Bose-Einstein Condensation and Spin Dynamics.

PubMed

Naylor, B; Brewczyk, M; Gajda, M; Gorceix, O; Maréchal, E; Vernac, L; Laburthe-Tolra, B

2016-10-28

We study the impact of spin-exchange collisions on the dynamics of Bose-Einstein condensation by rapidly cooling a chromium multicomponent Bose gas. Despite relatively strong spin-dependent interactions, the critical temperature for Bose-Einstein condensation is reached before the spin degrees of freedom fully thermalize. The increase in density due to Bose-Einstein condensation then triggers spin dynamics, hampering the formation of condensates in spin-excited states. Small metastable spinor condensates are, nevertheless, produced, and they manifest in strong spin fluctuations.

Generating entangled state of Bose-Einstein condensate using electromagnetically induced transparency

NASA Astrophysics Data System (ADS)

Li, Song-Song

2018-01-01

We put forward a scheme on how to generate entangled state of Bose-Einstein condensate (BEC) using electromagnetically induced transparency (EIT). It is shown that we can rapidly generate the entangled state in the dynamical process and the entangled state maintained a long time interval. It is also shown that the better entangled state can be generated by decreasing coupling strengths of two classical laser fields, increasing two-photon detuning and total number of atoms.

Monte Carlo simulations for the free energies of C60 and C70 fullerene crystals by acceptance ratio method and expanded ensemble method

NASA Astrophysics Data System (ADS)

Kim, Minkyu; Chang, Jaeeon; Sandler, Stanley I.

2014-02-01

Accurate values of the free energies of C60 and C70 fullerene crystals are obtained using expanded ensemble method and acceptance ratio method combined with the Einstein-molecule approach. Both simulation methods, when tested for Lennard-Jones crystals, give accurate results of the free energy differing from each other in the fifth significant digit. The solid-solid phase transition temperature of C60 crystal is determined from free energy profiles, and found to be 260 K, which is in good agreement with experiment. For C70 crystal, using the potential model of Sprik et al. [Phys. Rev. Lett. 69, 1660 (1992)], low-temperature solid-solid phase transition temperature is found to be 160 K determined from the free energy profiles. Whereas this is somewhat lower than the experimental value, it is in agreement with conventional molecular simulations, which validates the methodological consistency of the present simulation method. From the calculations of the free energies of C60 and C70 crystals, we note the significance of symmetry number for crystal phase needed to properly account for the indistinguishability of orientationally disordered states.

Einstein-Podolsky-Rosen entanglement and steering in two-well Bose-Einstein-condensate ground states

NASA Astrophysics Data System (ADS)

He, Q. Y.; Drummond, P. D.; Olsen, M. K.; Reid, M. D.

2012-08-01

We consider how to generate and detect Einstein-Podolsky-Rosen (EPR) entanglement and the steering paradox between groups of atoms in two separated potential wells in a Bose-Einstein condensate. We present experimental criteria for this form of entanglement and propose experimental strategies for detecting entanglement using two- or four-mode ground states. These approaches use spatial and/or internal modes. We also present higher-order criteria that act as signatures to detect the multiparticle entanglement present in this system. We point out the difference between spatial entanglement using separated detectors and other types of entanglement that do not require spatial separation. The four-mode approach with two spatial and two internal modes results in an entanglement signature with spatially separated detectors, conceptually similar to the original EPR paradox.

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

Chemical potential of quasi-equilibrium magnon gas driven by pure spin current.

PubMed

Demidov, V E; Urazhdin, S; Divinskiy, B; Bessonov, V D; Rinkevich, A B; Ustinov, V V; Demokritov, S O

2017-11-17

Pure spin currents provide the possibility to control the magnetization state of conducting and insulating magnetic materials. They allow one to increase or reduce the density of magnons, and achieve coherent dynamic states of magnetization reminiscent of the Bose-Einstein condensation. However, until now there was no direct evidence that the state of the magnon gas subjected to spin current can be treated thermodynamically. Here, we show experimentally that the spin current generated by the spin-Hall effect drives the magnon gas into a quasi-equilibrium state that can be described by the Bose-Einstein statistics. The magnon population function is characterized either by an increased effective chemical potential or by a reduced effective temperature, depending on the spin current polarization. In the former case, the chemical potential can closely approach, at large driving currents, the lowest-energy magnon state, indicating the possibility of spin current-driven Bose-Einstein condensation.

Ground-State Wave Function with Interactions between Different Species in M-Component Miscible Bose-Einstein Condensates

NASA Astrophysics Data System (ADS)

Kohno, Wataru; Kirikoshi, Akimitsu; Kita, Takafumi

2018-03-01

We construct a variational ground-state wave function of weakly interacting M-component Bose-Einstein condensates beyond the mean-field theory by incorporating the dynamical 3/2-body processes, where one of the two colliding particles drops into the condensate and vice versa. Our numerical results with various masses and particle numbers show that the 3/2-body processes between different particles make finite contributions to lowering the ground-state energy, implying that many-body correlation effects between different particles are essential even in the weak-coupling regime of the Bose-Einstein condensates. We also consider the stability condition for 2-component miscible states using the new ground-state wave function. Through this calculation, we obtain the relation UAB2/UAAUBB < 1 + α , where Uij is the effective contact potential between particles i and j and α is the correction, which originates from the 3/2- and 2-body processes.

Einstein SSS and MPC observations of Aql X-1 and 4U1820-30

NASA Technical Reports Server (NTRS)

Kelley, R. L.; Christian, D. J.; Schoelkopf, R. J.; Swank, J. H.

1989-01-01

The results of timing and spectral analyses of the X-ray sources Aql X-1 (X1908+005) and 4U1820-30 (NGC6624) are reported using data obtained with the Einstein SSS (Solid State Spectrometer) and MPC (Monitor Proportional Counter) instruments. A classic type I burst was observed from Aql X-1 in both detectors and a coherent modulation with a period of 131.66 + or - 0.02 ms and a pulsed fraction of 10 percent was detected in the SSS data. There is no evidence for a loss of coherance during the approximately 80 sec when the burst is observable. The 2 sigma upper limit on the rate of change of the pulse period is 0.00005s/s. It is argued that an asymmetrical burst occurring on a neutron star rotating at 7.6 Hz offers a plausible explanation for the oscillation. The data from 4U1820-30 show that the amplitude of the 685 sec modulation, identified as the orbital period, is independent of energy down to 0.6 keV. The SSS data show that the light curve in the 0.6 to 4.5 keV band is smoother than at higher energies.

Direct observation of growth and collapse of a Bose-Einstein condensate with attractive interactions

NASA Astrophysics Data System (ADS)

Gerton, Jordan M.; Strekalov, Dmitry; Prodan, Ionut; Hulet, Randall G.

2000-12-01

Quantum theory predicts that Bose-Einstein condensation of a spatially homogeneous gas with attractive interactions is precluded by a conventional phase transition into either a liquid or solid. When confined to a trap, however, such a condensate can form, provided that its occupation number does not exceed a limiting value. The stability limit is determined by a balance between the self-attractive forces and a repulsion that arises from position-momentum uncertainty under conditions of spatial confinement. Near the stability limit, self-attraction can overwhelm the repulsion, causing the condensate to collapse. Growth of the condensate is therefore punctuated by intermittent collapses that are triggered by either macroscopic quantum tunnelling or thermal fluctuation. Previous observations of growth and collapse dynamics have been hampered by the stochastic nature of these mechanisms. Here we report direct observations of the growth and subsequent collapse of a 7Li condensate with attractive interactions, using phase-contrast imaging. The success of the measurement lies in our ability to reduce the stochasticity in the dynamics by controlling the initial number of condensate atoms using a two-photon transition to a diatomic molecular state.

On dynamical systems approaches and methods in f ( R ) cosmology

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

Alho, Artur; Carloni, Sante; Uggla, Claes, E-mail: aalho@math.ist.utl.pt, E-mail: sante.carloni@tecnico.ulisboa.pt, E-mail: claes.uggla@kau.se

We discuss dynamical systems approaches and methods applied to flat Robertson-Walker models in f ( R )-gravity. We argue that a complete description of the solution space of a model requires a global state space analysis that motivates globally covering state space adapted variables. This is shown explicitly by an illustrative example, f ( R ) = R + α R {sup 2}, α > 0, for which we introduce new regular dynamical systems on global compactly extended state spaces for the Jordan and Einstein frames. This example also allows us to illustrate several local and global dynamical systems techniquesmore » involving, e.g., blow ups of nilpotent fixed points, center manifold analysis, averaging, and use of monotone functions. As a result of applying dynamical systems methods to globally state space adapted dynamical systems formulations, we obtain pictures of the entire solution spaces in both the Jordan and the Einstein frames. This shows, e.g., that due to the domain of the conformal transformation between the Jordan and Einstein frames, not all the solutions in the Jordan frame are completely contained in the Einstein frame. We also make comparisons with previous dynamical systems approaches to f ( R ) cosmology and discuss their advantages and disadvantages.« less

α-quantized Einstein masses for leptons, quarks, hadrons, gauge bosons, and Higgs constants

NASA Astrophysics Data System (ADS)

Mac Gregor, Malcolm

2011-11-01

The Einstein particle mass ɛi is defined by the equation ɛi = Ei / c^2. The basic particle ground states have unique additive Einstein masses (energies), and they interleave in α-quantized (α-1 = 137) energy plots to form distinctive excitation patterns. The ɛu,d,s,c,b,t Einstein masses are constituent-quark masses. Particle generation proceeds via ``α-boosted'' boson, fermion, and gauge-boson ``unit masses,'' which are ``bundled'' together to form particles and quarks. The Einstein mass equations extend throughout the entire range of particle masses. Lederman and HillootnotetextL. M. Lederman and C. T. Hill, Symmetry (Prometheus Books, Amherst, 2004), p. 282. note that the scalar Higgs and Fermi fields are at the 175 GeV energy scale of the top quark t, and they suggest the Higgs coupling constant equation ge=me/mt = 0.0000029, which matches the Einstein mass expression ge=α^2/18.

Scalar hair around charged black holes in Einstein-Gauss-Bonnet gravity

NASA Astrophysics Data System (ADS)

Grandi, Nicolás; Landea, Ignacio Salazar

2018-02-01

We explore charged black hole solutions in Einstein-Gauss-Bonnet gravity in five dimensions, with a charged scalar hair. We interpret such hairy black holes as the final state of the superradiant instability previously reported for this system. We explore the relation of the hairy black hole solutions with the nonbackreacting quasibound states and scalar clouds, as well as with the boson star solutions.

Canonical ensemble ground state and correlation entropy of Bose-Einstein condensate

NASA Astrophysics Data System (ADS)

Svidzinsky, Anatoly; Kim, Moochan; Agarwal, Girish; Scully, Marlan O.

2018-01-01

Constraint of a fixed total number of particles yields a correlation between the fluctuation of particles in different states in the canonical ensemble. Here we show that, below the temperature of Bose-Einstein condensation (BEC), the correlation part of the entropy of an ideal Bose gas is cancelled by the ground-state contribution. Thus, in the BEC region, the thermodynamic properties of the gas in the canonical ensemble can be described accurately in a simplified model which excludes the ground state and assumes no correlation between excited levels.

Einstein, Bohr, and Bell

NASA Astrophysics Data System (ADS)

Bellac, Michel Le

2014-11-01

The final form of quantum physics, in the particular case of wave mechanics, was established in the years 1925-1927 by Heisenberg, Schrödinger, Born and others, but the synthesis was the work of Bohr who gave an epistemological interpretation of all the technicalities built up over those years; this interpretation will be examined briefly in Chapter 10. Although Einstein acknowledged the success of quantum mechanics in atomic, molecular and solid state physics, he disagreed deeply with Bohr's interpretation. For many years, he tried to find flaws in the formulation of quantum theory as it had been more or less accepted by a large majority of physicists, but his objections were brushed away by Bohr. However, in an article published in 1935 with Podolsky and Rosen, universally known under the acronym EPR, Einstein thought he had identified a difficulty in the by then standard interpretation. Bohr's obscure, and in part beyond the point, answer showed that Einstein had hit a sensitive target. Nevertheless, until 1964, the so-called Bohr-Einstein debate stayed uniquely on a philosophical level, and it was actually forgotten by most physicists, as the few of them aware of it thought it had no practical implication. In 1964, the Northern Irish physicist John Bell realized that the assumptions contained in the EPR article could be tested experimentally. These assumptions led to inequalities, the Bell inequalities, which were in contradiction with quantum mechanical predictions: as we shall see later on, it is extremely likely that the assumptions of the EPR article are not consistent with experiment, which, on the contrary, vindicates the predictions of quantum physics. In Section 3.2, the origin of Bell's inequalities will be explained with an intuitive example, then they will be compared with the predictions of quantum theory in Section 3.3, and finally their experimental status will be reviewed in Section 3.4. The debate between Bohr and Einstein goes much beyond a simple controversy, which is after all almost eighty years old and has been settled today. In fact, the concept introduced in this debate, that of entanglement, lies at the heart of many very important developments of modern quantum physics, in particular all those linked to quantum information (Chapter 8). Moreover, we shall see that the phenomenon of non-local correlations compels us to revise in depth our space-time representation of quantum processes. These are the two reasons why a whole chapter is devoted to this debate.

Mass-induced instability of SAdS black hole in Einstein-Ricci cubic gravity

NASA Astrophysics Data System (ADS)

Myung, Yun Soo

2018-05-01

We perform the stability analysis of Schwarzschild-AdS (SAdS) black hole in the Einstein-Ricci cubic gravity. It shows that the Ricci tensor perturbations exhibit unstable modes for small black holes. We call this the mass-induced instability of SAdS black hole because the instability of small black holes arises from the massiveness in the linearized Einstein-Ricci cubic gravity, but not a feature of higher-order derivative theory giving ghost states. Also, we point out that the correlated stability conjecture holds for the SAdS black hole by computing the Wald entropy of SAdS black hole in Einstein-Ricci cubic gravity.

Standard Entropy of Crystalline Iodine from Vapor Pressure Measurements: A Physical Chemistry Experiment.

ERIC Educational Resources Information Center

Harris, Ronald M.

1978-01-01

Presents material dealing with an application of statistical thermodynamics to the diatomic solid I-2(s). The objective is to enhance the student's appreciation of the power of the statistical formulation of thermodynamics. The Simple Einstein Model is used. (Author/MA)

Instability of Bose-Einstein condensation into the one-particle ground state on quantum graphs under repulsive perturbations

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

Bolte, Jens, E-mail: jens.bolte@rhul.ac.uk; Kerner, Joachim, E-mail: joachim.kerner@fernuni-hagen.de

In this paper we investigate Bose-Einstein condensation into the one-particle ground state in interacting quantum many-particle systems on graphs. We extend previous results obtained for particles on an interval and show that even arbitrarily small repulsive two-particle interactions destroy the condensate in the one-particle ground state present in the non-interacting Bose gas. Our results also cover singular two-particle interactions, such as the well-known Lieb-Liniger model, in the thermodynamic limit.

A relativistic coupled-cluster interaction potential and rovibrational constants for the xenon dimer

NASA Astrophysics Data System (ADS)

Jerabek, Paul; Smits, Odile; Pahl, Elke; Schwerdtfeger, Peter

2018-01-01

An accurate potential energy curve has been derived for the xenon dimer using state-of-the-art relativistic coupled-cluster theory up to quadruple excitations accounting for both basis set superposition and incompleteness errors. The data obtained is fitted to a computationally efficient extended Lennard-Jones potential form and to a modified Tang-Toennies potential function treating the short- and long-range part separately. The vibrational spectrum of Xe2 obtained from a numerical solution of the rovibrational Schrödinger equation and subsequently derived spectroscopic constants are in excellent agreement with experimental values. We further present solid-state calculations for xenon using a static many-body expansion up to fourth-order in the xenon interaction potential including dynamic effects within the Einstein approximation. Again we find very good agreement with the experimental (face-centred cubic) lattice constant and cohesive energy.

Large Fizeau's light-dragging effect in a moving electromagnetically induced transparent medium.

PubMed

Kuan, Pei-Chen; Huang, Chang; Chan, Wei Sheng; Kosen, Sandoko; Lan, Shau-Yu

2016-10-03

As one of the most influential experiments on the development of modern macroscopic theory from Newtonian mechanics to Einstein's special theory of relativity, the phenomenon of light dragging in a moving medium has been discussed and observed extensively in different types of systems. To have a significant dragging effect, the long duration of light travelling in the medium is preferred. Here we demonstrate a light-dragging experiment in an electromagnetically induced transparent cold atomic ensemble and enhance the dragging effect by at least three orders of magnitude compared with the previous experiments. With a large enhancement of the dragging effect, we realize an atom-based velocimeter that has a sensitivity two orders of magnitude higher than the velocity width of the atomic medium used. Such a demonstration could pave the way for motional sensing using the collective state of atoms in a room temperature vapour cell or solid state material.

Quantum-metric contribution to the pair mass in spin-orbit-coupled Fermi superfluids

NASA Astrophysics Data System (ADS)

Iskin, M.

2018-03-01

As a measure of the quantum distance between Bloch states in the Hilbert space, the quantum metric was introduced to solid-state physics through the real part of the so-called geometric Fubini-Study tensor, the imaginary part of which corresponds to the Berry curvature measuring the emergent gauge field in momentum space. Here, we first derive the Ginzburg-Landau theory near the critical superfluid transition temperature and then identify and analyze the geometric effects on the effective mass tensor of the Cooper pairs. By showing that the quantum-metric contribution accounts for a sizable fraction of the pair mass in a surprisingly large parameter regime throughout the BCS-Bose-Einstein condensate crossover, we not only reveal the physical origin of its governing role in the superfluid density tensor but also hint at its plausible roles in many other observables.

X-rays from Eta Carinae

NASA Technical Reports Server (NTRS)

Chlebowski, T.; Seward, F. D.; Swank, J.; Szymkowiak, A.

1984-01-01

X-ray observations of Eta Car obtained with the high-resolution imager and solid-state spectrometer of the Einstein observatory are reported and interpreted in terms of a two-shell model. A soft component with temperature 5 million K is located in the expanding outer shell, and the hard core component with temperature 80 million K is attributed to the interaction of a high-velocity stellar wind from the massive central object with the inner edge of a dust shell. Model calculations based on comparison with optical and IR data permit estimation of the mass of the outer shell (0.004 solar mass), the mass of the dust shell (3 solar mass), and the total shell expansion energy (less than 2 x 10 to the 49th ergs).

Theoretical Dipole Moment for the X211 State of NO

NASA Technical Reports Server (NTRS)

Langhoff, Stephen R.; Bauschlicher, Charles W., Jr.; Partridge, Harry; Arnold, James O. (Technical Monitor)

1994-01-01

The dipole moment function for the X(sup 2)II state of NO is studied as a function of the completeness in both the one- and n-particle spaces. Einstein coefficients are presented that are significantly more accurate than previous tabulations for the higher vibrational levels. The theoretical values give considerable insight into the limitations of recently published ratios of Einstein coefficients measured by spectrally resolved infrared chemiluminescence.

Induced matter brane gravity and Einstein static universe

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

Heydarzade, Y.; Darabi, F., E-mail: heydarzade@azaruniv.edu, E-mail: f.darabi@azaruniv.edu

We investigate stability of the Einstein static universe against the scalar, vector and tensor perturbations in the context of induced matter brane gravity. It is shown that in the framework of this model, the Einstein static universe has a positive spatial curvature. In contrast to the classical general relativity, it is found that a stable Einstein static universe against the scalar perturbations does exist provided that the variation of time dependent geometrical equation of state parameter is proportional to the minus of the variation of the scale factor, δ ω{sub g}(t) = −Cδ a(t). We obtain neutral stability against the vector perturbations, and themore » stability against the tensor perturbations is guaranteed due to the positivity of the spatial curvature of the Einstein static universe in induced matter brane gravity.« less

Einstein Equations from Varying Complexity

NASA Astrophysics Data System (ADS)

Czech, Bartłomiej

2018-01-01

A recent proposal equates the circuit complexity of a quantum gravity state with the gravitational action of a certain patch of spacetime. Since Einstein's equations follow from varying the action, it should be possible to derive them by varying complexity. I present such a derivation for vacuum solutions of pure Einstein gravity in three-dimensional asymptotically anti-de Sitter space. The argument relies on known facts about holography and on properties of tensor network renormalization, an algorithm for coarse-graining (and optimizing) tensor networks.

Synthetic clock states generated in a Bose-Einstein condensate via continuous dynamical decoupling

NASA Astrophysics Data System (ADS)

Lundblad, Nathan; Trypogeorgos, Dimitrios; Valdes-Curiel, Ana; Marshall, Erin; Spielman, Ian

2017-04-01

Radiofrequency- or microwave-dressed states have been used in NV center and ion-trap experiments to extend coherence times, shielding qubits from magnetic field noise through a process known as continuous dynamical decoupling. Such field-insensitive dressed states, as applied in the context of ultracold neutral atoms, have applications related to the creation of novel phases of spin-orbit-coupled quantum matter. We present observations of such a protected dressed-state system in a Bose-Einstein condensate, including measurements of the dependence of the protection on rf coupling strength, and estimates of residual field sensitivities.

One Part Nuclear, One Part Solid State: Fifty Years of Mössbauer Spectroscopy

NASA Astrophysics Data System (ADS)

Westfall, Catherine

2004-05-01

Starting in 1955 Rudolf Mössbauer conducted experiments that would demonstrate in the next three years that an atomic nucleus in a crystal does not recoil when it emits a gamma ray and provides the entire emitted energy to the gamma ray. The resonance spectroscopy made possible by this discovery led to fifty years of scientific explorations in a wide variety of fields including nuclear and solid state physics, chemistry, and geology. At the current time, Mössbauer spectroscopy is a vital part of science programs, both in many laboratories and at world-class light sources, such as Argonnes Advanced Photon Source. This paper will focus on the history of multidisciplinary Mössbauer research at Argonne National Laboratory and particularly on the interaction between nuclear and condensed matter physicists. This was necessary because of the ultra-high energy resolution of the Mössbauer resonance with its ability to resolve hyperfine interactions between the nuclear moments (nuclear charge distribution, the nuclear magnetic moment, and nuclear quadrupole moment) and corresponding solid state properties (electron charge distribution at the nucleus, magnetic field at the nucleus, and electric field gradient at the nucleus.) Understanding and exploiting Mössbauer spectroscopy therefore required work at the intersection of nuclear and solid state physics and the skills and knowledge of both specialties. The paper will start with the discovery and confirmation of the Mössbauer effect. Then it will outline early important experiments, such as the use of Mössbauer spectroscopy to confirm Einsteins general theory of relativity, and give an overview of the rapid expansion of this research tool, first with the use of Fe57 and later with the use of other isotopes. In particular the paper will focus on Argonnes cutting-edge Mössbauer work on transuranics. This work built on the resources and expertise first developed at the laboratory during WWII and brought together not only nuclear and condensed matter physicists, but also chemists, material scientists, and others.

Genuine multipartite Einstein-Podolsky-Rosen steering.

PubMed

He, Q Y; Reid, M D

2013-12-20

We develop the concept of genuine N-partite Einstein-Podolsky-Rosen (EPR) steering. This nonlocality is the natural multipartite extension of the original EPR paradox. Useful properties emerge that are not guaranteed for genuine multipartite entangled states. In particular, there is a close link with the task of one-sided, device-independent quantum secret sharing. We derive inequalities to demonstrate multipartite EPR steering for Greenberger-Horne-Zeilinger and Gaussian continuous variable states in loophole-free scenarios.

Genuine Multipartite Einstein-Podolsky-Rosen Steering

NASA Astrophysics Data System (ADS)

He, Q. Y.; Reid, M. D.

2013-12-01

We develop the concept of genuine N-partite Einstein-Podolsky-Rosen (EPR) steering. This nonlocality is the natural multipartite extension of the original EPR paradox. Useful properties emerge that are not guaranteed for genuine multipartite entangled states. In particular, there is a close link with the task of one-sided, device-independent quantum secret sharing. We derive inequalities to demonstrate multipartite EPR steering for Greenberger-Horne-Zeilinger and Gaussian continuous variable states in loophole-free scenarios.

Breakdown of Bose-Einstein distribution in photonic crystals.

PubMed

Lo, Ping-Yuan; Xiong, Heng-Na; Zhang, Wei-Min

2015-03-30

In the last two decades, considerable advances have been made in the investigation of nano-photonics in photonic crystals. Previous theoretical investigations of photon dynamics were carried out at zero temperature. Here, we investigate micro/nano cavity photonics in photonic crystals at finite temperature. Due to photonic-band-gap-induced localized long-lived photon dynamics, we discover that cavity photons in photonic crystals do not obey Bose-Einstein statistical distribution. Within the photonic band gap and in the vicinity of the band edge, cavity photons combine the long-lived non-Markovain dynamics with thermal fluctuations together to form photon states that memorize the initial cavity state information. As a result, Bose-Einstein distribution is completely broken down in these regimes, even if the thermal energy is larger or much larger than the cavity detuning energy. In this investigation, a crossover phenomenon from equilibrium to nonequilibrium steady states is also revealed.

Breakdown of Bose-Einstein Distribution in Photonic Crystals

PubMed Central

Lo, Ping-Yuan; Xiong, Heng-Na; Zhang, Wei-Min

2015-01-01

In the last two decades, considerable advances have been made in the investigation of nano-photonics in photonic crystals. Previous theoretical investigations of photon dynamics were carried out at zero temperature. Here, we investigate micro/nano cavity photonics in photonic crystals at finite temperature. Due to photonic-band-gap-induced localized long-lived photon dynamics, we discover that cavity photons in photonic crystals do not obey Bose-Einstein statistical distribution. Within the photonic band gap and in the vicinity of the band edge, cavity photons combine the long-lived non-Markovain dynamics with thermal fluctuations together to form photon states that memorize the initial cavity state information. As a result, Bose-Einstein distribution is completely broken down in these regimes, even if the thermal energy is larger or much larger than the cavity detuning energy. In this investigation, a crossover phenomenon from equilibrium to nonequilibrium steady states is also revealed. PMID:25822135

Spatial Bose-Einstein Condensation.

ERIC Educational Resources Information Center

Masut, Remo; Mullin, William J.

1979-01-01

Analyzes three examples of spatial Bose-Einstein condensations in which the particles macroscopically occupy the lowest localized state of an inhomogeneous external potential. The three cases are (1) a box with a small square potential well inside, (2) a harmonic oscillator potential, and (3) randomly sized trapping potentials caused by…

X-ray observations of EX Hydrae with the Einstein Solid State Spectrometer

NASA Technical Reports Server (NTRS)

Singh, Jyoti; Swank, Jean

1993-01-01

Einstein SSS X-ray observations of the eclipsing intermediate polar EX Hya are presented. The SSS data have a better resolution at energies extending below 2 keV than do the EXOSAT data. These data reveal the presence of a soft component with a temperature of about 0.74 keV. The phase-resolved data can be fitted to a model of two-temperature thermal plasma with a single absorber, with the result that only the normalization varies with phase. This suggests that part of the soft component might become occulted at minimum. If we assume that the reduction in the flux occurs due to the photoelectric absorption, we find that a high-density material covering only about 40 percent of the emission can fit the data equally well. The EXOSAT and Ginga data of this source favor the accretion curtain model rather than the occultation model. We modify the accretion curtain model by assuming that the modulation is caused by an absorber which partially covers the accreting column at the minimum of the 67-min pulse. An emission line at 1.72 keV is present in the data. The equivalent width of this line varies in phase with the continuum. We associate this line with Si fluorescence.

X-ray properties of the Be/X-ray system 28 0114+650 = LSI +65deg 010

NASA Technical Reports Server (NTRS)

Koenigsberger, G.; Swank, J. H.; Szymkowiak, A. E.; White, N. E.

1983-01-01

Results are presented from experiments on the Einstein Observatory, HEAO 1, and OSO 8 on the temporal and spectral properties of 2S 0114+650. In a 12 hr Einstein monitor proportional counter and solid state spectrometer observation, two episodes of flaring occurred by an order of magnitude over about 1 hr. Variability on shorter time scales showed a preferred period of 14.9 minutes, but periodic pulsations were not seen in the HEAO 1 and OSO 8 data. The spectra above 1 keV were typical of accreting X-ray pulsars; the power law was E exp -alpha with alpha of about 1.2 for the number spectrum up to a cutoff at 14 keV. There is some evidence that the spectrum is steeper when the source is quiescent at low luminosity, but no large spectral changes attended the flares. Absorption column densities were consistent with interstellar reddening of the proposed companion, the Be star LSI +65 deg010. In the minute and hour variability and in the spectral character, 2S0114+650 is similar to other Be star-neutron star binary X-ray sources. Variations over several days in the OSO 8 data suggest orbital effects.

The forces on a single interacting Bose-Einstein condensate

NASA Astrophysics Data System (ADS)

Thu, Nguyen Van

2018-04-01

Using double parabola approximation for a single Bose-Einstein condensate confined between double slabs we proved that in grand canonical ensemble (GCE) the ground state with Robin boundary condition (BC) is favored, whereas in canonical ensemble (CE) our system undergoes from ground state with Robin BC to the one with Dirichlet BC in small-L region and vice versa for large-L region and phase transition in space of the ground state is the first order. The surface tension force and Casimir force are also considered in both CE and GCE in detail.

Modified fluctuation-dissipation and Einstein relation at nonequilibrium steady states

NASA Astrophysics Data System (ADS)

Chaudhuri, Debasish; Chaudhuri, Abhishek

2012-02-01

Starting from the pioneering work of Agarwal [G. S. Agarwal, Zeitschrift für PhysikEPJAFV1434-600110.1007/BF01391621 252, 25 (1972)], we present a unified derivation of a number of modified fluctuation-dissipation relations (MFDR) that relate response to small perturbations around nonequilibrium steady states to steady-state correlations. Using this formalism we show the equivalence of velocity forms of MFDR derived using continuum Langevin and discrete master equation dynamics. The resulting additive correction to the Einstein relation is exemplified using a flashing ratchet model of molecular motors.

Einstein-Podolsky-Rosen steering and coherence in the family of entangled three-qubit states

NASA Astrophysics Data System (ADS)

Kalaga, J. K.; Leoński, W.; Peřina, J.

2018-04-01

Considering the system of three interacting qubits, we analyze four families of states from the point of view of bipartite correlations appearing in two-qubit subsystems of a three-qubit model, such as Einstein-Podolsky-Rosen steering, entanglement, and coherence. We reveal mutual relations among the steering parameter, concurrence, and three measures of coherence (degree of coherence, first-, and second-order correlation functions). Analyzing in parallel the steerable and unsteerable states, we derive analytical formulas giving the maximal and minimal values of coherence measures as concurrence varies.

Bose-Einstein condensation in an ultra-hot gas of pumped magnons.

PubMed

Serga, Alexander A; Tiberkevich, Vasil S; Sandweg, Christian W; Vasyuchka, Vitaliy I; Bozhko, Dmytro A; Chumak, Andrii V; Neumann, Timo; Obry, Björn; Melkov, Gennadii A; Slavin, Andrei N; Hillebrands, Burkard

2014-03-11

Bose-Einstein condensation of quasi-particles such as excitons, polaritons, magnons and photons is a fascinating quantum mechanical phenomenon. Unlike the Bose-Einstein condensation of real particles (like atoms), these processes do not require low temperatures, since the high densities of low-energy quasi-particles needed for the condensate to form can be produced via external pumping. Here we demonstrate that such a pumping can create remarkably high effective temperatures in a narrow spectral region of the lowest energy states in a magnon gas, resulting in strikingly unexpected transitional dynamics of Bose-Einstein magnon condensate: the density of the condensate increases immediately after the external magnon flow is switched off and initially decreases if it is switched on again. This behaviour finds explanation in a nonlinear 'evaporative supercooling' mechanism that couples the low-energy magnons overheated by pumping with all the other thermal magnons, removing the excess heat, and allowing Bose-Einstein condensate formation.

Quantum noise of a Bose-Einstein condensate in an optical cavity, correlations, and entanglement

NASA Astrophysics Data System (ADS)

Szirmai, G.; Nagy, D.; Domokos, P.

2010-04-01

A Bose-Einstein condensate of ultracold atoms inside the field of a laser-driven optical cavity exhibits dispersive optical bistability. We describe this system by using mean-field approximation and by analyzing the correlation functions of the linearized quantum fluctuations around the mean-field solution. The entanglement and the statistics of the atom-field quadratures are given in the stationary state. It is shown that the mean-field solution, that is, the Bose-Einstein condensate, is robust against entanglement generation for most of the phase diagram.

Vector dark-antidark solitary waves in multicomponent Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Danaila, I.; Khamehchi, M. A.; Gokhroo, V.; Engels, P.; Kevrekidis, P. G.

2016-11-01

Multicomponent Bose-Einstein condensates exhibit an intriguing variety of nonlinear structures. In recent theoretical work [C. Qu, L. P. Pitaevskii, and S. Stringari, Phys. Rev. Lett. 116, 160402 (2016), 10.1103/PhysRevLett.116.160402], the notion of magnetic solitons has been introduced. Here we examine a variant of this concept in the form of vector dark-antidark solitary waves in multicomponent Bose-Einstein condensates (BECs). We first provide concrete experimental evidence for such states in an atomic BEC and subsequently illustrate the broader concept of these states, which are based on the interplay between miscibility and intercomponent repulsion. Armed with this more general conceptual framework, we expand the notion of such states to higher dimensions presenting the possibility of both vortex-antidark states and ring-antidark-ring (dark soliton) states. We perform numerical continuation studies, investigate the existence of these states, and examine their stability using the method of Bogoliubov-de Gennes analysis. Dark-antidark and vortex-antidark states are found to be stable for broad parametric regimes. In the case of ring dark solitons, where the single-component ring state is known to be unstable, the vector entity appears to bear a progressively more and more stabilizing role as the intercomponent coupling is increased.

Einstein and Millikan

NASA Astrophysics Data System (ADS)

Erwin, Charlotte

2005-03-01

Albert Einstein traveled to America by boat during the great depression to consult with scientists at the California Institute of Technology. He was a theoretical physicist, a Nobel Prize winner, and a 20th century folk hero. Few members of the general public understood his theories, but they idolized him all the same. The invitation came from physicist Robert Millikan, who had initiated a visiting-scholars program at Caltech shortly after he became head of the school in 1921. Einstein's visits to the campus in 1931, 1932, and 1933 capped Millikan's campaign to make Caltech one of the physics capitals of the world. Mount Wilson astronomer Edwin Hubble's discovery that redshifts are proportional to their distances from the observer challenged Einstein's cosmological picture of a static universe. The big question at Caltech in 1931 was whether Einstein would give up his cosmological constant and accept the idea of an expanding universe. By day, Einstein discussed his theory and its interpretation at length with Richard Tolman, Hubble, and the other scientists on the campus. By night, Einstein filled his travel diary with his personal impressions. During his third visit, Einstein sidestepped as long as possible the question of whether conditions in Germany might prevent his return there. After the January 30 announcement that Hitler had become chancellor of Germany, the question could no longer be evaded. He postponed his return trip for a few weeks and then went to Belgium for several months instead of to Berlin. In the fall of 1933, Albert Einstein returned to the United States as an emigre and became a charter member of Abraham Flexner's new Institute for Advanced Study in Princeton, New Jersey. Why did Einstein go to Princeton and not Pasadena?

Interprofessional student education: exchange program between Albert Einstein College of Medicine and Pacific College of Oriental Medicine.

PubMed

Anderson, Belinda J; Herron, Patrick D; Downie, Sherry A; Myers, Daniel C; Milan, Felise B; Olson, Todd R; Kligler, Ben E; Sierpina, Victor S; Kreitzer, Mary Jo

2012-01-01

The growing popularity of complementary and alternative medicine (CAM), of which estimated 38% of adults in the United States used in 2007, has engendered changes in medical school curricula to increase students' awareness of it. Exchange programs between conventional medical schools and CAM institutions are recognized as an effective method of interprofessional education. The exchange program between Albert Einstein College of Medicine (Einstein, Yeshiva University) and Pacific College of Oriental Medicine, New York campus (PCOM-NY) is in its fifth year and is part of a broader relationship between the schools encompassing research, clinical training, interinstitutional faculty and board appointments, and several educational activities. The Einstein/PCOM-NY student education exchange program is part of the Einstein Introduction to Clinical Medicine Program and involves students from Einstein learning about Chinese medicine through a lecture, the experience of having acupuncture, and a four-hour preceptorship at the PCOM outpatient clinic. The students from PCOM learn about allopathic medicine training through an orientation lecture, a two-and-a-half-hour dissection laboratory session along side Einstein student hosts, and a tour of the clinical skills center at the Einstein campus. In the 2011/2012 offering of the exchange program, the participating Einstein and PCOM students were surveyed to assess the educational outcomes. The data indicate that the exchange program was highly valued by all students and provided a unique learning experience. Survey responses from the Einstein students indicated the need for greater emphasis on referral information, which has been highlighted in the literature as an important medical curriculum integrative medicine competency. Copyright © 2012 Elsevier Inc. All rights reserved.

Exciton-polariton trapping and potential landscape engineering

NASA Astrophysics Data System (ADS)

Schneider, C.; Winkler, K.; Fraser, M. D.; Kamp, M.; Yamamoto, Y.; Ostrovskaya, E. A.; Höfling, S.

2017-01-01

Exciton-polaritons in semiconductor microcavities have become a model system for the studies of dynamical Bose-Einstein condensation, macroscopic coherence, many-body effects, nonclassical states of light and matter, and possibly quantum phase transitions in a solid state. These low-mass bosonic quasiparticles can condense at comparatively high temperatures up to 300 K, and preserve the fundamental properties of the condensate, such as coherence in space and time domain, even when they are out of equilibrium with the environment. Although the presence of a confining potential is not strictly necessary in order to observe Bose-Einstein condensation, engineering of the polariton confinement is a key to controlling, shaping, and directing the flow of polaritons. Prototype polariton-based optoelectronic devices rely on ultrafast photon-like velocities and strong nonlinearities exhibited by polaritons, as well as on their tailored confinement. Nanotechnology provides several pathways to achieving polariton confinement, and the specific features and advantages of different methods are discussed in this review. Being hybrid exciton-photon quasiparticles, polaritons can be trapped via their excitonic as well as photonic component, which leads to a wide choice of highly complementary trapping techniques. Here, we highlight the almost free choice of the confinement strengths and trapping geometries that provide powerful means for control and manipulation of the polariton systems both in the semi-classical and quantum regimes. Furthermore, the possibilities to observe effects of the polariton blockade, Mott insulator physics, and population of higher-order energy bands in sophisticated lattice potentials are discussed. Observation of such effects could lead to realization of novel polaritonic non-classical light sources and quantum simulators.

Cooper pair splitter realized in a two-quantum-dot Y-junction.

PubMed

Hofstetter, L; Csonka, S; Nygård, J; Schönenberger, C

2009-10-15

Non-locality is a fundamental property of quantum mechanics that manifests itself as correlations between spatially separated parts of a quantum system. A fundamental route for the exploration of such phenomena is the generation of Einstein-Podolsky-Rosen (EPR) pairs of quantum-entangled objects for the test of so-called Bell inequalities. Whereas such experimental tests of non-locality have been successfully conducted with pairwise entangled photons, it has not yet been possible to realize an electronic analogue of it in the solid state, where spin-1/2 mobile electrons are the natural quantum objects. The difficulty stems from the fact that electrons are immersed in a macroscopic ground state-the Fermi sea-which prevents the straightforward generation and splitting of entangled pairs of electrons on demand. A superconductor, however, could act as a source of EPR pairs of electrons, because its ground-state is composed of Cooper pairs in a spin-singlet state. These Cooper pairs can be extracted from a superconductor by tunnelling, but, to obtain an efficient EPR source of entangled electrons, the splitting of the Cooper pairs into separate electrons has to be enforced. This can be achieved by having the electrons 'repel' each other by Coulomb interaction. Controlled Cooper pair splitting can thereby be realized by coupling of the superconductor to two normal metal drain contacts by means of individually tunable quantum dots. Here we demonstrate the first experimental realization of such a tunable Cooper pair splitter, which shows a surprisingly high efficiency. Our findings open a route towards a first test of the EPR paradox and Bell inequalities in the solid state.

Qubit Residence Time Measurements with a Bose-Einstein Condensate

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

Sokolovski, D.

2009-06-12

We show that an electrostatic qubit located near a Bose-Einstein condensate trapped in a symmetric double-well potential can be used to measure the duration the qubit has spent in one of its quantum states. The strong, medium, and weak measurement regimes are analyzed. The analogy between the residence and the traversal (tunnelling) times is highlighted.

Equivalence principles and electromagnetism

NASA Technical Reports Server (NTRS)

Ni, W.-T.

1977-01-01

The implications of the weak equivalence principles are investigated in detail for electromagnetic systems in a general framework. In particular, it is shown that the universality of free-fall trajectories (Galileo weak equivalence principle) does not imply the validity of the Einstein equivalence principle. However, the Galileo principle plus the universality of free-fall rotation states does imply the Einstein principle.

Albert Einstein: Radical Pacifist and Democrat

NASA Astrophysics Data System (ADS)

Jayaraman, T.

We draw attention here to the radical political grounding of Einstein's pacifism. We also drescribe some less commonly known aspects of his commitment to civil liberties, particularly in the context of the anti-l hysteria and anti-racism current in the United States of the late 1940s and 1950s. We also examine briefly his views on socialism.

Pair-correlation function of a metastable helium Bose-Einstein condensate

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

Zin, Pawel; Trippenbach, Marek; Gajda, Mariusz

2004-02-01

The pair-correlation function is one of the basic quantities to characterize the coherence properties of a Bose-Einstein condensate. We calculate this function in the experimentally important case of a zero temperature Bose-Einstein condensate in a metastable triplet helium state using the variational method with a pair-excitation ansatz. We compare our result with a pair-correlation function obtained for the hard-sphere potential with the same scattering length. Both functions are practically indistinguishable for distances greater than the scattering length. At smaller distances, due to interatomic interactions, the helium condensate shows strong correlations.

Modeling Bose-Einstein correlations via elementary emitting cells

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

Utyuzh, Oleg; Wilk, Grzegorz; Wlodarczyk, Zbigniew

2007-04-01

We propose a method of numerical modeling Bose-Einstein correlations by using the notion of the elementary emitting cell (EEC). They are intermediary objects containing identical bosons and are supposed to be produced independently during the hadronization process. Only bosons in the EEC, which represents a single quantum state here, are subjected to the effects of Bose-Einstein (BE) statistics, which forces them to follow a geometrical distribution. There are no such effects between particles from different EECs. We illustrate our proposition by calculating a representative number of typical distributions and discussing their sensitivity to EECs and their characteristics.

Localization of one-photon state in space and Einstein-Podolsky-Rosen paradox in spontaneous parametric down conversion

NASA Technical Reports Server (NTRS)

Penin, A. N.; Reutova, T. A.; Sergienko, A. V.

1992-01-01

An experiment on one-photon state localization in space using a correlation technique in Spontaneous Parametric Down Conversion (SPDC) process is discussed. Results of measurements demonstrate an idea of the Einstein-Podolsky-Rosen (EPR) paradox for coordinate and momentum variables of photon states. Results of the experiment can be explained with the help of an advanced wave technique. The experiment is based on the idea that two-photon states of optical electromagnetic fields arising in the nonlinear process of the spontaneous parametric down conversion (spontaneous parametric light scattering) can be explained by quantum mechanical theory with the help of a single wave function.

Localization of one-photon state in space and Einstein-Podolsky-Rosen paradox in spontaneous parametric down conversion

NASA Astrophysics Data System (ADS)

Penin, A. N.; Reutova, T. A.; Sergienko, A. V.

1992-02-01

An experiment on one-photon state localization in space using a correlation technique in Spontaneous Parametric Down Conversion (SPDC) process is discussed. Results of measurements demonstrate an idea of the Einstein-Podolsky-Rosen (EPR) paradox for coordinate and momentum variables of photon states. Results of the experiment can be explained with the help of an advanced wave technique. The experiment is based on the idea that two-photon states of optical electromagnetic fields arising in the nonlinear process of the spontaneous parametric down conversion (spontaneous parametric light scattering) can be explained by quantum mechanical theory with the help of a single wave function.

X-ray emission from clusters of galaxies

NASA Technical Reports Server (NTRS)

Mushotzky, R. F.

1983-01-01

Some X-ray spectral observations of approximately 30 clusters of galaxies from HEAO-1 are summarized. There exists strong correlations between X-ray luminosity, L(x), and temperature kT in the form L(x)alphaT to the 2.3 power. This result combined with the L(x) central galaxy density relation and the virial theorem indicates that the core dadius of the gas should be roughly independent of L(x) or KT and that more luminous clusters have a greater fraction of their virial mass in gas. The poor correlation of KT and optical velocity dispersion seems to indicate that clusters have a variety of equations of state. There is poor agreement between X-ray imaging observations and optical and X-ray spectral measures of the polytropic index. Most clusters show Fe emission lines with a strong indication that they all have roughly 1/2 solar abundance. The evidence for cooling in the cores of several clusters is discussed based on spectral observations with the Einstein solid state spectrometer.

PT -symmetric gain and loss in a rotating Bose-Einstein condensate

NASA Astrophysics Data System (ADS)

Haag, Daniel; Dast, Dennis; Cartarius, Holger; Wunner, Günter

2018-03-01

PT -symmetric quantum mechanics allows finding stationary states in mean-field systems with balanced gain and loss of particles. In this work we apply this method to rotating Bose-Einstein condensates with contact interaction which are known to support ground states with vortices. Due to the particle exchange with the environment transport phenomena through ultracold gases with vortices can be studied. We find that even strongly interacting rotating systems support stable PT -symmetric ground states, sustaining a current parallel and perpendicular to the vortex cores. The vortices move through the nonuniform particle density and leave or enter the condensate through its borders creating the required net current.

Stationary states and rotational properties of spin-orbit-coupled Bose-Einstein condensates held under a toroidal trap

NASA Astrophysics Data System (ADS)

He, Zhang-Ming; Zhang, Xiao-Fei; Kato, Masaya; Han, Wei; Saito, Hiroki

2018-06-01

We consider a pseudospin-1/2 Bose-Einstein condensate with Rashba spin-orbit coupling in a two-dimensional toroidal trap. By solving the damped Gross-Pitaevskii equations for this system, we show that the system exhibits a rich variety of stationary states, such as vehicle wheel and flower-petal stripe patterns. These stationary states are stable against perturbation with thermal energy and can survive for a long time. In the presence of rotation, our results show that the rotating systems have exotic vortex configurations. These phenomenon originates from the interplay among spin-orbit coupling, trap geometry, and rotation.

Einstein-Podolsky-Rosen-Bohm experiment and Bell inequality violation using Type 2 parametric down conversion

NASA Technical Reports Server (NTRS)

Kiess, Thomas E.; Shih, Yan-Hua; Sergienko, A. V.; Alley, Carroll O.

1994-01-01

We report a new two-photon polarization correlation experiment for realizing the Einstein-Podolsky-Rosen-Bohm (EPRB) state and for testing Bell-type inequalities. We use the pair of orthogonally-polarized light quanta generated in Type 2 parametric down conversion. Using 1 nm interference filters in front of our detectors, we observe from the output of a 0.5mm beta - BaB2O4 (BBO) crystal the EPRB correlations in coincidence counts, and measure an associated Bell inequality violation of 22 standard deviations. The quantum state of the photon pair is a polarization analog of the spin-1/2 singlet state.

Particle-like solutions of the Einstein-Dirac-Maxwell equations

NASA Astrophysics Data System (ADS)

Finster, Felix; Smoller, Joel; Yau, Shing-Tung

1999-08-01

We consider the coupled Einstein-Dirac-Maxwell equations for a static, spherically symmetric system of two fermions in a singlet spinor state. Soliton-like solutions are constructed numerically. The stability and the properties of the ground state solutions are discussed for different values of the electromagnetic coupling constant. We find solutions even when the electromagnetic coupling is so strong that the total interaction is repulsive in the Newtonian limit. Our solutions are regular and well-behaved; this shows that the combined electromagnetic and gravitational self-interaction of the Dirac particles is finite.

Implementing competency based admissions at the Albert Einstein College of Medicine.

PubMed

Kerrigan, Noreen; Akabas, Myles H; Betzler, Thomas F; Castaldi, Maria; Kelly, Mary S; Levy, Adam S; Reichgott, Michael J; Ruberman, Louise; Dolan, Siobhan M

2016-01-01

The Albert Einstein College of Medicine (Einstein) was founded in 1955 during an era of limited access to medical school for women, racial minorities, and many religious and ethnic groups. Located in the Bronx, NY, Einstein seeks to educate physicians in an environment of state-of-the-art scientific inquiry while simultaneously fulfilling a deep commitment to serve its community by providing the highest quality clinical care. A founding principle of Einstein, the basis upon which Professor Einstein agreed to allow the use of his name, was that admission to the student body would be based entirely on merit. To accomplish this, Einstein has long used a 'holistic' approach to the evaluation of its applicants, actively seeking a diverse student body. More recently, in order to improve its ability to identify students with the potential to be outstanding physicians, who will both advance medical knowledge and serve the pressing health needs of a diverse community, the Committee on Admissions reexamined and restructured the requirements for admission. These have now been categorized as four 'Admissions Competencies' that an applicant must demonstrate. They include: 1) cocurricular activities and relevant experiences; 2) communication skills; 3) personal and professional development; and 4) knowledge. The purpose of this article is to describe the process that resulted in the introduction and implementation of this competency based approach to the admission process.

Spatial entanglement patterns and Einstein-Podolsky-Rosen steering in Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Fadel, Matteo; Zibold, Tilman; Décamps, Boris; Treutlein, Philipp

2018-04-01

Many-particle entanglement is a fundamental concept of quantum physics that still presents conceptual challenges. Although nonclassical states of atomic ensembles were used to enhance measurement precision in quantum metrology, the notion of entanglement in these systems was debated because the correlations among the indistinguishable atoms were witnessed by collective measurements only. Here, we use high-resolution imaging to directly measure the spin correlations between spatially separated parts of a spin-squeezed Bose-Einstein condensate. We observe entanglement that is strong enough for Einstein-Podolsky-Rosen steering: We can predict measurement outcomes for noncommuting observables in one spatial region on the basis of corresponding measurements in another region with an inferred uncertainty product below the Heisenberg uncertainty bound. This method could be exploited for entanglement-enhanced imaging of electromagnetic field distributions and quantum information tasks.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1975-07-01

This illustration is a schematic of the High Energy Astronomy Observatory (HEAO)-2 and its experiments. It shows the focal plane instruments (at the right) plus the associated electronics for operating the telescope as it transmitted its observations to the ground. A fifth instrument, the Monitor Proportional Counter, is located near the front of the telescope. Four separate astronomical instruments are located at the focus of this telescope and they could be interchanged for different types of observations as the observatory pointed at interesting areas of the Sky. Two of these instruments produced images; a High Resolution Imaging Detector and an Imaging Proportional Counter. The other two instruments, the Solid State Spectrometer and the Crystal Spectrometer, measured the spectra of x-ray objects. A fifth instrument, the Monitor Proportional Counter, continuously viewed space independently to study a wider band of x-ray wavelengths and to examine the rapid time variations in the sources. The HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978. The HEAO-2 was originally identified as HEAO-B but the designation was changed once the spacecraft achieved orbit.

Enhanced factoring with a bose-einstein condensate.

PubMed

Sadgrove, Mark; Kumar, Sanjay; Nakagawa, Ken'ichi

2008-10-31

We present a novel method to realize analog sum computation with a Bose-Einstein condensate in an optical lattice potential subject to controlled phase jumps. We use the method to implement the Gauss sum algorithm for factoring numbers. By exploiting higher order quantum momentum states, we are able to improve the algorithm's accuracy beyond the limits of the usual classical implementation.

On the Einstein-Podolsky-Rosen Paradox

NASA Astrophysics Data System (ADS)

McWeeny, Roy

Central to the EPR paradox is a [`]thought experiment' in which two spins are initially coupled to a state with S = 0 and are then separated to a large distance, at which they can be separately observed. Quantum mechanics apparently predicts that the two spins remain forever coupled, but this conflicts with Einstein's principle of [`]locality' or [`]separability', according to which spatially well separated systems must be independent, no matter how strongly they have interacted in the past. It is now widely held that Einstein was wrong and that [`]non-locality' follows inevitably from quantum mechanics i.e. that even distant systems are never truly separable.

Static Einstein-Maxwell Black Holes with No Spatial Isometries in AdS Space.

PubMed

Herdeiro, Carlos A R; Radu, Eugen

2016-11-25

We explicitly construct static black hole solutions to the fully nonlinear, D=4, Einstein-Maxwell-anti-de Sitter (AdS) equations that have no continuous spatial symmetries. These black holes have a smooth, topologically spherical horizon (section), but without isometries, and approach, asymptotically, global AdS spacetime. They are interpreted as bound states of a horizon with the Einstein-Maxwell-AdS solitons recently discovered, for appropriate boundary data. In sharp contrast to the uniqueness results for a Minkowski electrovacuum, the existence of these black holes shows that single, equilibrium, black hole solutions in an AdS electrovacuum admit an arbitrary multipole structure.

Satisfying the Einstein-Podolsky-Rosen criterion with massive particles

NASA Astrophysics Data System (ADS)

Peise, J.; Kruse, I.; Lange, K.; Lücke, B.; Pezzè, L.; Arlt, J.; Ertmer, W.; Hammerer, K.; Santos, L.; Smerzi, A.; Klempt, C.

2016-03-01

In 1935, Einstein, Podolsky and Rosen (EPR) questioned the completeness of quantum mechanics by devising a quantum state of two massive particles with maximally correlated space and momentum coordinates. The EPR criterion qualifies such continuous-variable entangled states, as shown successfully with light fields. Here, we report on the production of massive particles which meet the EPR criterion for continuous phase/amplitude variables. The created quantum state of ultracold atoms shows an EPR parameter of 0.18(3), which is 2.4 standard deviations below the threshold of 1/4. Our state presents a resource for tests of quantum nonlocality with massive particles and a wide variety of applications in the field of continuous-variable quantum information and metrology.

Entropy of the Bose-Einstein-condensate ground state: Correlation versus ground-state entropy

NASA Astrophysics Data System (ADS)

Kim, Moochan B.; Svidzinsky, Anatoly; Agarwal, Girish S.; Scully, Marlan O.

2018-01-01

Calculation of the entropy of an ideal Bose-Einstein condensate (BEC) in a three-dimensional trap reveals unusual, previously unrecognized, features of the canonical ensemble. It is found that, for any temperature, the entropy of the Bose gas is equal to the entropy of the excited particles although the entropy of the particles in the ground state is nonzero. We explain this by considering the correlations between the ground-state particles and particles in the excited states. These correlations lead to a correlation entropy which is exactly equal to the contribution from the ground state. The correlations themselves arise from the fact that we have a fixed number of particles obeying quantum statistics. We present results for correlation functions between the ground and excited states in a Bose gas, so as to clarify the role of fluctuations in the system. We also report the sub-Poissonian nature of the ground-state fluctuations.

Modified Einstein and Navier-Stokes Equations

NASA Astrophysics Data System (ADS)

Bulyzhenkov, I. É.

2018-05-01

The appearance of inertial rest mass-energy is associated with the kinematic slowing-down of time and with the vortex state of the elementary massive space with zero integral of its kinetic and potential energies. An analog of the Einstein equation is found for moving densities of a non-empty metric space in the concept of the Einstein-Infeld material field. The vector consequences of this tensor equation for a metric medium of overlapping elementary carriers of continuous mass-energies allow us to modify the Navier-Stokes equation under inertial motion of the matter of the nonlocal field in the nonrelativistic limit. The nonlocality of massenergy generates kinematic accelerations of feedback to Newtonian acceleration, which impedes asymptotic divergence of energy fluxes. Stabilization of inertial media by dynamic Bernoulli pressure corresponds to nonlocal self-organization of Einstein-Infeld non-empty space and invalidates Newtonian localization of masses in empty space.

Modified Einstein and Navier–Stokes Equations

NASA Astrophysics Data System (ADS)

Bulyzhenkov, I. É.

2018-05-01

The appearance of inertial rest mass-energy is associated with the kinematic slowing-down of time and with the vortex state of the elementary massive space with zero integral of its kinetic and potential energies. An analog of the Einstein equation is found for moving densities of a non-empty metric space in the concept of the Einstein-Infeld material field. The vector consequences of this tensor equation for a metric medium of overlapping elementary carriers of continuous mass-energies allow us to modify the Navier-Stokes equation under inertial motion of the matter of the nonlocal field in the nonrelativistic limit. The nonlocality of massenergy generates kinematic accelerations of feedback to Newtonian acceleration, which impedes asymptotic divergence of energy fluxes. Stabilization of inertial media by dynamic Bernoulli pressure corresponds to nonlocal self-organization of Einstein-Infeld non-empty space and invalidates Newtonian localization of masses in empty space.

Low temperature heat capacities and thermodynamic functions described by Debye-Einstein integrals.

PubMed

Gamsjäger, Ernst; Wiessner, Manfred

2018-01-01

Thermodynamic data of various crystalline solids are assessed from low temperature heat capacity measurements, i.e., from almost absolute zero to 300 K by means of semi-empirical models. Previous studies frequently present fit functions with a large amount of coefficients resulting in almost perfect agreement with experimental data. It is, however, pointed out in this work that special care is required to avoid overfitting. Apart from anomalies like phase transformations, it is likely that data from calorimetric measurements can be fitted by a relatively simple Debye-Einstein integral with sufficient precision. Thereby, reliable values for the heat capacities, standard enthalpies, and standard entropies at T  = 298.15 K are obtained. Standard thermodynamic functions of various compounds strongly differing in the number of atoms in the formula unit can be derived from this fitting procedure and are compared to the results of previous fitting procedures. The residuals are of course larger when the Debye-Einstein integral is applied instead of using a high number of fit coefficients or connected splines, but the semi-empiric fit coefficients keep their meaning with respect to physics. It is suggested to use the Debye-Einstein integral fit as a standard method to describe heat capacities in the range between 0 and 300 K so that the derived thermodynamic functions are obtained on the same theory-related semi-empiric basis. Additional fitting is recommended when a precise description for data at ultra-low temperatures (0-20 K) is requested.

Collective multipartite Einstein-Podolsky-Rosen steering: more secure optical networks.

PubMed

Wang, Meng; Gong, Qihuang; He, Qiongyi

2014-12-01

Collective multipartite Einstein-Podolsky-Rosen (EPR) steering is a type of quantum correlation shared among N parties, where the EPR paradox of one party can only be realized by performing local measurements on all the remaining N-1 parties. We formalize the collective tripartite steering in terms of local hidden state model and give the steering inequalities that act as signatures and suggest how to optimize collective tripartite steering in specific optical schemes. The special entangled states with property of collective multipartite steering may have potential applications in ultra-secure multiuser communication networks where the issue of trust is critical.

Growth or decay of cosmological inhomogeneities as a function of their equation of state

NASA Astrophysics Data System (ADS)

Comer, G. L.; Deruelle, Nathalie; Langlois, David; Parry, Joe

1994-03-01

We expand Einstein's equations in the synchronous gauge in terms of a purely space-dependent, ``seed,'' metric. The (nonlinear) solution accurately describes a universe inhomogeneous at scales larger than the Hubble radius. We show that the inhomogeneities grow or decay, as time increases, depending on the equation of state for the matter (supposed to be a perfect fluid). We then consider the case when matter is a scalar field with an arbitrary potential. Finally we discuss the generality of the model and show that it is an attractor for a class of generic solutions of Einstein's equations.

Cooling of a Bose-Einstein Condensate by Spin Distillation.

PubMed

Naylor, B; Maréchal, E; Huckans, J; Gorceix, O; Pedri, P; Vernac, L; Laburthe-Tolra, B

2015-12-11

We propose and experimentally demonstrate a new cooling mechanism leading to purification of a Bose-Einstein condensate (BEC). Our scheme starts with a BEC polarized in the lowest energy spin state. Spin excited states are thermally populated by lowering the single particle energy gap set by the magnetic field. Then, these spin-excited thermal components are filtered out, which leads to an increase of the BEC fraction. We experimentally demonstrate such cooling for a spin 3 ^{52}Cr dipolar BEC. Our scheme should be applicable to Na or Rb, with the perspective to reach temperatures below 1 nK.

Leggett-Garg tests of macrorealism for bosonic systems including double-well Bose-Einstein condensates and atom interferometers

NASA Astrophysics Data System (ADS)

Rosales-Zárate, L.; Opanchuk, B.; He, Q. Y.; Reid, M. D.

2018-04-01

We construct quantifiable generalizations of Leggett-Garg tests for macro- and mesoscopic realism and noninvasive measurability that apply when not all outcomes of measurement can be identified as arising from one of two macroscopically distinguishable states. We show how quantum mechanics predicts a negation of the Leggett-Garg premises for strategies involving ideal negative-result, weak, and minimally invasive ("nonclumsy") projective measurements on dynamical entangled systems, as might be realized with Bose-Einstein condensates in a double-well potential, path-entangled NOON states, and atom interferometers. Potential loopholes associated with each strategy are discussed.

Scalar field as a Bose-Einstein condensate?

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

Castellanos, Elías; Escamilla-Rivera, Celia; Macías, Alfredo

We discuss the analogy between a classical scalar field with a self-interacting potential, in a curved spacetime described by a quasi-bounded state, and a trapped Bose-Einstein condensate. In this context, we compare the Klein-Gordon equation with the Gross-Pitaevskii equation. Moreover, the introduction of a curved background spacetime endows, in a natural way, an equivalence to the Gross-Pitaevskii equation with an explicit confinement potential. The curvature also induces a position dependent self-interaction parameter. We exploit this analogy by means of the Thomas-Fermi approximation, commonly used to describe the Bose-Einstein condensate, in order to analyze the quasi bound scalar field distribution surroundingmore » a black hole.« less

Strong Einstein-Podolsky-Rosen steering with unconditional entangled states

NASA Astrophysics Data System (ADS)

Steinlechner, Sebastian; Bauchrowitz, Jöran; Eberle, Tobias; Schnabel, Roman

2013-02-01

In 1935 Schrödinger introduced the terms entanglement and steering in the context of the famous gedanken experiment discussed by Einstein, Podolsky, and Rosen (EPR). Here, we report on a sixfold increase of the observed EPR-steering effect with regard to previous experiments, as quantified by the Reid criterion. We achieved an unprecedented low conditional variance product of about 0.04<1, where 1 is the upper bound below which steering is demonstrated. The steering effect was observed on an unconditional two-mode-squeezed entangled state that contained a total vacuum state contribution of less than 8%, including detection imperfections. Together with the achieved high interference contrast between the entangled state and a bright coherent laser field, our state is compatible with efficient applications in high-power laser interferometers and fiber-based networks for entanglement distribution.

Was Einstein Really a Pacifist? Einstein's Independent, Forward-Thinking, Flexible, and Self-Defined Pacifism

NASA Astrophysics Data System (ADS)

Holmes, Virginia Iris

2005-03-01

Perhaps motivated by an admiration for Einstein and a desire to identify with him, combined with a majority world-view in opposition to pacifism, skeptics may often question whether Einstein was really a pacifist. They might point to the fact that his dramatic contributions to the field of physics at the beginning of the twentieth century made nuclear weapons possible, as well as his 1939 letter to President Franklin D. Roosevelt urging him to develop such weapons before the Nazis would, as examples of at least an inconsistent stance on pacifism across time on Einstein's part. However, as this paper will show, Einstein's pacifism began early in his life, was a deep-seated conviction that he expressed repeatedly across the years, and was an independent pacifism that flowed from his own responses to events around him and contained some original and impressively forward-thinking elements. Moreover, in calling himself a pacifist, as Einstein did, he defined pacifism in his own terms, not according to the standards of others, and this self-defined pacifism included the flexibility to designate the Nazis as a special case that had to be opposed through the use of military violence, in his view. As early as during his childhood, Einstein already disliked competitive games, because of the necessity of winners and losers, and disliked military discipline. In his late thirties, living in Germany during the First World War with a prestigious academic position in Berlin, yet retaining his identity as a Swiss citizen, Einstein joined a small group of four intellectuals who signed the pacifist ``Appeal to the Europeans'' in response to the militarist ``Manifesto to the Civilized World'' signed by 93 German intellectuals. In private, throughout that War, Einstein repeatedly expressed his disgust and sense of alienation at the ``war-enthusiasm'' sentiment of the majority. In the aftermath of the War, Einstein was involved in a German private commission to investigate German war crimes and the publication that it produced, and throughout the Weimar period of 1918 to 1933 Einstein continued to take public and private stances as a pacifist. As did many pacifists, Einstein also linked his advocacy for peace with a concern for social justice, which included opposition to antisemitism and advocacy for Zionism, and in 1929, after violent clashes between Jews and Arabs in Palestine, in which hundreds died on both sides, Einstein made some impressively forward-thinking statements about Jewish-Arab conciliation, and even published in an Arab newspaper his own proposal to set up a joint Jewish-Arab council for purposes of conflict resolution. But Einstein's pacifism was not forever obliterated by the Nazi era and the Holocaust, despite his well-known encouragement to Roosevelt to develop the bomb. In the United States, where he lived from 1933 on, in the first ten years after World War II, also the last decade of his life, Einstein inspired American pacifists with his strong stances against war and nuclear weapons.

Thermodynamics of a Higher Dimensional Noncommutative Inspired Anti-de Sitter-Einstein-Born-Infeld Black Hole

NASA Astrophysics Data System (ADS)

González, Angélica; Linares, Román; Maceda, Marco; Sánchez-Santos, Oscar

2018-04-01

We analyze noncommutative deformations of a higher dimensional anti-de Sitter-Einstein-Born-Infeld black hole. Two models based on noncommutative inspired distributions of mass and charge are discussed and their thermodynamical properties such as the equation of state are explicitly calculated. In the (3 + 1)-dimensional case the Gibbs energy function of each model is used to discuss the presence of phase transitions.

Local structure of solid Rb at megabar pressures

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

De Panfilis, S.; Gorelli, F.; Santoro, M.

2015-06-07

We have investigated the local and electronic structure of solid rubidium by means of x-ray absorption spectroscopy up to 101.0 GPa, thus doubling the maximum investigated experimental pressure. This study confirms the predicted stability of phase VI and was completed by the combination of two pivotal instrumental solutions. On one side, we made use of nanocrystalline diamond anvils, which, contrary to the more commonly used single crystal diamond anvils, do not generate sharp Bragg peaks (glitches) at specific energies that spoil the weak fine structure oscillations in the x-ray absorption cross section. Second, we exploited the performance of a state-of-the-artmore » x-ray focussing device yielding a beam spot size of 5 × 5 μm{sup 2}, spatially stable over the entire energy scan. An advanced data analysis protocol was implemented to extract the pressure dependence of the structural parameters in phase VI of solid Rb from 51.2 GPa up to the highest pressure. A continuous reduction of the nearest neighbour distances was observed, reaching about 6% over the probed pressure range. We also discuss a phenomenological model based on the Einstein approximation to describe the pressure behaviour of the mean-square relative displacement. Within this simplified scheme, we estimate the Grüneisen parameter for this high pressure Rb phase to be in the 1.3–1.5 interval.« less

Exact ground-state correlation functions of an atomic-molecular Bose–Einstein condensate model

NASA Astrophysics Data System (ADS)

Links, Jon; Shen, Yibing

2018-05-01

We study the ground-state properties of an atomic-molecular Bose–Einstein condensate model through an exact Bethe Ansatz solution. For a certain range of parameter choices, we prove that the ground-state Bethe roots lie on the positive real-axis. We then use a continuum limit approach to obtain a singular integral equation characterising the distribution of these Bethe roots. Solving this equation leads to an analytic expression for the ground-state energy. The form of the expression is consistent with the existence of a line of quantum phase transitions, which has been identified in earlier studies. This line demarcates a molecular phase from a mixed phase. Certain correlation functions, which characterise these phases, are then obtained through the Hellmann–Feynman theorem.

Phase transition kinetics for a Bose Einstein condensate in a periodically driven band system

NASA Astrophysics Data System (ADS)

Michon, E.; Cabrera-Gutiérrez, C.; Fortun, A.; Berger, M.; Arnal, M.; Brunaud, V.; Billy, J.; Petitjean, C.; Schlagheck, P.; Guéry-Odelin, D.

2018-05-01

The dynamical transition of an atomic Bose–Einstein condensate from a spatially periodic state to a staggered state with alternating sign in its wavefunction is experimentally studied using a one-dimensional phase modulated optical lattice. We observe the crossover from quantum to thermal fluctuations as the triggering mechanism for the nucleation of staggered states. In good quantitative agreement with numerical simulations based on the truncated Wigner method, we experimentally investigate how the nucleation time varies with the renormalized tunneling rate, the atomic density, and the driving frequency. The effective inverted energy band in the driven lattice is identified as the key ingredient which explains the emergence of gap solitons as observed in numerics and the possibility to nucleate staggered states from interband excitations as reported experimentally.

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.

2011 Einstein Fellows Chosen

NASA Astrophysics Data System (ADS)

2011-03-01

ASA has announced the selection of the 2011 Einstein Fellows who will conduct research related to NASA's Physics of the Cosmos program, which aims to expand our knowledge of the origin, evolution, and fate of the Universe. The Einstein Fellowship provides support to the awardees for three years, and the Fellows may pursue their research at a host university or research center of their choosing in the United States. The new Fellows will begin their programs in the fall of 2011. The new Einstein Fellows and their host institutions are listed below: * Akos Bogdan (Smithsonian Astrophysical Observatory, Cambridge, Mass.) * Samuel Gralla (University of Maryland, College Park, Md.) * Philip Hopkins (University of California at Berkeley) * Matthew Kunz (Princeton University, Princeton, N.J.) * Laura Lopez (Massachusetts Institute of Technology, Cambridge, Mass.) * Amy Reines (National Radio Astronomy Observatory, Charlottesville, Virg.) * Rubens Reis (University of Michigan, Ann Arbor) * Ken Shen (Lawrence Berkeley National Laboratory, Berkeley, Calif.) * Jennifer Siegal-Gaskins (California Institute of Technology, Pasadena) * Lorenzo Sironi (Harvard University, Cambridge, Mass.) NASA has two other astrophysics theme-based fellowship programs: the Sagan Fellowship Program, which supports research into exoplanet exploration, and the Hubble Fellowship Program, which supports research into cosmic origins. More information on the Einstein Fellowships can be found at: http://cxc.harvard.edu/fellows/

Bell’s Nonlocality Can be Detected by the Violation of Einstein-Podolsky-Rosen Steering Inequality

PubMed Central

Chen, Jing-Ling; Ren, Changliang; Chen, Changbo; Ye, Xiang-Jun; Pati, Arun Kumar

2016-01-01

Recently quantum nonlocality has been classified into three distinct types: quantum entanglement, Einstein-Podolsky-Rosen steering, and Bell’s nonlocality. Among which, Bell’s nonlocality is the strongest type. Bell’s nonlocality for quantum states is usually detected by violation of some Bell’s inequalities, such as Clause-Horne-Shimony-Holt inequality for two qubits. Steering is a manifestation of nonlocality intermediate between entanglement and Bell’s nonlocality. This peculiar feature has led to a curious quantum phenomenon, the one-way Einstein-Podolsky-Rosen steering. The one-way steering was an important open question presented in 2007, and positively answered in 2014 by Bowles et al., who presented a simple class of one-way steerable states in a two-qubit system with at least thirteen projective measurements. The inspiring result for the first time theoretically confirms quantum nonlocality can be fundamentally asymmetric. Here, we propose another curious quantum phenomenon: Bell nonlocal states can be constructed from some steerable states. This novel finding not only offers a distinctive way to study Bell’s nonlocality without Bell’s inequality but with steering inequality, but also may avoid locality loophole in Bell’s tests and make Bell’s nonlocality easier for demonstration. Furthermore, a nine-setting steering inequality has also been presented for developing more efficient one-way steering and detecting some Bell nonlocal states. PMID:27966616

Disorder in Protein Crystals.

NASA Astrophysics Data System (ADS)

Clarage, James Braun, II

1990-01-01

Methods have been developed for analyzing the diffuse x-ray scattering in the halos about a crystal's Bragg reflections as a means of determining correlations in atomic displacements in protein crystals. The diffuse intensity distribution for rhombohedral insulin, tetragonal lysozyme, and triclinic lysozyme crystals was best simulated in terms of exponential displacement correlation functions. About 90% of the disorder can be accounted for by internal movements correlated with a decay distance of about 6A; the remaining 10% corresponds to intermolecular movements that decay in a distance the order of size of the protein molecule. The results demonstrate that protein crystals fit into neither the Einstein nor the Debye paradigms for thermally fluctuating crystalline solids. Unlike the Einstein model, there are correlations in the atomic displacements, but these correlations decay more steeply with distance than predicted by the Debye-Waller model for an elastic solid. The observed displacement correlations are liquid -like in the sense that they decay exponentially with the distance between atoms, just as positional correlations in a liquid. This liquid-like disorder is similar to the disorder observed in 2-D crystals of polystyrene latex spheres, and similar systems where repulsive interactions dominate; hence, these colloidal crystals appear to provide a better analogy for the dynamics of protein crystals than perfectly elastic lattices.

Position and Momentum Entanglement of Dipole-Dipole Interacting Atoms in Optical Lattices

NASA Astrophysics Data System (ADS)

Opatrný, T.; Kolář, M.; Kurizki, G.

We consider a possible realization of the position- and momentum-correlated atomic pairs that are confined to adjacent sites of two mutually shifted optical lattices and are entangled via laser-induced dipole-dipole interactions. The Einstein-Podolsky-Rosen (EPR) "paradox" [Einstein 1935] with translational variables is then modified by lattice-diffraction effects. We study a possible mechanism of creating such diatom entangled states by varying the effective mass of the atoms.

Sonic analog of gravitational black holes in bose-einstein condensates

PubMed

Garay; Anglin; Cirac; Zoller

2000-11-27

It is shown that, in dilute-gas Bose-Einstein condensates, there exist both dynamically stable and unstable configurations which, in the hydrodynamic limit, exhibit a behavior resembling that of gravitational black holes. The dynamical instabilities involve creation of quasiparticle pairs in positive and negative energy states, as in the well-known suggested mechanism for black-hole evaporation. We propose a scheme to generate a stable sonic black hole in a ring trap.

Bose-Einstein condensation and independent production of pions

NASA Astrophysics Data System (ADS)

Bialas, A.; Zalewski, K.

1998-09-01

The influence of the HBT effect on the momentum spectra of independently produced pions is studied using the method developed earlier for discussion of multiplicity distributions. It is shown that in this case all the spectra and multiparticle correlation functions are expressible in terms of one function of two momenta. It is also shown that at the critical point all pions are attracted into one quantum state and thus form a Bose-Einstein condensate.

Bose-Einstein condensation in the relativistic ideal Bose gas.

PubMed

Grether, M; de Llano, M; Baker, George A

2007-11-16

The Bose-Einstein condensation (BEC) critical temperature in a relativistic ideal Bose gas of identical bosons, with and without the antibosons expected to be pair-produced abundantly at sufficiently hot temperatures, is exactly calculated for all boson number densities, all boson point rest masses, and all temperatures. The Helmholtz free energy at the critical BEC temperature is lower with antibosons, thus implying that omitting antibosons always leads to the computation of a metastable state.

Collision of impurities with Bose–Einstein condensates

NASA Astrophysics Data System (ADS)

Lingua, F.; Lepori, L.; Minardi, F.; Penna, V.; Salasnich, L.

2018-04-01

Quantum dynamics of impurities in a bath of bosons is a long-standing problem in solid-state, plasma, and atomic physics. Recent experimental and theoretical investigations with ultracold atoms have focused on this problem, studying atomic impurities immersed in an atomic Bose–Einstein condensate (BEC) and for various relative coupling strengths tuned by the Fano‑Feshbach resonance technique. Here, we report extensive numerical simulations on a closely related problem: the collision between a bosonic impurity consisting of a few 41K atoms and a BEC of 87Rb atoms in a quasi one-dimensional configuration and under a weak harmonic axial confinement. For small values of the inter-species interaction strength (regardless of its sign), we find that the impurity, which starts from outside the BEC, simply causes the BEC cloud to oscillate back and forth, but the frequency of oscillation depends on the interaction strength. For intermediate couplings, after a few cycles of oscillation the impurity is captured by the BEC, and strongly changes its amplitude of oscillation. In the strong interaction regime, if the inter-species interaction is attractive, a local maximum (bright soliton) in the BEC density occurs where the impurity is trapped; if, instead, the inter-species interaction is repulsive, the impurity is not able to enter the BEC cloud and the reflection coefficient is close to one. However, if the initial displacement of the impurity is increased, the impurity is able to penetrate the cloud, leading to the appearance of a moving hole (dark soliton) in the BEC.

High Energy Astronomy Observatory (HEAO)-2

NASA Technical Reports Server (NTRS)

1975-01-01

This illustration is a schematic of the High Energy Astronomy Observatory (HEAO)-2 and its experiments. It shows the focal plane instruments (at the right) plus the associated electronics for operating the telescope as it transmitted its observations to the ground. A fifth instrument, the Monitor Proportional Counter, is located near the front of the telescope. Four separate astronomical instruments are located at the focus of this telescope and they could be interchanged for different types of observations as the observatory pointed at interesting areas of the Sky. Two of these instruments produced images; a High Resolution Imaging Detector and an Imaging Proportional Counter. The other two instruments, the Solid State Spectrometer and the Crystal Spectrometer, measured the spectra of x-ray objects. A fifth instrument, the Monitor Proportional Counter, continuously viewed space independently to study a wider band of x-ray wavelengths and to examine the rapid time variations in the sources. The HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978. The HEAO-2 was originally identified as HEAO-B but the designation was changed once the spacecraft achieved orbit.

Communication: Visible line intensities of the triatomic hydrogen ion from experiment and theory

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

Petrignani, Annemieke; Berg, Max H.; Grussie, Florian

2014-12-28

The visible spectrum of H{sub 3}{sup +} is studied using high-sensitivity action spectroscopy in a cryogenic radiofrequency multipole trap. Advances are made to measure the weak ro-vibrational transitions from the lowest rotational states of H{sub 3}{sup +} up to high excitation energies providing visible line intensities and, after normalisation to an infrared calibration line, the corresponding Einstein B coefficients. Ab initio predictions for the Einstein B coefficients are obtained from a highly precise dipole moment surface of H{sub 3}{sup +} and found to be in excellent agreement, even in the region where states have been classified as chaotic.

Correlations of occupation numbers in the canonical ensemble and application to a Bose-Einstein condensate in a one-dimensional harmonic trap

NASA Astrophysics Data System (ADS)

Giraud, Olivier; Grabsch, Aurélien; Texier, Christophe

2018-05-01

We study statistical properties of N noninteracting identical bosons or fermions in the canonical ensemble. We derive several general representations for the p -point correlation function of occupation numbers n1⋯np ¯. We demonstrate that it can be expressed as a ratio of two p ×p determinants involving the (canonical) mean occupations n1¯, ..., np¯, which can themselves be conveniently expressed in terms of the k -body partition functions (with k ≤N ). We draw some connection with the theory of symmetric functions and obtain an expression of the correlation function in terms of Schur functions. Our findings are illustrated by revisiting the problem of Bose-Einstein condensation in a one-dimensional harmonic trap, for which we get analytical results. We get the moments of the occupation numbers and the correlation between ground-state and excited-state occupancies. In the temperature regime dominated by quantum correlations, the distribution of the ground-state occupancy is shown to be a truncated Gumbel law. The Gumbel law, describing extreme-value statistics, is obtained when the temperature is much smaller than the Bose-Einstein temperature.

FIRST Quantum-(1980)-Computing DISCOVERY in Siegel-Rosen-Feynman-...A.-I. Neural-Networks: Artificial(ANN)/Biological(BNN) and Siegel FIRST Semantic-Web and Siegel FIRST ``Page''-``Brin'' ``PageRank'' PRE-Google Search-Engines!!!

NASA Astrophysics Data System (ADS)

Rosen, Charles; Siegel, Edward Carl-Ludwig; Feynman, Richard; Wunderman, Irwin; Smith, Adolph; Marinov, Vesco; Goldman, Jacob; Brine, Sergey; Poge, Larry; Schmidt, Erich; Young, Frederic; Goates-Bulmer, William-Steven; Lewis-Tsurakov-Altshuler, Thomas-Valerie-Genot; Ibm/Exxon Collaboration; Google/Uw Collaboration; Microsoft/Amazon Collaboration; Oracle/Sun Collaboration; Ostp/Dod/Dia/Nsa/W.-F./Boa/Ubs/Ub Collaboration

2013-03-01

Belew[Finding Out About, Cambridge(2000)] and separately full-decade pre-Page/Brin/Google FIRST Siegel-Rosen(Machine-Intelligence/Atherton)-Feynman-Smith-Marinov(Guzik Enterprises/Exxon-Enterprises/A.-I./Santa Clara)-Wunderman(H.-P.) [IBM Conf. on Computers and Mathematics, Stanford(1986); APS Mtgs.(1980s): Palo Alto/Santa Clara/San Francisco/...(1980s) MRS Spring-Mtgs.(1980s): Palo Alto/San Jose/San Francisco/...(1980-1992) FIRST quantum-computing via Bose-Einstein quantum-statistics(BEQS) Bose-Einstein CONDENSATION (BEC) in artificial-intelligence(A-I) artificial neural-networks(A-N-N) and biological neural-networks(B-N-N) and Siegel[J. Noncrystalline-Solids 40, 453(1980); Symp. on Fractals..., MRS Fall-Mtg., Boston(1989)-5-papers; Symp. on Scaling..., (1990); Symp. on Transport in Geometric-Constraint (1990)

Gravity Probe B: Testing Einstein with Gyroscopes

NASA Technical Reports Server (NTRS)

Geveden, Rex D.; May, Todd

2003-01-01

Some 40 years in the making, NASA' s historic Gravity Probe B (GP-B) mission is scheduled to launch aboard a Delta II in 2003. GP-B will test two extraordinary predictions from Einstein's General Relativity: geodetic precession and the Lense-Thirring effect (frame-dragging). Employing tiny, ultra-precise gyroscopes, GP-B features a measurement accuracy of 0.5 milli-arc-seconds per year. The extraordinary measurement precision is made possible by a host of breakthrough technologies, including electro-statically suspended, super-conducting quartz gyroscopes; virtual elimination of magnetic flux; a solid quartz star tracking telescope; helium microthrusters for drag-free control of the spacecraft; and a 2400 liter superfluid helium dewar. This paper will provide an overview of the science, key technologies, flight hardware, integration and test, and flight operations of the GP-B space vehicle. It will also examine some of the technical management challenges of a large-scale, technology-driven, Principal Investigator-led mission.

Gravity Probe B: Testing Einstein with Gyroscopes

NASA Technical Reports Server (NTRS)

Geveden, Rex D.; May, Todd

2003-01-01

Some 40 years in the making, NASA s historic Gravity Probe B (GP-B) mission is scheduled to launch aboard a Delta I1 in 2003. GP-B will test two extraordinary predictions from Einstein s General Relativity: geodetic precession and the Lense-Thirring effect (frame-dragging). Employing tiny, ultra-precise gyroscopes, GP-B features a measurement accuracy of 0.5 milli-arc-seconds per year. The extraordinary measurement precision is made possible by a host of breakthrough technologies, including electro-statically suspended, super-conducting quartz gyroscopes; virtual elimination of magnetic flux; a solid quartz star- tracking telescope; helium microthrusters for drag-free control of the spacecraft; and a 2400 liter superfluid helium dewar. This paper will provide an overview of the science, key technologies, flight hardware, integration and test, and flight operations of the GP-B space vehicle. It will also examine some of the technical management challenges of a large-scale, technology-driven, Principal Investigator-led mission.

Spatial entanglement patterns and Einstein-Podolsky-Rosen steering in Bose-Einstein condensates.

PubMed

Fadel, Matteo; Zibold, Tilman; Décamps, Boris; Treutlein, Philipp

2018-04-27

Many-particle entanglement is a fundamental concept of quantum physics that still presents conceptual challenges. Although nonclassical states of atomic ensembles were used to enhance measurement precision in quantum metrology, the notion of entanglement in these systems was debated because the correlations among the indistinguishable atoms were witnessed by collective measurements only. Here, we use high-resolution imaging to directly measure the spin correlations between spatially separated parts of a spin-squeezed Bose-Einstein condensate. We observe entanglement that is strong enough for Einstein-Podolsky-Rosen steering: We can predict measurement outcomes for noncommuting observables in one spatial region on the basis of corresponding measurements in another region with an inferred uncertainty product below the Heisenberg uncertainty bound. This method could be exploited for entanglement-enhanced imaging of electromagnetic field distributions and quantum information tasks. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Simplified methods for computing total sediment discharge with the modified Einstein procedure

USGS Publications Warehouse

Colby, Bruce R.; Hubbell, David Wellington

1961-01-01

A procedure was presented in 1950 by H. A. Einstein for computing the total discharge of sediment particles of sizes that are in appreciable quantities in the stream bed. This procedure was modified by the U.S. Geological Survey and adapted to computing the total sediment discharge of a stream on the basis of samples of bed sediment, depth-integrated samples of suspended sediment, streamflow measurements, and water temperature. This paper gives simplified methods for computing total sediment discharge by the modified Einstein procedure. Each of four homographs appreciably simplifies a major step in the computations. Within the stated limitations, use of the homographs introduces much less error than is present in either the basic data or the theories on which the computations of total sediment discharge are based. The results are nearly as accurate mathematically as those that could be obtained from the longer and more complex arithmetic and algebraic computations of the Einstein procedure.

Particlelike solutions of the Einstein-Dirac equations

NASA Astrophysics Data System (ADS)

Finster, Felix; Smoller, Joel; Yau, Shing-Tung

1999-05-01

The coupled Einstein-Dirac equations for a static, spherically symmetric system of two fermions in a singlet spinor state are derived. Using numerical methods, we construct an infinite number of solitonlike solutions of these equations. The stability of the solutions is analyzed. For weak coupling (i.e., small rest mass of the fermions), all the solutions are linearly stable (with respect to spherically symmetric perturbations), whereas for stronger coupling, both stable and unstable solutions exist. For the physical interpretation, we discuss how the energy of the fermions and the (ADM) mass behave as functions of the rest mass of the fermions. Although gravitation is not renormalizable, our solutions of the Einstein-Dirac equations are regular and well behaved even for strong coupling.

Stability of Einstein static universe in gravity theory with a non-minimal derivative coupling

NASA Astrophysics Data System (ADS)

Huang, Qihong; Wu, Puxun; Yu, Hongwei

2018-01-01

The emergent mechanism provides a possible way to resolve the big-bang singularity problem by assuming that our universe originates from the Einstein static (ES) state. Thus, the existence of a stable ES solution becomes a very crucial prerequisite for the emergent scenario. In this paper, we study the stability of an ES universe in gravity theory with a non-minimal coupling between the kinetic term of a scalar field and the Einstein tensor. We find that the ES solution is stable under both scalar and tensor perturbations when the model parameters satisfy certain conditions, which indicates that the big-bang singularity can be avoided successfully by the emergent mechanism in the non-minimally kinetic coupled gravity.

Gauss Seidel-type methods for energy states of a multi-component Bose Einstein condensate

NASA Astrophysics Data System (ADS)

Chang, Shu-Ming; Lin, Wen-Wei; Shieh, Shih-Feng

2005-01-01

In this paper, we propose two iterative methods, a Jacobi-type iteration (JI) and a Gauss-Seidel-type iteration (GSI), for the computation of energy states of the time-independent vector Gross-Pitaevskii equation (VGPE) which describes a multi-component Bose-Einstein condensate (BEC). A discretization of the VGPE leads to a nonlinear algebraic eigenvalue problem (NAEP). We prove that the GSI method converges locally and linearly to a solution of the NAEP if and only if the associated minimized energy functional problem has a strictly local minimum. The GSI method can thus be used to compute ground states and positive bound states, as well as the corresponding energies of a multi-component BEC. Numerical experience shows that the GSI converges much faster than JI and converges globally within 10-20 steps.

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

Many-body interferometry of magnetic polaron dynamics

NASA Astrophysics Data System (ADS)

Ashida, Yuto; Schmidt, Richard; Tarruell, Leticia; Demler, Eugene

2018-02-01

The physics of quantum impurities coupled to a many-body environment is among the most important paradigms of condensed-matter physics. In particular, the formation of polarons, quasiparticles dressed by the polarization cloud, is key to the understanding of transport, optical response, and induced interactions in a variety of materials. Despite recent remarkable developments in ultracold atoms and solid-state materials, the direct measurement of their ultimate building block, the polaron cloud, has remained a fundamental challenge. We propose and analyze a platform to probe time-resolved dynamics of polaron-cloud formation with an interferometric protocol. We consider an impurity atom immersed in a two-component Bose-Einstein condensate where the impurity generates spin-wave excitations that can be directly measured by the Ramsey interference of surrounding atoms. The dressing by spin waves leads to the formation of magnetic polarons and reveals a unique interplay between few- and many-body physics that is signified by single- and multi-frequency oscillatory dynamics corresponding to the formation of many-body bound states. Finally, we discuss concrete experimental implementations in ultracold atoms.

Quantum entanglement: facts and fiction - how wrong was Einstein after all?

PubMed

Nordén, Bengt

2016-01-01

Einstein was wrong with his 1927 Solvay Conference claim that quantum mechanics is incomplete and incapable of describing diffraction of single particles. However, the Einstein-Podolsky-Rosen paradox of entangled pairs of particles remains lurking with its 'spooky action at a distance'. In molecules quantum entanglement can be viewed as basis of both chemical bonding and excitonic states. The latter are important in many biophysical contexts and involve coupling between subsystems in which virtual excitations lead to eigenstates of the total Hamiltonian, but not for the separate subsystems. The author questions whether atomic or photonic systems may be probed to prove that particles or photons may stay entangled over large distances and display the immediate communication with each other that so concerned Einstein. A dissociating hydrogen molecule is taken as a model of a zero-spin entangled system whose angular momenta are in principle possible to probe for this purpose. In practice, however, spins randomize as a result of interactions with surrounding fields and matter. Similarly, no experiment seems yet to provide unambiguous evidence of remaining entanglement between single photons at large separations in absence of mutual interaction, or about immediate (superluminal) communication. This forces us to reflect again on what Einstein really had in mind with the paradox, viz. a probabilistic interpretation of a wave function for an ensemble of identically prepared states, rather than as a statement about single particles. Such a prepared state of many particles would lack properties of quantum entanglement that make it so special, including the uncertainty upon which safe quantum communication is assumed to rest. An example is Zewail's experiment showing visible resonance in the dissociation of a coherently vibrating ensemble of NaI molecules apparently violating the uncertainty principle. Einstein was wrong about diffracting single photons where space-like anti-bunching observations have proven recently their non-local character and how observation in one point can remotely affect the outcome in other points. By contrast, long range photon entanglement with immediate, superluminal response is still an elusive, possibly partly misunderstood issue. The author proposes that photons may entangle over large distances only if some interaction exists via fields that cannot propagate faster than the speed of light. An experiment to settle this 'interaction hypothesis' is suggested.

Satisfying the Einstein-Podolsky-Rosen criterion with massive particles.

PubMed

Peise, J; Kruse, I; Lange, K; Lücke, B; Pezzè, L; Arlt, J; Ertmer, W; Hammerer, K; Santos, L; Smerzi, A; Klempt, C

2015-11-27

In 1935, Einstein, Podolsky and Rosen (EPR) questioned the completeness of quantum mechanics by devising a quantum state of two massive particles with maximally correlated space and momentum coordinates. The EPR criterion qualifies such continuous-variable entangled states, where a measurement of one subsystem seemingly allows for a prediction of the second subsystem beyond the Heisenberg uncertainty relation. Up to now, continuous-variable EPR correlations have only been created with photons, while the demonstration of such strongly correlated states with massive particles is still outstanding. Here we report on the creation of an EPR-correlated two-mode squeezed state in an ultracold atomic ensemble. The state shows an EPR entanglement parameter of 0.18(3), which is 2.4 s.d. below the threshold 1/4 of the EPR criterion. We also present a full tomographic reconstruction of the underlying many-particle quantum state. The state presents a resource for tests of quantum nonlocality and a wide variety of applications in the field of continuous-variable quantum information and metrology.

Satisfying the Einstein-Podolsky-Rosen criterion with massive particles

NASA Astrophysics Data System (ADS)

Peise, J.; Kruse, I.; Lange, K.; Lücke, B.; Pezzè, L.; Arlt, J.; Ertmer, W.; Hammerer, K.; Santos, L.; Smerzi, A.; Klempt, C.

2015-11-01

In 1935, Einstein, Podolsky and Rosen (EPR) questioned the completeness of quantum mechanics by devising a quantum state of two massive particles with maximally correlated space and momentum coordinates. The EPR criterion qualifies such continuous-variable entangled states, where a measurement of one subsystem seemingly allows for a prediction of the second subsystem beyond the Heisenberg uncertainty relation. Up to now, continuous-variable EPR correlations have only been created with photons, while the demonstration of such strongly correlated states with massive particles is still outstanding. Here we report on the creation of an EPR-correlated two-mode squeezed state in an ultracold atomic ensemble. The state shows an EPR entanglement parameter of 0.18(3), which is 2.4 s.d. below the threshold 1/4 of the EPR criterion. We also present a full tomographic reconstruction of the underlying many-particle quantum state. The state presents a resource for tests of quantum nonlocality and a wide variety of applications in the field of continuous-variable quantum information and metrology.

Physical process first law and increase of horizon entropy for black holes in Einstein-Gauss-Bonnet gravity.

PubMed

Chatterjee, Ayan; Sarkar, Sudipta

2012-03-02

We establish the physical process version of the first law by studying small perturbations of a stationary black hole with a regular bifurcation surface in Einstein-Gauss-Bonnet gravity. Our result shows that when the stationary black hole is perturbed by a matter stress energy tensor and finally settles down to a new stationary state, the Wald entropy increases as long as the matter satisfies the null energy condition.

Nonlinear Schrödinger equations for Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Galati, Luigi; Zheng, Shijun

2013-10-01

The Gross-Pitaevskii equation, or more generally the nonlinear Schrödinger equation, models the Bose-Einstein condensates in a macroscopic gaseous superfluid wave-matter state in ultra-cold temperature. We provide analytical study of the NLS with L2 initial data in order to understand propagation of the defocusing and focusing waves for the BEC mechanism in the presence of electromagnetic fields. Numerical simulations are performed for the two-dimensional GPE with anisotropic quadratic potentials.

Comparison of rotational temperature derived from ground-based OH airglow observations with TIMED/SABER to evaluate the Einstein Coefficients

NASA Astrophysics Data System (ADS)

Liu, W.; Xu, J.; Smith, A. K.; Yuan, W.

2017-12-01

Ground-based observations of the OH(9-4, 8-3, 6-2, 5-1, 3-0) band airglows over Xinglong, China (40°24'N, 117°35'E) from December 2011 to 2014 are used to calculate rotational temperatures. The temperatures are calculated using five commonly used Einstein coefficient datasets. The kinetic temperature from TIMED/SABER is completely independent of the OH rotational temperature. SABER temperatures are weighted vertically by weighting functions calculated for each emitting vibrational state from two SABER OH volume emission rate profiles. By comparing the ground-based OH rotational temperature with SABER's, five Einstein coefficient datasets are evaluated. The results show that temporal variations of the rotational temperatures are well correlated with SABER's; the linear correlation coefficients are higher than 0.72, but the slopes of the fit between the SABER and rotational temperatures are not equal to 1. The rotational temperatures calculated using each set of Einstein coefficients produce a different bias with respect to SABER; these are evaluated over each of vibrational levels to assess the best match. It is concluded that rotational temperatures determined using any of the available Einstein coefficient datasets have systematic errors. However, of the five sets of coefficients, the rotational temperature derived with the Langhoff et al.'s (1986) set is most consistent with SABER. In order to get a set of optimal Einstein coefficients for rotational temperature derivation, we derive the relative values from ground-based OH spectra and SABER temperatures statistically using three year data. The use of a standard set of Einstein coefficients will be beneficial for comparing rotational temperatures observed at different sites.

A P2-Type Layered Superionic Conductor Ga-Doped Na2 Zn2 TeO6 for All-Solid-State Sodium-Ion Batteries.

PubMed

Li, Yuyu; Deng, Zhi; Peng, Jian; Chen, Enyi; Yu, Yao; Li, Xiang; Luo, Jiahuan; Huang, Yangyang; Zhu, Jinlong; Fang, Chun; Li, Qing; Han, Jiantao; Huang, Yunhui

2018-01-24

Here, a P2-type layered Na 2 Zn 2 TeO 6 (NZTO) is reported with a high Na + ion conductivity ≈0.6×10 -3  S cm -1 at room temperature (RT), which is comparable to the currently best Na 1+n Zr 2 Si n P 3-n O 12 NASICON structure. As small amounts of Ga 3+ substitutes for Zn 2+ , more Na + vacancies are introduced in the interlayer gaps, which greatly reduces strong Na + -Na + coulomb interactions. Ga-substituted NZTO exhibits a superionic conductivity of ≈1.1×10 -3  S cm -1 at RT, and excellent phase and electrochemical stability. All solid-state batteries have been successfully assembled with a capacity of ≈70 mAh g -1 over 10 cycles with a rate of 0.2 C at 80 °C. 23 Na nuclear magnetic resonance (NMR) studies on powder samples show intra-grain (bulk) diffusion coefficients D NMR on the order of 12.35×10 -12  m 2  s -1 at 65 °C that corresponds to a conductivity σ NMR of 8.16×10 -3  S cm -1 , assuming the Nernst-Einstein equation, which thus suggests a new perspective of fast Na + ion conductor for advanced sodium ion batteries. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

New Information about Albert Einstein's Brain.

PubMed

Falk, Dean

2009-01-01

In order to glean information about hominin (or other) brains that no longer exist, details of external neuroanatomy that are reproduced on endocranial casts (endocasts) from fossilized braincases may be described and interpreted. Despite being, of necessity, speculative, such studies can be very informative when conducted in light of the literature on comparative neuroanatomy, paleontology, and functional imaging studies. Albert Einstein's brain no longer exists in an intact state, but there are photographs of it in various views. Applying techniques developed from paleoanthropology, previously unrecognized details of external neuroanatomy are identified on these photographs. This information should be of interest to paleoneurologists, comparative neuroanatomists, historians of science, and cognitive neuroscientists. The new identifications of cortical features should also be archived for future scholars who will have access to additional information from improved functional imaging technology. Meanwhile, to the extent possible, Einstein's cerebral cortex is investigated in light of available data about variation in human sulcal patterns. Although much of his cortical surface was unremarkable, regions in and near Einstein's primary somatosensory and motor cortices were unusual. It is possible that these atypical aspects of Einstein's cerebral cortex were related to the difficulty with which he acquired language, his preference for thinking in sensory impressions including visual images rather than words, and his early training on the violin.

Domain wall suppression in trapped mixtures of Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Pepe, Francesco V.; Facchi, Paolo; Florio, Giuseppe; Pascazio, Saverio

2012-08-01

The ground-state energy of a binary mixture of Bose-Einstein condensates can be estimated for large atomic samples by making use of suitably regularized Thomas-Fermi density profiles. By exploiting a variational method on the trial densities the energy can be computed by explicitly taking into account the normalization condition. This yields analytical results and provides the basis for further improvement of the approximation. As a case study, we consider a binary mixture of 87Rb atoms in two different hyperfine states in a double-well potential and discuss the energy crossing between density profiles with different numbers of domain walls, as the number of particles and the interspecies interaction vary.

Bose-Einstein condensate of rigid rotor molecules

NASA Astrophysics Data System (ADS)

Jones, Evan; Smith, Joseph; Rittenhouse, Seth; Peden, Brandon; Wilson, Ryan

2017-04-01

We study the ground state phases of a quasi-two-dimensional Bose-Einstein condensate (BEC) of dipolar rigid rotor molecules subject to a DC electric field. In the high-field limit, this system acquires the properties of the fully polarized dipolar BEC, which exhibits a roton-maxon excitation spectrum, and has been thoroughly studied in the theoretical literature. In the weak-field limit, however, qualitatively new physics emerges due to the competition between the (weak) applied field and internal electric fields, which are produced by the molecules themselves. We characterize the ground states of this system, and study its unique dielectric properties. We gratefully acknowledge support from the National Science Foundation under Grant No. PHYS-1516421.

Demonstration of Einstein-Podolsky-Rosen steering with enhanced subchannel discrimination

NASA Astrophysics Data System (ADS)

Sun, Kai; Ye, Xiang-Jun; Xiao, Ya; Xu, Xiao-Ye; Wu, Yu-Chun; Xu, Jin-Shi; Chen, Jing-Ling; Li, Chuan-Feng; Guo, Guang-Can

2018-03-01

Einstein-Podolsky-Rosen (EPR) steering describes a quantum nonlocal phenomenon in which one party can nonlocally affect the other's state through local measurements. It reveals an additional concept of quantum non-locality, which stands between quantum entanglement and Bell nonlocality. Recently, a quantum information task named as subchannel discrimination (SD) provides a necessary and sufficient characterization of EPR steering. The success probability of SD using steerable states is higher than using any unsteerable states, even when they are entangled. However, the detailed construction of such subchannels and the experimental realization of the corresponding task are still technologically challenging. In this work, we designed a feasible collection of subchannels for a quantum channel and experimentally demonstrated the corresponding SD task where the probabilities of correct discrimination are clearly enhanced by exploiting steerable states. Our results provide a concrete example to operationally demonstrate EPR steering and shine a new light on the potential application of EPR steering.

Sign of coupling in barrier-separated Bose-Einstein condensates and stability of double-ring systems

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

Brand, J.; Haigh, T. J.; Zuelicke, U.

We revisit recent claims about the instability of nonrotating tunnel coupled annular Bose-Einstein condensates leading to the emergence of angular momentum Josephson oscillation [Phys. Rev. Lett. 98, 050401 (2007)]. It was predicted that all stationary states with uniform density become unstable in certain parameter regimes. By careful analysis, we arrive at a different conclusion. We show that there is a stable nonrotating and uniform ground state for any value of the tunnel coupling and repulsive interactions. The instability of an excited state with {pi} phase difference between the condensates can be interpreted in terms of the familiar snake instability. Wemore » further discuss the sign of the tunnel coupling through a separating barrier, which carries significance for the nature of the stationary states. It is found to always be negative for physical reasons.« less

Demonstration of Monogamy Relations for Einstein-Podolsky-Rosen Steering in Gaussian Cluster States.

PubMed

Deng, Xiaowei; Xiang, Yu; Tian, Caixing; Adesso, Gerardo; He, Qiongyi; Gong, Qihuang; Su, Xiaolong; Xie, Changde; Peng, Kunchi

2017-06-09

Understanding how quantum resources can be quantified and distributed over many parties has profound applications in quantum communication. As one of the most intriguing features of quantum mechanics, Einstein-Podolsky-Rosen (EPR) steering is a useful resource for secure quantum networks. By reconstructing the covariance matrix of a continuous variable four-mode square Gaussian cluster state subject to asymmetric loss, we quantify the amount of bipartite steering with a variable number of modes per party, and verify recently introduced monogamy relations for Gaussian steerability, which establish quantitative constraints on the security of information shared among different parties. We observe a very rich structure for the steering distribution, and demonstrate one-way EPR steering of the cluster state under Gaussian measurements, as well as one-to-multimode steering. Our experiment paves the way for exploiting EPR steering in Gaussian cluster states as a valuable resource for multiparty quantum information tasks.

Demonstration of Monogamy Relations for Einstein-Podolsky-Rosen Steering in Gaussian Cluster States

NASA Astrophysics Data System (ADS)

Deng, Xiaowei; Xiang, Yu; Tian, Caixing; Adesso, Gerardo; He, Qiongyi; Gong, Qihuang; Su, Xiaolong; Xie, Changde; Peng, Kunchi

2017-06-01

Understanding how quantum resources can be quantified and distributed over many parties has profound applications in quantum communication. As one of the most intriguing features of quantum mechanics, Einstein-Podolsky-Rosen (EPR) steering is a useful resource for secure quantum networks. By reconstructing the covariance matrix of a continuous variable four-mode square Gaussian cluster state subject to asymmetric loss, we quantify the amount of bipartite steering with a variable number of modes per party, and verify recently introduced monogamy relations for Gaussian steerability, which establish quantitative constraints on the security of information shared among different parties. We observe a very rich structure for the steering distribution, and demonstrate one-way EPR steering of the cluster state under Gaussian measurements, as well as one-to-multimode steering. Our experiment paves the way for exploiting EPR steering in Gaussian cluster states as a valuable resource for multiparty quantum information tasks.

Can the Stark-Einstein law resolve the measurement problem from an animate perspective?

PubMed

Thaheld, Fred H

2015-09-01

Analysis of the Stark-Einstein law as it applies to the retinal molecule, which is part of the rhodopsin molecule within the rod cells of the retina, reveals that it may provide the solution to the measurement problem from an animate perspective. That it represents a natural boundary where the Schrödinger equation or wave function automatically goes from linear to nonlinear while remaining in a deterministic state. It will be possible in the near future to subject this theory to empirical tests as has been previously proposed. This analysis provides a contrast to the many decades well studied and debated inanimate measurement problem and would represent an addition to the Stark-Einstein law involving information carried by the photon. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Einstein's osmotic equilibrium of colloidal suspensions in conservative force fields

NASA Astrophysics Data System (ADS)

Fu, Jinxin; Ou-Yang, H. Daniel

2014-09-01

Predicted by Einstein in his 1905 paper on Brownian motion, colloidal particles in suspension reach osmotic equilibrium under gravity. The idea was demonstrated by J.B. Perrin to win Nobel Prize in Physics in 1926. We show Einstein's equation for osmotic equilibrium can be applied to colloids in a conservative force field generated by optical gradient forces. We measure the osmotic equation of state of 100nm Polystyrene latex particles in the presence of KCl salt and PEG polymer. We also obtain the osmotic compressibility, which is important for determining colloidal stability and the internal chemical potential, which is useful for predicting the phase transition of colloidal systems. This generalization allows for the use of any conservative force fields for systems ranging from colloidal systems to macromolecular solutions.

Cosmological Constant: A Lesson from Bose-Einstein Condensates

NASA Astrophysics Data System (ADS)

Finazzi, Stefano; Liberati, Stefano; Sindoni, Lorenzo

2012-02-01

The cosmological constant is one of the most pressing problems in modern physics. We address this issue from an emergent gravity standpoint, by using an analogue gravity model. Indeed, the dynamics of the emergent metric in a Bose-Einstein condensate can be described by a Poisson-like equation with a vacuum source term reminiscent of a cosmological constant. The direct computation of this term shows that in emergent gravity scenarios this constant may be naturally much smaller than the naive ground-state energy of the emergent effective field theory. This suggests that a proper computation of the cosmological constant would require a detailed understanding about how Einstein equations emerge from the full microscopic quantum theory. In this light, the cosmological constant appears as a decisive test bench for any quantum or emergent gravity scenario.

Cosmological constant: a lesson from Bose-Einstein condensates.

PubMed

Finazzi, Stefano; Liberati, Stefano; Sindoni, Lorenzo

2012-02-17

The cosmological constant is one of the most pressing problems in modern physics. We address this issue from an emergent gravity standpoint, by using an analogue gravity model. Indeed, the dynamics of the emergent metric in a Bose-Einstein condensate can be described by a Poisson-like equation with a vacuum source term reminiscent of a cosmological constant. The direct computation of this term shows that in emergent gravity scenarios this constant may be naturally much smaller than the naive ground-state energy of the emergent effective field theory. This suggests that a proper computation of the cosmological constant would require a detailed understanding about how Einstein equations emerge from the full microscopic quantum theory. In this light, the cosmological constant appears as a decisive test bench for any quantum or emergent gravity scenario.

Compact setup for the production of {sup 87}Rb |F = 2, m{sub F} = + 2〉 Bose-Einstein condensates in a hybrid trap

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

Nolli, Raffaele; Venturelli, Michela; Marmugi, Luca, E-mail: l.marmugi@ucl.ac.uk

We present a compact experimental apparatus for Bose-Einstein condensation of {sup 87}Rb in the |F  =  2, m{sub F} = + 2〉 state. A pre-cooled atomic beam of {sup 87}Rb is obtained by using an unbalanced magneto-optical trap, allowing controlled transfer of trapped atoms from the first vacuum chamber to the science chamber. Here, atoms are transferred to a hybrid trap, as produced by overlapping a magnetic quadrupole trap with a far-detuned optical trap with crossed beam configuration, where forced radiofrequency evaporation is realized. The final evaporation leading to Bose-Einstein condensation is then performed by exponentially lowering the optical trapmore » depth. Control and stabilization systems of the optical trap beams are discussed in detail. The setup reliably produces a pure condensate in the |F = 2, m{sub F} = + 2〉 state in 50 s, which includes 33 s loading of the science magneto-optical trap and 17 s forced evaporation.« less

Deriving Einstein-Podolsky-Rosen steering inequalities from the few-body Abner Shimony inequalities

NASA Astrophysics Data System (ADS)

Zhou, Jie; Meng, Hui-Xian; Jiang, Shu-Han; Xu, Zhen-Peng; Ren, Changliang; Su, Hong-Yi; Chen, Jing-Ling

2018-04-01

For the Abner Shimony (AS) inequalities, the simplest unified forms of directions attaining the maximum quantum violation are investigated. Based on these directions, a family of Einstein-Podolsky-Rosen (EPR) steering inequalities is derived from the AS inequalities in a systematic manner. For these inequalities, the local hidden state (LHS) bounds are strictly less than the local hidden variable (LHV) bounds. This means that the EPR steering is a form of quantum nonlocality strictly weaker than Bell nonlocality.

Gauge-gravity duality and the black hole interior.

PubMed

Marolf, Donald; Polchinski, Joseph

2013-10-25

We present a further argument that typical black holes with field theory duals have firewalls at the horizon. This argument makes no reference to entanglement between the black hole and any distant system, and so is not evaded by identifying degrees of freedom inside the black hole with those outside. We also address the Einstein-Rosen=Einstein-Podolsky-Rosen conjecture of Maldacena and Susskind, arguing that the correlations in generic highly entangled states cannot be geometrized as a smooth wormhole.

Detection scheme for acoustic quantum radiation in Bose-Einstein condensates.

PubMed

Schützhold, Ralf

2006-11-10

Based on doubly detuned Raman transitions between (meta)stable atomic or molecular states and recently developed atom counting techniques, a detection scheme for sound waves in dilute Bose-Einstein condensates is proposed whose accuracy might reach down to the level of a few or even single phonons. This scheme could open up a new range of applications including the experimental observation of quantum radiation phenomena such as the Hawking effect in sonic black-hole analogues or the acoustic analogue of cosmological particle creation.

Einstein unmasked

NASA Astrophysics Data System (ADS)

Foster, Brian

2008-09-01

This is a remarkable and, at times, bewilderingly diverse volume. Consisting of 20 essays that represent the proceedings of a conference held in 2005 in Berlin, Germany, during the International Year of Physics, it offers insights into Einstein's influence on a swathe of human activity. In the introduction the distinguished editors make some remarkable claims for the book, calling it "an unique attempt" and saying that "there is no better introduction to...string theory", while the first essay states "Not since Newton's Principia..." Clearly this is a volume that aspires to high standards.

Bose-Einstein condensation of dark matter axions.

PubMed

Sikivie, P; Yang, Q

2009-09-11

We show that cold dark matter axions thermalize and form a Bose-Einstein condensate (BEC). We obtain the axion state in a homogeneous and isotropic universe, and derive the equations governing small axion perturbations. Because they form a BEC, axions differ from ordinary cold dark matter in the nonlinear regime of structure formation and upon entering the horizon. Axion BEC provides a mechanism for the production of net overall rotation in dark matter halos, and for the alignment of cosmic microwave anisotropy multipoles.

Entropy density of an adiabatic relativistic Bose-Einstein condensate star

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

Khaidir, Ahmad Firdaus; Kassim, Hasan Abu; Yusof, Norhasliza

Inspired by recent works, we investigate how the thermodynamics parameters (entropy, temperature, number density, energy density, etc) of Bose-Einstein Condensate star scale with the structure of the star. Below the critical temperature in which the condensation starts to occur, we study how the entropy behaves with varying temperature till it reaches its own stability against gravitational collapse and singularity. Compared to photon gases (pressure is described by radiation) where the chemical potential, μ is zero, entropy of photon gases obeys the Stefan-Boltzmann Law for a small values of T while forming a spiral structure for a large values of Tmore » due to general relativity. The entropy density of Bose-Einstein Condensate is obtained following the similar sequence but limited under critical temperature condition. We adopt the scalar field equation of state in Thomas-Fermi limit to study the characteristics of relativistic Bose-Einstein condensate under varying temperature and entropy. Finally, we obtain the entropy density proportional to (σT{sup 3}-3T) which obeys the Stefan-Boltzmann Law in ultra-relativistic condition.« less

Robust vortex lines, vortex rings, and hopfions in three-dimensional Bose-Einstein condensates

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

Bisset, R. N.; Wang, Wenlong; Ticknor, Christopher

Performing a systematic Bogoliubov–de Gennes spectral analysis, we illustrate that stationary vortex lines, vortex rings, and more exotic states, such as hopfions, are robust in three-dimensional atomic Bose-Einstein condensates, for large parameter intervals. Importantly, we find that the hopfion can be stabilized in a simple parabolic trap, without the need for trap rotation or inhomogeneous interactions. We supplement our spectral analysis by studying the dynamics of such stationary states; we find them to be robust against significant perturbations of the initial state. In the unstable regimes, we not only identify the unstable mode, such as a quadrupolar or hexapolar mode,more » but we also observe the corresponding instability dynamics. Moreover, deep in the Thomas-Fermi regime, we investigate the particlelike behavior of vortex rings and hopfions.« less

Robust vortex lines, vortex rings, and hopfions in three-dimensional Bose-Einstein condensates

DOE PAGES

Bisset, R. N.; Wang, Wenlong; Ticknor, Christopher; ...

2015-12-07

Performing a systematic Bogoliubov–de Gennes spectral analysis, we illustrate that stationary vortex lines, vortex rings, and more exotic states, such as hopfions, are robust in three-dimensional atomic Bose-Einstein condensates, for large parameter intervals. Importantly, we find that the hopfion can be stabilized in a simple parabolic trap, without the need for trap rotation or inhomogeneous interactions. We supplement our spectral analysis by studying the dynamics of such stationary states; we find them to be robust against significant perturbations of the initial state. In the unstable regimes, we not only identify the unstable mode, such as a quadrupolar or hexapolar mode,more » but we also observe the corresponding instability dynamics. Moreover, deep in the Thomas-Fermi regime, we investigate the particlelike behavior of vortex rings and hopfions.« less

Pseudo-steady-state non-Gaussian Einstein-Podolsky-Rosen steering of massive particles in pumped and damped Bose-Hubbard dimers

NASA Astrophysics Data System (ADS)

Olsen, M. K.

2017-02-01

We propose and analyze a pumped and damped Bose-Hubbard dimer as a source of continuous-variable Einstein-Podolsky-Rosen (EPR) steering with non-Gaussian statistics. We use and compare the results of the approximate truncated Wigner and the exact positive-P representation to calculate and compare the predictions for intensities, second-order quantum correlations, and third- and fourth-order cumulants. We find agreement for intensities and the products of inferred quadrature variances, which indicate that states demonstrating the EPR paradox are present. We find clear signals of non-Gaussianity in the quantum states of the modes from both the approximate and exact techniques, with quantitative differences in their predictions. Our proposed experimental configuration is extrapolated from current experimental techniques and adds another apparatus to the current toolbox of quantum atom optics.

Entanglement and nonlocality in multi-particle systems

NASA Astrophysics Data System (ADS)

Reid, Margaret D.; He, Qiong-Yi; Drummond, Peter D.

2012-02-01

Entanglement, the Einstein-Podolsky-Rosen (EPR) paradox and Bell's failure of local-hiddenvariable (LHV) theories are three historically famous forms of "quantum nonlocality". We give experimental criteria for these three forms of nonlocality in multi-particle systems, with the aim of better understanding the transition from microscopic to macroscopic nonlocality. We examine the nonlocality of N separated spin J systems. First, we obtain multipartite Bell inequalities that address the correlation between spin values measured at each site, and then we review spin squeezing inequalities that address the degree of reduction in the variance of collective spins. The latter have been particularly useful as a tool for investigating entanglement in Bose-Einstein condensates (BEC). We present solutions for two topical quantum states: multi-qubit Greenberger-Horne-Zeilinger (GHZ) states, and the ground state of a two-well BEC.

Nonlocality of the original Einstein-Podolsky-Rosen state

NASA Astrophysics Data System (ADS)

Cohen, O.

1997-11-01

We examine the properties and behavior of the original Einstein-Podolsky-Rosen (EPR) wave function [Phys. Rev. 47, 777 (1935)] and related Gaussian-correlated wave functions. We assess the degree of entanglement of these wave functions and consider an argument of Bell [Ann. (N.Y.) Acad. Sci. 480, 263 (1986)] based on the Wigner phase-space distribution [Phys. Rev. 40, 749 (1932)], which implies that the original EPR correlations can accommodate a local hidden-variable description. We extend Bell's analysis to the related Gaussian wave functions. We then show that it is possible to identify definite nonlocal aspects for the original EPR state and related states. We describe possible experiments that would demonstrate these nonlocal features through violations of Bell inequalities. The implications of our results, and in particular their relevance for the causal interpretation of quantum mechanics, are considered.

Low-energy excitations of a Bose-Einstein condensate of rigid rotor molecules

NASA Astrophysics Data System (ADS)

Smith, Joseph; Jones, Evan; Rittenhouse, Seth; Wilson, Ryan; Peden, Brandon

2017-04-01

We investigate the properties of the ground state and low-lying excitations of an oblate Bose-Einstein condensate composed of rigid rotor molecules in the presence of an external polarizing electric field. We build in a quantum model of molecular polarizability by including the full manifold of rotational states. The interplay between spatial and microscopic degrees of freedom via feedback between the molecular polarizability and inter-molecular dipole-dipole interactions leads to a rich quasi-particle spectrum. Under large applied fields, we reproduce the well-understood density-wave rotonization that appears in a fully polarized dipolar BEC, but under smaller applied fields, we predict the emergence of a spin wave instability and possible new stable ground state phases. We gratefully acknowledge support from the National Science Foundation under Grant No. PHYS-1516421.

Interferometry with non-classical motional states of a Bose-Einstein condensate.

PubMed

van Frank, S; Negretti, A; Berrada, T; Bücker, R; Montangero, S; Schaff, J-F; Schumm, T; Calarco, T; Schmiedmayer, J

2014-05-30

The Ramsey interferometer is a prime example of precise control at the quantum level. It is usually implemented using internal states of atoms, molecules or ions, for which powerful manipulation procedures are now available. Whether it is possible to control external degrees of freedom of more complex, interacting many-body systems at this level remained an open question. Here we demonstrate a two-pulse Ramsey-type interferometer for non-classical motional states of a Bose-Einstein condensate in an anharmonic trap. The control sequences used to manipulate the condensate wavefunction are obtained from optimal control theory and are directly optimized to maximize the interferometric contrast. They permit a fast manipulation of the atomic ensemble compared to the intrinsic decay processes and many-body dephasing effects. This allows us to reach an interferometric contrast of 92% in the experimental implementation.

Non-ideal teleportation of tripartite entanglement: Einstein-Podolsky-Rosen versus Greenberger-Horne-Zeilinger schemes

NASA Astrophysics Data System (ADS)

Cunha, Márcio M.; Fonseca, E. A.; Moreno, M. G. M.; Parisio, Fernando

2017-10-01

Channels composed by Einstein-Podolsky-Rosen (EPR) pairs are capable of teleporting arbitrary multipartite states. The question arises whether EPR channels are also optimal against imperfections. In particular, the teleportation of Greenberger-Horne-Zeilinger states (GHZ) requires three EPR states as the channel and full measurements in the Bell basis. We show that, by using two GHZ states as the channel, it is possible to transport any unknown three-qubit state of the form c_0|000\\rangle +c_1|111\\rangle . The teleportation is made through measurements in the GHZ basis, and, to obtain deterministic results, in most of the investigated scenarios, four out of the eight elements of the basis need to be unambiguously distinguished. Most importantly, we show that when both systematic errors and noise are considered, the fidelity of the teleportation protocol is higher when a GHZ channel is used in comparison with that of a channel composed by EPR pairs.

Beyond Gisin’s Theorem and its Applications: Violation of Local Realism by Two-Party Einstein-Podolsky-Rosen Steering

PubMed Central

Chen, Jing-Ling; Su, Hong-Yi; Xu, Zhen-Peng; Wu, Yu-Chun; Wu, Chunfeng; Ye, Xiang-Jun; Żukowski, Marek; Kwek, L. C.

2015-01-01

We demonstrate here that for a given mixed multi-qubit state if there are at least two observers for whom mutual Einstein-Podolsky-Rosen steering is possible, i.e. each observer is able to steer the other qubits into two different pure states by spontaneous collapses due to von Neumann type measurements on his/her qubit, then nonexistence of local realistic models is fully equivalent to quantum entanglement (this is not so without this condition). This result leads to an enhanced version of Gisin’s theorem (originally: all pure entangled states violate local realism). Local realism is violated by all mixed states with the above steering property. The new class of states allows one e.g. to perform three party secret sharing with just pairs of entangled qubits, instead of three qubit entanglements (which are currently available with low fidelity). This significantly increases the feasibility of having high performance versions of such protocols. Finally, we discuss some possible applications. PMID:26108704

Shortcut loading a Bose–Einstein condensate into an optical lattice

NASA Astrophysics Data System (ADS)

Zhou, Xiaoji; Jin, Shengjie; Schmiedmayer, Jörg

2018-05-01

We present an effective and fast (few microseconds) procedure for transferring a Bose–Einstein condensate from the ground state in a harmonic trap into the desired bands of an optical lattice. Our shortcut method is a designed pulse sequence where the time duration and the interval in each step are fully optimized in order to maximize robustness and fidelity of the final state with respect to the target state. The atoms can be prepared in a single band with even or odd parity, and superposition states of different bands can be prepared and manipulated. Furthermore, we extend this idea to the case of two-dimensional or three-dimensional optical lattices where the energies of excited states are degenerate. We experimentally demonstrate various examples and show very good agreement with the theoretical model. Efficient shortcut methods will find applications in the preparation of quantum systems, in quantum information processing, in precise measurement and as a starting point to investigate dynamics in excited bands.

Bose-Einstein condensates in charged black-hole spacetimes

NASA Astrophysics Data System (ADS)

Castellanos, Elías; Degollado, Juan Carlos; Lämmerzahl, Claus; Macías, Alfredo; Perlick, Volker

2018-01-01

We analyze Bose-Einstein condensates on three types of spherically symmetric and static charged black-hole spacetimes: the Reissner-Nordström spacetime, Hoffmann's Born-Infeld black-hole spacetime, and the regular Ayón-Beato-García spacetime. The Bose-Einstein condensate is modeled in terms of a massive scalar field that satisfies a Klein-Gordon equation with a self-interaction term. The scalar field is assumed to be uncharged and not self-gravitating. If the mass parameter of the scalar field is chosen sufficiently small, there are quasi-bound states of the scalar field that may be interpreted as dark matter clouds. We estimate the size and the total energy of such clouds around charged supermassive black holes and we investigate if their observable features can be used for discriminating between the different types of charged black holes.

Einstein-Podolsky-Rosen-steering swapping between two Gaussian multipartite entangled states

NASA Astrophysics Data System (ADS)

Wang, Meihong; Qin, Zhongzhong; Wang, Yu; Su, Xiaolong

2017-08-01

Multipartite Einstein-Podolsky-Rosen (EPR) steering is a useful quantum resource for quantum communication in quantum networks. It has potential applications in secure quantum communication, such as one-sided device-independent quantum key distribution and quantum secret sharing. By distributing optical modes of a multipartite entangled state to space-separated quantum nodes, a local quantum network can be established. Based on the existing multipartite EPR steering in a local quantum network, secure quantum communication protocol can be accomplished. In this manuscript, we present swapping schemes for EPR steering between two space-separated Gaussian multipartite entangled states, which can be used to connect two space-separated quantum networks. Two swapping schemes, including the swapping between a tripartite Greenberger-Horne-Zeilinger (GHZ) entangled state and an EPR entangled state and that between two tripartite GHZ entangled states, are analyzed. Various types of EPR steering are presented after the swapping of two space-separated independent multipartite entanglement states without direct interaction, which can be used to implement quantum communication between two quantum networks. The presented schemes provide technical reference for more complicated quantum networks with EPR steering.

How device-independent approaches change the meaning of physical theory

NASA Astrophysics Data System (ADS)

Grinbaum, Alexei

2017-05-01

Dirac sought an interpretation of mathematical formalism in terms of physical entities and Einstein insisted that physics should describe ;the real states of the real systems;. While Bell inequalities put into question the reality of states, modern device-independent approaches do away with the idea of entities: physical theory may contain no physical systems. Focusing on the correlations between operationally defined inputs and outputs, device-independent methods promote a view more distant from the conventional one than Einstein's 'principle theories' were from 'constructive theories'. On the examples of indefinite causal orders and almost quantum correlations, we ask a puzzling question: if physical theory is not about systems, then what is it about? Device-independent models suggest that physical theory can be 'about' languages.

Concerning Dice and Divinity

NASA Astrophysics Data System (ADS)

Appleby, D. M.

2007-02-01

Einstein initially objected to the probabilistic aspect of quantum mechanics—the idea that God is playing at dice. Later he changed his ground, and focussed instead on the point that the Copenhagen Interpretation leads to what Einstein saw as the abandonment of physical realism. We argue here that Einstein's initial intuition was perfectly sound, and that it is precisely the fact that quantum mechanics is a fundamentally probabilistic theory which is at the root of all the controversies regarding its interpretation. Probability is an intrinsically logical concept. This means that the quantum state has an essentially logical significance. It is extremely difficult to reconcile that fact with Einstein's belief, that it is the task of physics to give us a vision of the world apprehended sub specie aeternitatis. Quantum mechanics thus presents us with a simple choice: either to follow Einstein in looking for a theory which is not probabilistic at the fundamental level, or else to accept that physics does not in fact put us in the position of God looking down on things from above. There is a widespread fear that the latter alternative must inevitably lead to a greatly impoverished, positivistic view of physical theory. It appears to us, however, that the truth is just the opposite. The Einsteinian vision is much less attractive than it seems at first sight. In particular, it is closely connected with philosophical reductionism.

Einstein A coefficients for rovibronic lines of the A2Π → X2Σ+ and B2Σ+ → X2Σ+ transitions of CaH and CaD

NASA Astrophysics Data System (ADS)

Alavi, S. Fatemeh; Shayesteh, Alireza

2018-02-01

Calcium monohydride is an important diatomic molecule appearing in the spectra of sunspots and M dwarfs. We report complete line lists with Einstein A coefficients for the A2Π-X2Σ+ and B2Σ+-X2Σ+ electronic transitions of CaH and CaD radicals. The most recent ab initio transition dipole moments and potential energy curves were used for the calculation of vibronic band intensities, taking the Herman-Wallis effect into account, and the rotational line strengths were calculated using the PGOPHER program of Western. For the A2Π and B2Σ+ excited states of CaH and CaD, new off-diagonal electronic matrix elements were included in the Hamiltonian matrix, and new sets of spectroscopic constants were determined in order to accurately reproduce the line positions and relative intensities of the observed branches in laboratory spectra. For both CaH and CaD isotopologues, Einstein A coefficients were calculated for all possible rovibronic transitions from the v΄ = 0-3 vibrational levels of the A2Π state and the v΄ = 0-2 vibrational levels of the B2Σ+ state to the v″ = 0-4 vibrational levels of the X2Σ+ ground state. The line lists and intensities reported here can be used to accurately determine the amounts of CaH and CaD in stellar environments.

Production of large Bose-Einstein condensates in a magnetic-shield-compatible hybrid trap

NASA Astrophysics Data System (ADS)

Colzi, Giacomo; Fava, Eleonora; Barbiero, Matteo; Mordini, Carmelo; Lamporesi, Giacomo; Ferrari, Gabriele

2018-05-01

We describe the production of large 23Na Bose-Einstein condensates in a hybrid trap characterized by a weak magnetic field quadrupole and a tightly focused infrared beam. The use of small magnetic field gradients makes the trap compatible with the state-of-the-art magnetic shields. By taking advantage of the deep cooling and high efficiency of gray molasses to improve the initial trap loading conditions, we produce condensates composed of as many as 7 million atoms in less than 30 s .

Optical orientation of the homogeneous nonequilibrium Bose-Einstein condensate of exciton polaritons

NASA Astrophysics Data System (ADS)

Korenev, V. L.

2012-07-01

A simple model, describing the steady state of the nonequilibrium polarization of a homogeneous Bose-Einstein condensate of exciton polaritons, is considered. It explains the suppression of spin splitting of a nonequilibrium polariton condensate in an external magnetic field, the linear polarization, the linear-to-circular polarization conversion, and the unexpected sign of the circular polarization of the condensate all on equal footing. It is shown that inverse effects are possible, to wit, spontaneous circular polarization and the enhancement of spin splitting of a nonequilibrium condensate of polaritons.

Gravity and the Spin-2 Planar Schrödinger Equation

NASA Astrophysics Data System (ADS)

Bergshoeff, Eric A.; Rosseel, Jan; Townsend, Paul K.

2018-04-01

A Schrödinger equation proposed for the Girvin-MacDonald-Platzman gapped spin-2 mode of fractional quantum Hall states is found from a novel nonrelativistic limit, applicable only in 2 +1 dimensions, of the massive spin-2 Fierz-Pauli field equations. It is also found from a novel null reduction of the linearized Einstein field equations in 3 +1 dimensions, and in this context a uniform distribution of spin-2 particles implies, via a Brinkmann-wave solution of the nonlinear Einstein equations, a confining harmonic oscillator potential for the individual particles.

Creation of long-term coherent optical memory via controlled nonlinear interactions in Bose-Einstein condensates.

PubMed

Zhang, Rui; Garner, Sean R; Hau, Lene Vestergaard

2009-12-04

A Bose-Einstein condensate confined in an optical dipole trap is used to generate long-term coherent memory for light, and storage times of more than 1 s are observed. Phase coherence of the condensate as well as controlled manipulations of elastic and inelastic atomic scattering processes are utilized to increase the storage fidelity by several orders of magnitude over previous schemes. The results have important applications for creation of long-distance quantum networks and for generation of entangled states of light and matter.

Nonthermal X-ray emission from winds of OB supergiants

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

Chen, W.; White, R.L.

1991-01-01

The mechanisms responsible for the hard X-ray emission of OB supergiants (OBSGs) are investigated theoretically, modifying the periodic-shock model of Lucy (1982). The physical processes discussed include (1) the particle acceleration (PA) mechanism and its effect on the structure of individual shocks, (2) the energy cutoff and spectral index of the relativistic electrons and ions, and (3) the efficiency of PA by shocks and its implications for the number densities of relativistic particles. The model is used to predict the spectrum and intensity of the dominant nonthermal X-ray emission source from OBSGs, and the results are shown to be inmore » good agreement with Einstein Observatory Solid-State Spectrometer observations of three OBSGs in Orion (Cassinelli and Swank, 1983). It is inferred that the surface magnetic fields of OBSGs are no greater than a few G, and that the PA rates are significantly lower than generally predicted for collisionless astrophysical shocks. 66 refs.« less

Bose-Einstein condensation and indirect excitons: a review.

PubMed

Combescot, Monique; Combescot, Roland; Dubin, François

2017-06-01

We review recent progress on Bose-Einstein condensation (BEC) of semiconductor excitons. The first part deals with theory, the second part with experiments. This Review is written at a time where the problem of exciton Bose-Einstein condensation has just been revived by the understanding that the exciton condensate must be dark because the exciton ground state is not coupled to light. Here, we theoretically discuss this missed understanding before providing its experimental support through experiments that scrutinize indirect excitons made of spatially separated electrons and holes. The theoretical part first discusses condensation of elementary bosons. In particular, the necessary inhibition of condensate fragmentation by exchange interaction is stressed, before extending the discussion to interacting bosons with spin degrees of freedom. The theoretical part then considers composite bosons made of two fermions like semiconductor excitons. The spin structure of the excitons is detailed, with emphasis on the crucial fact that ground-state excitons are dark: indeed, this imposes the exciton Bose-Einstein condensate to be not coupled to light in the dilute regime. Condensate fragmentations are then reconsidered. In particular, it is shown that while at low density, the exciton condensate is fully dark, it acquires a bright component, coherent with the dark one, beyond a density threshold: in this regime, the exciton condensate is 'gray'. The experimental part first discusses optical creation of indirect excitons in quantum wells, and the detection of their photoluminescence. Exciton thermalisation is also addressed, as well as available approaches to estimate the exciton density. We then switch to specific experiments where indirect excitons form a macroscopic fragmented ring. We show that such ring provides efficient electrostatic trapping in the region of the fragments where an essentially-dark exciton Bose-Einstein condensate is formed at sub-Kelvin bath temperatures. The macroscopic spatial coherence of the photoluminescence observed in this essentially dark region confirms this conclusion.

The A6Sigma+ - X6Sigma+ Transition of CrH, Einstein Coefficients and an Improved Description of the A State

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Ram, R. S.; Bernath, Peter F.; Parsons, C. G.; Galehouse, D.; Arnold, James O. (Technical Monitor)

2001-01-01

The spectrum of CrH has been reinvestigated in the 9000-15000/cm region using the Fourier transform spectrometer of the National Solar Observatory. The 1-0 and 1-1 bands of the A6Sigma+ - X6Sigma+ transition have been measured and improved spectroscopic constants have been determined. A value for the 2-0 band origin has been obtained from the band head using estimated spectroscopic constants. These data provide a set of much improved equilibrium vibrational and rotational constants for the A6Sigma+ state. An accurate description of the A-X transition has been obtained using a multi-reference configuration interaction approach. The inclusion of both scalar relativity and Cr 3s3p correlation are required to obtain a good description of both states. The ab initio computed Einstein coefficients and radiative lifetimes are reported.

Criteria for genuine N -partite continuous-variable entanglement and Einstein-Podolsky-Rosen steering

NASA Astrophysics Data System (ADS)

Teh, R. Y.; Reid, M. D.

2014-12-01

Following previous work, we distinguish between genuine N -partite entanglement and full N -partite inseparability. Accordingly, we derive criteria to detect genuine multipartite entanglement using continuous-variable (position and momentum) measurements. Our criteria are similar but different to those based on the van Loock-Furusawa inequalities, which detect full N -partite inseparability. We explain how the criteria can be used to detect the genuine N -partite entanglement of continuous variable states generated from squeezed and vacuum state inputs, including the continuous-variable Greenberger-Horne-Zeilinger state, with explicit predictions for up to N =9 . This makes our work accessible to experiment. For N =3 , we also present criteria for tripartite Einstein-Podolsky-Rosen (EPR) steering. These criteria provide a means to demonstrate a genuine three-party EPR paradox, in which any single party is steerable by the remaining two parties.

Cooling flexural modes of a mechanical oscillator by magnetically trapped Bose-Einstein-condensate atoms

NASA Astrophysics Data System (ADS)

Xu, Donghong; Xue, Fei

2017-12-01

We theoretically study cooling of flexural modes of a mechanical oscillator by Bose-Einstein-condensate (BEC) atoms (Rb87) trapped in a magnetic trap. The mechanical oscillator with a tiny magnet attached on one of its free ends produces an oscillating magnetic field. When its oscillating frequency matches certain hyperfine Zeeman energy of Rb87 atoms, the trapped BEC atoms are coupled out of the magnetic trap by the mechanical oscillator, flying away from the trap with stolen energy from the mechanical oscillator. Thus the mode temperature of the mechanical oscillator is reduced. The mode temperature of the steady state of mechanical oscillator, measured by the mean steady-state phonon number in the flexural mode of the mechanical oscillator, is analyzed. It is found that ground state (phonon number less than 1) may be accessible with optimal parameters of the hybrid system of mechanical oscillator and trapped BEC atoms.

Quantum-Fluctuation-Driven Crossover from a Dilute Bose-Einstein Condensate to a Macrodroplet in a Dipolar Quantum Fluid

NASA Astrophysics Data System (ADS)

Chomaz, L.; Baier, S.; Petter, D.; Mark, M. J.; Wächtler, F.; Santos, L.; Ferlaino, F.

2016-10-01

In a joint experimental and theoretical effort, we report on the formation of a macrodroplet state in an ultracold bosonic gas of erbium atoms with strong dipolar interactions. By precise tuning of the s -wave scattering length below the so-called dipolar length, we observe a smooth crossover of the ground state from a dilute Bose-Einstein condensate to a dense macrodroplet state of more than 2 ×104 atoms . Based on the study of collective excitations and loss features, we prove that quantum fluctuations stabilize the ultracold gas far beyond the instability threshold imposed by mean-field interactions. Finally, we perform expansion measurements, showing that although self-bound solutions are prevented by losses, the interplay between quantum stabilization and losses results in a minimal time-of-flight expansion velocity at a finite scattering length.

A projection gradient method for computing ground state of spin-2 Bose–Einstein condensates

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

Wang, Hanquan, E-mail: hanquan.wang@gmail.com; Yunnan Tongchang Scientific Computing and Data Mining Research Center, Kunming, Yunnan Province, 650221

In this paper, a projection gradient method is presented for computing ground state of spin-2 Bose–Einstein condensates (BEC). We first propose the general projection gradient method for solving energy functional minimization problem under multiple constraints, in which the energy functional takes real functions as independent variables. We next extend the method to solve a similar problem, where the energy functional now takes complex functions as independent variables. We finally employ the method into finding the ground state of spin-2 BEC. The key of our method is: by constructing continuous gradient flows (CGFs), the ground state of spin-2 BEC can bemore » computed as the steady state solution of such CGFs. We discretized the CGFs by a conservative finite difference method along with a proper way to deal with the nonlinear terms. We show that the numerical discretization is normalization and magnetization conservative and energy diminishing. Numerical results of the ground state and their energy of spin-2 BEC are reported to demonstrate the effectiveness of the numerical method.« less

Single and multiple vortex rings in three-dimensional Bose-Einstein condensates: Existence, stability, and dynamics

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

Wang, Wenlong; Bisset, R. N.; Ticknor, Christopher

In the present work, we explore the existence, stability, and dynamics of single- and multiple-vortex-ring states that can arise in Bose-Einstein condensates. Earlier works have illustrated the bifurcation of such states in the vicinity of the linear limit for isotropic or anisotropic three-dimensional harmonic traps. Here, we extend these states to the regime of large chemical potentials, the so-called Thomas-Fermi limit, and explore their properties such as equilibrium radii and inter-ring distance for multi-ring states, as well as their vibrational spectra and possible instabilities. In this limit, both the existence and stability characteristics can be partially traced to a particlemore » picture that considers the rings as individual particles oscillating within the trap and interacting pairwise with one another. In conclusion, we examine some representative instability scenarios of the multi-ring dynamics, including breakup and reconnections, as well as the transient formation of vortex lines.« less

Spin-Orbit-Coupled Interferometry with Ring-Trapped Bose-Einstein Condensates

NASA Astrophysics Data System (ADS)

Helm, J. L.; Billam, T. P.; Rakonjac, A.; Cornish, S. L.; Gardiner, S. A.

2018-02-01

We propose a method of atom interferometry using a spinor Bose-Einstein condensate with a time-varying magnetic field acting as a coherent beam splitter. Our protocol creates long-lived superpositional counterflow states, which are of fundamental interest and can be made sensitive to both the Sagnac effect and magnetic fields on the sub-μ G scale. We split a ring-trapped condensate, initially in the mf=0 hyperfine state, into superpositions of internal mf=±1 states and condensate superflow, which are spin-orbit coupled. After interrogation, the relative phase accumulation can be inferred from a population transfer to the mf=±1 states. The counterflow generation protocol is adiabatically deterministic and does not rely on coupling to additional optical fields or mechanical stirring techniques. Our protocol can maximize the classical Fisher information for any rotation, magnetic field, or interrogation time and so has the maximum sensitivity available to uncorrelated particles. Precision can increase with the interrogation time and so is limited only by the lifetime of the condensate.

All-Versus-Nothing Proof of Einstein-Podolsky-Rosen Steering

PubMed Central

Chen, Jing-Ling; Ye, Xiang-Jun; Wu, Chunfeng; Su, Hong-Yi; Cabello, Adán; Kwek, L. C.; Oh, C. H.

2013-01-01

Einstein-Podolsky-Rosen steering is a form of quantum nonlocality intermediate between entanglement and Bell nonlocality. Although Schrödinger already mooted the idea in 1935, steering still defies a complete understanding. In analogy to “all-versus-nothing” proofs of Bell nonlocality, here we present a proof of steering without inequalities rendering the detection of correlations leading to a violation of steering inequalities unnecessary. We show that, given any two-qubit entangled state, the existence of certain projective measurement by Alice so that Bob's normalized conditional states can be regarded as two different pure states provides a criterion for Alice-to-Bob steerability. A steering inequality equivalent to the all-versus-nothing proof is also obtained. Our result clearly demonstrates that there exist many quantum states which do not violate any previously known steering inequality but are indeed steerable. Our method offers advantages over the existing methods for experimentally testing steerability, and sheds new light on the asymmetric steering problem. PMID:23828242

Quantum fluctuations and gapped Goldstone modes in spinor Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Beekman, Aron

2015-03-01

The classical Heisenberg ferromagnet is an exact eigenstate of the quantum Hamiltonian and therefore has no quantum fluctuations. Furthermore it has a reduced number of Goldstone modes, an order parameter that is itself a symmetry generator, is a highest-weight state for the spin algebra, and has no tower of states of vanishing energy. We derive the connection between all these properties and provide general criteria for their presence in other spontaneously-broken symmetry states. The phletora of groundstates in spinor Bose-Einstein condensates is an ideal testing ground for these predictions. In particular the phases with non-maximal polarization (e.g. the F-phase in spin-3 condensates) have an additional gapped mode that is a partner to the quadratically dispersing Goldstone mode, as compared to the maximally polarized, ferromagnetic phase. Furthermore there is a fundamental limit to the coherence time of superpositions in the non-maximally polarized state, which should manifest itself for small-size systems.

Single and multiple vortex rings in three-dimensional Bose-Einstein condensates: Existence, stability, and dynamics

DOE PAGES

Wang, Wenlong; Bisset, R. N.; Ticknor, Christopher; ...

2017-04-27

In the present work, we explore the existence, stability, and dynamics of single- and multiple-vortex-ring states that can arise in Bose-Einstein condensates. Earlier works have illustrated the bifurcation of such states in the vicinity of the linear limit for isotropic or anisotropic three-dimensional harmonic traps. Here, we extend these states to the regime of large chemical potentials, the so-called Thomas-Fermi limit, and explore their properties such as equilibrium radii and inter-ring distance for multi-ring states, as well as their vibrational spectra and possible instabilities. In this limit, both the existence and stability characteristics can be partially traced to a particlemore » picture that considers the rings as individual particles oscillating within the trap and interacting pairwise with one another. In conclusion, we examine some representative instability scenarios of the multi-ring dynamics, including breakup and reconnections, as well as the transient formation of vortex lines.« less

Cosmic transit and anisotropic models in f(R,T) gravity

NASA Astrophysics Data System (ADS)

Sahu, S. K.; Tripathy, S. K.; Sahoo, P. K.; Nath, A.

2017-06-01

Accelerating cosmological models are constructed in a modified gravity theory dubbed as $f(R,T)$ gravity at the backdrop of an anisotropic Bianchi type-III universe. $f(R,T)$ is a function of the Ricci scalar $R$ and the trace $T$ of the energy-momentum tensor and it replaces the Ricci scalar in the Einstein-Hilbert action of General Relativity. The models are constructed for two different ways of modification of the Einstein-Hilbert action. Exact solutions of the field equations are obtained by a novel method of integration. We have explored the behaviour of the cosmic transit from an decelerated phase of expansion to an accelerated phase to get the dynamical features of the universe. Within the formalism of the present work, it is found that, the modification of the Einstein-Hilbert action does not affect the scale factor. However the dynamics of the effective dark energy equation of state is significantly affected.

Black hole dynamics in Einstein-Maxwell-dilaton theory

NASA Astrophysics Data System (ADS)

Hirschmann, Eric W.; Lehner, Luis; Liebling, Steven L.; Palenzuela, Carlos

2018-03-01

We consider the properties and dynamics of black holes within a family of alternative theories of gravity, namely Einstein-Maxwell-dilaton theory. We analyze the dynamical evolution of individual black holes as well as the merger of binary black hole systems. We do this for a wide range of parameter values for the family of Einstein-Maxwell-dilaton theories, investigating, in the process, the stability of these black holes. We examine radiative degrees of freedom, explore the impact of the scalar field on the dynamics of merger, and compare with other scalar-tensor theories. We argue that the dilaton can largely be discounted in understanding merging binary systems and that the end states essentially interpolate between charged and uncharged, rotating black holes. For the relatively small charge values considered here, we conclude that these black hole systems will be difficult to distinguish from their analogs within General Relativity.

Inverse engineering for fast transport and spin control of spin-orbit-coupled Bose-Einstein condensates in moving harmonic traps

NASA Astrophysics Data System (ADS)

Chen, Xi; Jiang, Ruan-Lei; Li, Jing; Ban, Yue; Sherman, E. Ya.

2018-01-01

We investigate fast transport and spin manipulation of tunable spin-orbit-coupled Bose-Einstein condensates in a moving harmonic trap. Motivated by the concept of shortcuts to adiabaticity, we design inversely the time-dependent trap position and spin-orbit-coupling strength. By choosing appropriate boundary conditions we obtain fast transport and spin flip simultaneously. The nonadiabatic transport and relevant spin dynamics are illustrated with numerical examples and compared with the adiabatic transport with constant spin-orbit-coupling strength and velocity. Moreover, the influence of nonlinearity induced by interatomic interaction is discussed in terms of the Gross-Pitaevskii approach, showing the robustness of the proposed protocols. With the state-of-the-art experiments, such an inverse engineering technique paves the way for coherent control of spin-orbit-coupled Bose-Einstein condensates in harmonic traps.

Einstein's Years in Switzerland

NASA Astrophysics Data System (ADS)

Plendl, Hans S.

2005-11-01

Albert Einstein left Germany, the country of his birth, in 1894 and moved to Switzerland in 1895. He studied, worked and taught there, except for a year's stay in Prague, until1914. That year he returned to Germany, where he lived until his emigration to the United States in 1933. In 1905, while living with his wife Mileva and their first son Hans Albert in Bern and working as a technical expert at the Swiss Patent Office, he published his dissertation on the determination of molecular dimensions, his papers on Brownian Motion that helped to establish the Kinetic Theory of Heat and on the Photo-Electric Effect that validated the Quantum Theory of Light, and the two papers introducing the Special Theory of Relativity. How the young Einstein could help to lay the foundations of these theories while still working on his dissertation, holding a full-time job and helping to raise a family has evoked much discussion among his biographers. In this contribution, the extent to which living within Swiss society and culture could have made this feat possible will be examined. Old and recent photos of places in Switzerland where Einstein has lived and worked will be shown.

Generating a fractal butterfly Floquet spectrum in a class of driven SU(2) systems

NASA Astrophysics Data System (ADS)

Wang, Jiao; Gong, Jiangbin

2010-02-01

A scheme for generating a fractal butterfly Floquet spectrum, first proposed by Wang and Gong [Phys. Rev. A 77, 031405(R) (2008)], is extended to driven SU(2) systems such as a driven two-mode Bose-Einstein condensate. A class of driven systems without a link with the Harper-model context is shown to have an intriguing butterfly Floquet spectrum. The found butterfly spectrum shows remarkable deviations from the known Hofstadter’s butterfly. In addition, the level crossings between Floquet states of the same parity and between Floquet states of different parities are studied and highlighted. The results are relevant to studies of fractal statistics, quantum chaos, and coherent destruction of tunneling, as well as the validity of mean-field descriptions of Bose-Einstein condensates.

Bose-Einstein condensation on a manifold with non-negative Ricci curvature

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

Akant, Levent, E-mail: levent.akant@boun.edu.tr; Ertuğrul, Emine, E-mail: emine.ertugrul@boun.edu.tr; Tapramaz, Ferzan, E-mail: waskhez@gmail.com

The Bose-Einstein condensation for an ideal Bose gas and for a dilute weakly interacting Bose gas in a manifold with non-negative Ricci curvature is investigated using the heat kernel and eigenvalue estimates of the Laplace operator. The main focus is on the nonrelativistic gas. However, special relativistic ideal gas is also discussed. The thermodynamic limit of the heat kernel and eigenvalue estimates is taken and the results are used to derive bounds for the depletion coefficient. In the case of a weakly interacting gas, Bogoliubov approximation is employed. The ground state is analyzed using heat kernel methods and finite sizemore » effects on the ground state energy are proposed. The justification of the c-number substitution on a manifold is given.« less

Spin-orbit-coupled Bose-Einstein condensates of rotating polar molecules

NASA Astrophysics Data System (ADS)

Deng, Y.; You, L.; Yi, S.

2018-05-01

An experimental proposal for realizing spin-orbit (SO) coupling of pseudospin 1 in the ground manifold 1Σ (υ =0 ) of (bosonic) bialkali polar molecules is presented. The three spin components are composed of the ground rotational state and two substates from the first excited rotational level. Using hyperfine resolved Raman processes through two select excited states resonantly coupled by a microwave, an effective coupling between the spin tensor and linear momentum is realized. The properties of Bose-Einstein condensates for such SO-coupled molecules exhibiting dipolar interactions are further explored. In addition to the SO-coupling-induced stripe structures, the singly and doubly quantized vortex phases are found to appear, implicating exciting opportunities for exploring novel quantum physics using SO-coupled rotating polar molecules with dipolar interactions.

Generating a fractal butterfly Floquet spectrum in a class of driven SU(2) systems

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

Wang Jiao; Temasek Laboratories, National University of Singapore, Singapore 117542; Gong Jiangbin

2010-02-15

A scheme for generating a fractal butterfly Floquet spectrum, first proposed by Wang and Gong [Phys. Rev. A 77, 031405(R) (2008)], is extended to driven SU(2) systems such as a driven two-mode Bose-Einstein condensate. A class of driven systems without a link with the Harper-model context is shown to have an intriguing butterfly Floquet spectrum. The found butterfly spectrum shows remarkable deviations from the known Hofstadter's butterfly. In addition, the level crossings between Floquet states of the same parity and between Floquet states of different parities are studied and highlighted. The results are relevant to studies of fractal statistics, quantummore » chaos, and coherent destruction of tunneling, as well as the validity of mean-field descriptions of Bose-Einstein condensates.« less

Matter scattering in quadratic gravity and unitarity

NASA Astrophysics Data System (ADS)

Abe, Yugo; Inami, Takeo; Izumi, Keisuke; Kitamura, Tomotaka

2018-03-01

We investigate the ultraviolet (UV) behavior of two-scalar elastic scattering with graviton exchanges in higher-curvature gravity theory. In Einstein gravity, matter scattering is shown not to satisfy the unitarity bound at tree level at high energy. Among some of the possible directions for the UV completion of Einstein gravity, such as string theory, modified gravity, and inclusion of high-mass/high-spin states, we take R_{μν}^2 gravity coupled to matter. We show that matter scattering with graviton interactions satisfies the unitarity bound at high energy, even with negative norm states due to the higher-order derivatives of metric components. The difference in the unitarity property of these two gravity theories is probably connected to that in another UV property, namely, the renormalizability property of the two.

Feshbach resonance management for Bose-Einstein condensates.

PubMed

Kevrekidis, P G; Theocharis, G; Frantzeskakis, D J; Malomed, Boris A

2003-06-13

An experimentally realizable scheme of periodic sign-changing modulation of the scattering length is proposed for Bose-Einstein condensates similar to dispersion-management schemes in fiber optics. Because of controlling the scattering length via the Feshbach resonance, the scheme is named Feshbach-resonance management. The modulational-instability analysis of the quasiuniform condensate driven by this scheme leads to an analog of the Kronig-Penney model. The ensuing stable localized structures are found. These include breathers, which oscillate between the Thomas-Fermi and Gaussian configuration, or may be similar to the 2-soliton state of the nonlinear Schrödinger equation, and a nearly static state ("odd soliton") with a nested dark soliton. An overall phase diagram for breathers is constructed, and full stability of the odd solitons is numerically established.

Absence of Jahn-Teller transition in the hexagonal Ba 3CuSb 2O 9 single crystal

DOE PAGES

Katayama, Naoyuki; Kimura, Kenta; Han, Yibo; ...

2015-07-13

With decreasing temperature, liquids generally freeze into a solid state, losing entropy in the process. However, exceptions to this trend exist, such as quantum liquids, which may remain unfrozen down to absolute zero owing to strong quantum entanglement effects that stabilize a disordered state with zero entropy. Examples of such liquids include Bose-Einstein condensation of cold atoms, superconductivity, quantum Hall state of electron systems, and quantum spin liquid state in the frustrated magnets. Furthermore, recent studies have clarified the possibility of another exotic quantum liquid state based on the spin-orbital entanglement in FeSc2S4. To confirm this exotic ground state, experimentsmore » based on single-crystalline samples are essential. However, no such single-crystal study has been reported to date. Here, we report, to our knowledge, the first single-crystal study on the spin-orbital liquid candidate, 6H-Ba3CuSb2O9, and we have confirmed the absence of an orbital frozen state. In strongly correlated electron systems, orbital ordering usually appears at high temperatures in a process accompanied by a lattice deformation, called a static Jahn-Teller distortion. By combining synchrotron X-ray diffraction, electron spin resonance, Raman spectroscopy, and ultrasound measurements, we find that the static Jahn-Teller distortion is absent in the present material, which indicates that orbital ordering is suppressed down to the lowest temperatures measured. Lastly, we discuss how such an unusual feature is realized with the help of spin degree of freedom, leading to a spin-orbital entangled quantum liquid state.« less

Two copies of the Einstein-Podolsky-Rosen state of light lead to refutation of EPR ideas.

PubMed

Rosołek, Krzysztof; Stobińska, Magdalena; Wieśniak, Marcin; Żukowski, Marek

2015-03-13

Bell's theorem applies to the normalizable approximations of original Einstein-Podolsky-Rosen (EPR) state. The constructions of the proof require measurements difficult to perform, and dichotomic observables. By noticing the fact that the four mode squeezed vacuum state produced in type II down-conversion can be seen both as two copies of approximate EPR states, and also as a kind of polarization supersinglet, we show a straightforward way to test violations of the EPR concepts with direct use of their state. The observables involved are simply photon numbers at outputs of polarizing beam splitters. Suitable chained Bell inequalities are based on the geometric concept of distance. For a few settings they are potentially a new tool for quantum information applications, involving observables of a nondichotomic nature, and thus of higher informational capacity. In the limit of infinitely many settings we get a Greenberger-Horne-Zeilinger-type contradiction: EPR reasoning points to a correlation, while quantum prediction is an anticorrelation. Violations of the inequalities are fully resistant to multipair emissions in Bell experiments using parametric down-conversion sources.

Einstein and Einstein A: A Study in Crater Morphology

NASA Image and Video Library

2017-12-08

NASA image release May 14, 2010 Einstein and Einstein A: A Study in Crater Morphology Located on the western limb of the Moon, Einstein and Einstein A craters (16.3oN, 271.3oE ) are only visible to Earth-based observers during certain lunar lighting and orientation conditions. Einstein A is younger than Einstein, as indicated by the fact that it lies squarely in the middle of the floor of Einstein. When viewed in topographic data, these two craters reveal much about the relative age and shape of an impact crater. To understand further, let's first take a look at Einstein. Einstein is a fairly large crater that spans 198 km across. A crater's size alone however cannot reveal much about age. ÊEinstein's relative age can be determined by examining the frequency and distribution of impact craters overprinted on its rim and floor. Younger craters have had fewer impacts, which enables them to retain their original morphology. Einstein A reveals most of its original structure, including a raised rim and ejecta blanket, and is therefore a relatively young crater as compared to Einstein, whose original structure has been somewhat degraded over time by smaller impacts. The Einstein craters were named after famed physicist, philosopher, and scientist Albert Einstein (1879-1955). To learn more go to: www.nasa.gov/mission_pages/LRO/multimedia/lroimages/lola-... NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Freud's superpotential in general relativity and in Einstein-Cartan theory

NASA Astrophysics Data System (ADS)

Böhmer, Christian G.; Hehl, Friedrich W.

2018-02-01

The identification of a suitable gravitational energy in theories of gravity has a long history, and it is well known that a unique answer cannot be given. In the first part of this paper we present a streamlined version of the derivation of Freud's superpotential in general relativity. It is found if we once integrate the gravitational field equation by parts. This allows us to extend these results directly to the Einstein-Cartan theory. Interestingly, Freud's original expression, first stated in 1939, remains valid even when considering gravitational theories in Riemann-Cartan or, more generally, in metric-affine spacetimes.

Anisotropic properties of phase separation in two-component dipolar Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Wang, Wei; Li, Jinbin

2018-03-01

Using Crank-Nicolson method, we calculate ground state wave functions of two-component dipolar Bose-Einstein condensates (BECs) and show that, due to dipole-dipole interaction (DDI), the condensate mixture displays anisotropic phase separation. The effects of DDI, inter-component s-wave scattering, strength of trap potential and particle numbers on the density profiles are investigated. Three types of two-component profiles are present, first cigar, along z-axis and concentric torus, second pancake (or blood cell), in xy-plane, and two non-uniform ellipsoid, separated by the pancake and third two dumbbell shapes.

Stable vortex-bright-soliton structures in two-component Bose-Einstein condensates.

PubMed

Law, K J H; Kevrekidis, P G; Tuckerman, Laurette S

2010-10-15

We report the numerical realization of robust two-component structures in 2D and 3D Bose-Einstein condensates with nontrivial topological charge in one component. We identify a stable symbiotic state in which a higher-dimensional bright soliton exists even in a homogeneous setting with defocusing interactions, due to the effective potential created by a stable vortex in the other component. The resulting vortex-bright-solitons, generalizations of the recently experimentally observed dark-bright solitons, are found to be very robust both in the homogeneous medium and in the presence of external confinement.

Albert Einstein Distinguished Educator Fellowship Act of 1994. Hearing on S. 2104 To Establish within the National Laboratories of the Department of Energy a National Albert Einstein Distinguished Educator Fellowship Program, before the Subcommittee on Energy Research and Development of the Committee on Energy and Natural Resources. United States Senate, One Hundred Third Congress, Second Session.

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. Senate Committee on Energy and Natural Resources.

These hearings addressed proposed Bill S. 2104 to create a Department of Energy (DOE) fellowship program for math and science teachers that would provide them opportunities to work at DOE labs in order to enhance coordination and communication among the educational community, the Congress, and the Executive Agencies responsible for developing and…

Segregated nodal domains of two-dimensional multispecies Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Chang, Shu-Ming; Lin, Chang-Shou; Lin, Tai-Chia; Lin, Wen-Wei

2004-09-01

In this paper, we study the distribution of m segregated nodal domains of the m-mixture of Bose-Einstein condensates under positive and large repulsive scattering lengths. It is shown that components of positive bound states may repel each other and form segregated nodal domains as the repulsive scattering lengths go to infinity. Efficient numerical schemes are created to confirm our theoretical results and discover a new phenomenon called verticillate multiplying, i.e., the generation of multiple verticillate structures. In addition, our proposed Gauss-Seidel-type iteration method is very effective in that it converges linearly in 10-20 steps.

Gravity Before Einstein and Schwinger Before Gravity

NASA Astrophysics Data System (ADS)

Trimble, Virginia L.

2012-05-01

Julian Schwinger was a child prodigy, and Albert Einstein distinctly not; Schwinger had something like 73 graduate students, and Einstein very few. But both thought gravity was important. They were not, of course, the first, nor is the disagreement on how one should think about gravity that is being highlighted here the first such dispute. The talk will explore, first, several of the earlier dichotomies: was gravity capable of action at a distance (Newton), or was a transmitting ether required (many others). Did it act on everything or only on solids (an odd idea of the Herschels that fed into their ideas of solar structure and sunspots)? Did gravitational information require time for its transmission? Is the exponent of r precisely 2, or 2 plus a smidgeon (a suggestion by Simon Newcomb among others)? And so forth. Second, I will try to say something about Scwinger's lesser known early work and how it might have prefigured his "source theory," beginning with "On the Interaction of Several Electrons (the unpublished, 1934 "zeroth paper," whose title somewhat reminds one of "On the Dynamics of an Asteroid," through his days at Berkeley with Oppenheimer, Gerjuoy, and others, to his application of ideas from nuclear physics to radar and of radar engineering techniques to problems in nuclear physics. And folks who think good jobs are difficult to come by now might want to contemplate the couple of years Schwinger spent teaching elementary physics at Purdue before moving on to the MIT Rad Lab for war work.

Hanle model of a spin-orbit coupled Bose-Einstein condensate of excitons in semiconductor quantum wells

NASA Astrophysics Data System (ADS)

Andreev, S. V.; Nalitov, A. V.

2018-04-01

We present a theoretical model of a driven-dissipative spin-orbit coupled Bose-Einstein condensate of indirect excitons in semiconductor quantum wells (QW's). Our steady-state solution of the problem shares analogies with the Hanle effect in an optical orientation experiment. The role of the spin pump in our case is played by Bose-stimulated scattering into a linearly-polarized ground state and the depolarization occurs as a result of exchange interaction between electrons and holes. Our theory agrees with the recent experiment [A. A. High et al., Phys. Rev. Lett. 110, 246403 (2013), 10.1103/PhysRevLett.110.246403], where spontaneous emergence of spatial coherence and polarization textures have been observed. As a complementary test, we discuss a configuration where an external magnetic field is applied in the structure plane.

Feedback control of an interacting Bose-Einstein condensate using phase-contrast imaging

NASA Astrophysics Data System (ADS)

Szigeti, S. S.; Hush, M. R.; Carvalho, A. R. R.; Hope, J. J.

2010-10-01

The linewidth of an atom laser is limited by density fluctuations in the Bose-Einstein condensate (BEC) from which the atom laser beam is outcoupled. In this paper we show that a stable spatial mode for an interacting BEC can be generated using a realistic control scheme that includes the effects of the measurement backaction. This model extends the feedback theory, based on a phase-contrast imaging setup, presented by Szigeti, Hush, Carvalho, and Hope [Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.80.013614 80, 013614 (2009)]. In particular, it is applicable to a BEC with large interatomic interactions and solves the problem of inadequacy of the mean-field (coherent state) approximation by utilizing a fixed number state approximation. Our numerical analysis shows the control to be more effective for a condensate with a large nonlinearity.

Feedback control of an interacting Bose-Einstein condensate using phase-contrast imaging

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

Szigeti, S. S.; Hush, M. R.; Carvalho, A. R. R.

2010-10-15

The linewidth of an atom laser is limited by density fluctuations in the Bose-Einstein condensate (BEC) from which the atom laser beam is outcoupled. In this paper we show that a stable spatial mode for an interacting BEC can be generated using a realistic control scheme that includes the effects of the measurement backaction. This model extends the feedback theory, based on a phase-contrast imaging setup, presented by Szigeti, Hush, Carvalho, and Hope [Phys. Rev. A 80, 013614 (2009)]. In particular, it is applicable to a BEC with large interatomic interactions and solves the problem of inadequacy of the mean-fieldmore » (coherent state) approximation by utilizing a fixed number state approximation. Our numerical analysis shows the control to be more effective for a condensate with a large nonlinearity.« less

Hyperspherical lowest-order constrained-variational approximation to resonant Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Sze, M. W. C.; Sykes, A. G.; Blume, D.; Bohn, J. L.

2018-03-01

We study the ground-state properties of a system of N harmonically trapped bosons of mass m interacting with two-body contact interactions, from small to large scattering lengths. This is accomplished in a hyperspherical coordinate system that is flexible enough to describe both the overall scale of the gas and two-body correlations. By adapting the lowest-order constrained-variational method, we are able to semiquantitatively attain Bose-Einstein condensate ground-state energies even for gases with infinite scattering length. In the large-particle-number limit, our method provides analytical estimates for the energy per particle E0/N ≈2.5 N1 /3ℏ ω and two-body contact C2/N ≈16 N1 /6√{m ω /ℏ } for a Bose gas on resonance, where ω is the trap frequency.

Methods for Tier 2 Modeling Within the Training Range Environmental Evaluation and Characterization System

DTIC Science & Technology

2011-03-01

acre-yr, compared with 54 tons/acre-yr as computed with the Universal Soil Loss Equation ( USLE ). Thus, it appears that the Einstein and Brown equations... USLE that is already needed for soil erosion that exports aqueous phase (adsorbed and dissolved) MC. This will mean that solid phase MC will not affect...phase MC mass to soil mass b = soil dry bulk density, g/m3 A = AOI site area, m2 E = soil erosion rate as determined from the USLE , m/yr It is

The Coast Artillery Journal. Volume 91, Number 2, March-April 1948

DTIC Science & Technology

1948-04-01

composites of Newton, Maxwell and Einstein. From the efforts of this Army group, from a similar group in the U. S. Navy, in England, and later in the Office...would be far too heavy if solid, it is decided to make it hollow , with walls 1foot thick. The can- non required for such a projectile is, of course, too... hollow ball or shell, This would improve the mass-ratio further since the rocket as later redesigned in the novel, would have found itself would not have

The Einstein Dossiers: Science and Politics - Einstein's Berlin Period with an Appendix on Einstein's FBI File

NASA Astrophysics Data System (ADS)

Grundmann, Siegfried

In 1919 the Prussian Ministry of Science, Arts and Culture opened a dossier on "Einstein's Theory of Relativity." It was rediscovered by the author in 1961 and is used in conjunction with numerous other subsequently identified 'Einstein' files as the basis of this fascinating book. In particular, the author carefully scrutinizes Einstein's FBI file from 1950-55 against mostly unpublished material from European including Soviet sources and presents hitherto unknown documentation on Einstein's alleged contacts with the German Communist Party and the Comintern.

My Half-Hour with Einstein

NASA Astrophysics Data System (ADS)

Romer, Robert H.

2005-04-01

Midway during my first year as a Princeton graduate student (1952-53), I was given a letter of introduction to Einstein. Over a year later I finally worked up my courage to use it and -- as a result -- enjoyed a one-on-one conversation with him in the study of his home on Mercer Street. I will describe how my chance to meet Einstein arose and what I can remember of our memorable (to me if not to him) conversation. Among other things, we discussed the bomb, the new state of Israel, fossil horse brains, and evolution. (``Has there really been enough time for all those changes?'') We talked about the Einstein-Rosen-Podolsky problem - though not by that name, and I believe that it was the ``Bohm version'' that he asked me about. (``Do you really believe that if someone here measured the spin of an atom, it could affect the simultaneous measurement of the spin of another atom way over there?'') My major recollection is of my wish that I had been better prepared. As Ehrenfest once wrote: ``Nothing is shabbier than the feeling: now God has granted me the opportunity to meet this man, and I sat before him open-mouthed; how much I might have asked him -- but nothing at all occurred to me.''

Anyon black holes

NASA Astrophysics Data System (ADS)

Aghaei Abchouyeh, Maryam; Mirza, Behrouz; Karimi Takrami, Moein; Younesizadeh, Younes

2018-05-01

We propose a correspondence between an Anyon Van der Waals fluid and a (2 + 1) dimensional AdS black hole. Anyons are particles with intermediate statistics that interpolates between a Fermi-Dirac statistics and a Bose-Einstein one. A parameter α (0 < α < 1) characterizes this intermediate statistics of Anyons. The equation of state for the Anyon Van der Waals fluid shows that it has a quasi Fermi-Dirac statistics for α >αc, but a quasi Bose-Einstein statistics for α <αc. By defining a general form of the metric for the (2 + 1) dimensional AdS black hole and considering the temperature of the black hole to be equal with that of the Anyon Van der Waals fluid, we construct the exact form of the metric for a (2 + 1) dimensional AdS black hole. The thermodynamic properties of this black hole is consistent with those of the Anyon Van der Waals fluid. For α <αc, the solution exhibits a quasi Bose-Einstein statistics. For α >αc and a range of values of the cosmological constant, there is, however, no event horizon so there is no black hole solution. Thus, for these values of cosmological constants, the AdS Anyon Van der Waals black holes have only quasi Bose-Einstein statistics.

Thermalization and confinement in strongly coupled gauge theories

NASA Astrophysics Data System (ADS)

Ishii, Takaaki; Kiritsis, Elias; Rosen, Christopher

2016-11-01

Quantum field theories of strongly interacting matter sometimes have a useful holographic description in terms of the variables of a gravitational theory in higher dimensions. This duality maps time dependent physics in the gauge theory to time dependent solutions of the Einstein equations in the gravity theory. In order to better understand the process by which "real world" theories such as QCD behave out of thermodynamic equilibrium, we study time dependent perturbations to states in a model of a confining, strongly coupled gauge theory via holography. Operationally, this involves solving a set of non-linear Einstein equations supplemented with specific time dependent boundary conditions. The resulting solutions allow one to comment on the timescale by which the perturbed states thermalize, as well as to quantify the properties of the final state as a function of the perturbation parameters. We comment on the influence of the dual gauge theory's confinement scale on these results, as well as the appearance of a previously anticipated universal scaling regime in the "abrupt quench" limit.

Determination of diffusion coefficient in disordered organic semiconductors

NASA Astrophysics Data System (ADS)

Rani, Varsha; Sharma, Akanksha; Ghosh, Subhasis

2016-05-01

Charge carrier transport in organic semiconductors is dominated by positional and energetic disorder in Gaussian density of states (GDOS) and is characterized by hopping through localized states. Due to the immobilization of charge carriers in these localized states, significant non-uniform carrier distribution exists, resulting diffusive transport. A simple, nevertheless powerful technique to determine diffusion coefficient D in disordered organic semiconductors has been presented. Diffusion coefficients of charge carriers in two technologically important organic molecular semiconductors, Pentacene and copper phthalocyanine (CuPc) have been measured from current-voltage (J-V) characteristics of Al/Pentacene/Au and Al/CuPc/Au based Schottky diodes. Ideality factor g and carrier mobility μ have been calculated from the exponential and space charge limited region respectively of J-V characteristics. Classical Einstein relation is not valid in organic semiconductors due to energetic disorders in DOS. Using generalized Einstein relation, diffusion coefficients have been obtained to be 1.31×10-6 and 1.73×10-7 cm2/s for Pentacene and CuPc respectively.

Teleportation of Two-Mode Quantum State of Continuous Variables

NASA Astrophysics Data System (ADS)

Song, Tong-Qiang

2004-03-01

Using two Einstein-Podolsky-Rosen pair eigenstates |η> as quantum channels, we study the teleportation of two-mode quantum state of continuous variables. The project supported by Natural Science Foundation of Zhejiang Province of China and Open Foundation of Laboratory of High-Intensity Optics, Shanghai Institute of Optics and Fine Mechanics

Einstein's Symphony: A Gravitational Wave Voyage Through Space and Time

NASA Astrophysics Data System (ADS)

Shapiro Key, Joey; Yunes, Nico; Grimberg, Irene

2015-01-01

Einstein's Symphony: A Gravitational Wave Voyage Through Space and Time is a gravitational wave astronomy planetarium show in production by a collaboration of scientists, filmmakers, and artisits from the Center for Gravitational Wave Astonomy (CGWA) at the University of Texas at Brownsville (UTB) and Montana State University (MSU). The project builds on the success of the interdisciplinary Celebrating Einstein collaboration. The artists and scientists who created the A Shout Across Time original film and the Black (W)hole immersive art installation for Celebrating Einstein are teaming with the Museum of the Rockies Taylor Planetarium staff and students to create a new full dome Digistar planetarium show that will be freely and widely distributed to planetaria in the US and abroad. The show uses images and animations filmed and collected for A Shout Across Time and for Black (W)hole as well as new images and animations and a new soundtrack composed and produced by the MSU School of Music to use the full capability of planetarium sound systems. The planetarium show will be narrated with ideas drawn from the Celebrating Einstein danced lecture on gravitational waves that the collaboration produced. The combination of products, resources, and team members assembled for this project allows us to create an original planetarium show for a fraction of the cost of a typical show. In addition, STEM education materials for G6-12 students and teachers will be provided to complement and support the show. This project is supported by the Texas Space Grant Consortium (TSGC), Montana Space Grant Consortium (MSGC), and the American Physical Society (APS).

The Stokes-Einstein relationship and the levitation effect: size-dependent diffusion maximum in dense fluids and close-packed disordered solids.

PubMed

Ghorai, Pradip Kr; Yashonath, S

2005-03-31

We report a molecular dynamics study of a binary mixture consisting of a large (host) particle and a smaller (guest) particle whose radius is varied over a range. These simulations investigate the possible existence of a diffusion anomaly or levitation effect in dense fluids, previously seen for guest molecules diffusing within porous solids. The voids in the larger component have been characterized in terms of void and neck distributions by means of Voronoi polyhedral analysis. Four different mixtures with differing ratios of guest to host diffusivities (D) have been studied. The results suggest that the diffusion anomaly is seen in both close-packed solids with disorder and dense fluids. In the latter, the void network is constantly and dynamically changing and possesses a considerable degree of disorder. The two regimes, viz., the linear regime (LR) and the anomalous regime (AR), found for porous solids are shown to exist for a dense medium as well. The linear regime is characterized by D(g) proportional to 1/sigma(gg)(2), where sigma(gg) is the diameter of the guest. The anomalous regime exhibits a maximum in D up to rather high temperatures (T = 1.663), even though in porous solids the maximum disappears at higher temperatures. In agreement with previous studies on porous solids, a particle in the AR is associated with lower activation energy, lower friction, and less backscattering in the velocity autocorrelation function when compared to a particle in the LR. Wavevector dependent self-diffusivity, Delta, and decay of the intermediate scattering function, F(s)(k, t), exhibit contrasting behaviors for the LR and AR. For LR, Delta exhibits a minimum at values of k at which there are spatial correlations in S(k) while a smooth decrease with k is seen for AR. For LR, F(s)(k, t) shows a biexponential decay corresponding to two different time scales of motion. Probably, the fast decay is associated with motion within the first shell of solvent neighbors and the slow decay with motion past these shells. For AR, a single-exponential decay is seen. The results indicate a breakdown of the Stokes-Einstein (SE) relationship. The relevant quantity that determines the validity of the SE relationship is the levitation parameter which is indirectly related to the solute/solvent radius ratio and not either the size of the solute or the solvent alone.

Developing density functional theory for Bose-Einstein condensates. The case of chemical bonding

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

Putz, Mihai V., E-mail: mvputz@cbg.uvt.ro

Since the nowadays growing interest in Bose-Einstein condensates due to the expanded experimental evidence on various atomic systems within optical lattices in weak and strong coupling regimes, the connection with Density Functional Theory is firstly advanced within the mean field framework at three levels of comprehension: the many-body normalization condition, Thomas-Fermi limit, and the chemical hardness closure with the inter-bosonic strength and universal Hohenberg-Kohn functional. As an application the traditional Heitler-London quantum mechanical description of the chemical bonding for homopolar atomic systems is reloaded within the non-linear Schrödinger (Gross-Pitaevsky) Hamiltonian; the results show that a two-fold energetic solution is registeredmore » either for bonding and antibonding states, with the bosonic contribution being driven by the square of the order parameter for the Bose-Einstein condensate density in free (gas) motion, while the associate wave functions remain as in classical molecular orbital model.« less

Bose-Einstein condensation of spin wave quanta at room temperature.

PubMed

Dzyapko, O; Demidov, V E; Melkov, G A; Demokritov, S O

2011-09-28

Spin waves are delocalized excitations of magnetic media that mainly determine their magnetic dynamics and thermodynamics at temperatures far below the critical one. The quantum-mechanical counterparts of spin waves are magnons, which can be considered as a gas of weakly interacting bosonic quasi-particles. Here, we discuss the room-temperature kinetics and thermodynamics of the magnon gas in yttrium iron garnet films driven by parametric microwave pumping. We show that for high enough pumping powers, the thermalization of the driven gas results in a quasi-equilibrium state described by Bose-Einstein statistics with a non-zero chemical potential. Further increases of the pumping power cause a Bose-Einstein condensation documented by an observation of the magnon accumulation at the lowest energy level. Using the sensitivity of the Brillouin light scattering spectroscopy to the degree of coherence of the scattering magnons, we confirm the spontaneous emergence of coherence of the magnons accumulated at the bottom of the spectrum, occurring if their density exceeds a critical value.

Delayed collapses of Bose-Einstein condensates in relation to anti-de Sitter gravity.

PubMed

Biasi, Anxo F; Mas, Javier; Paredes, Angel

2017-03-01

We numerically investigate spherically symmetric collapses in the Gross-Pitaevskii equation with attractive nonlinearity in a harmonic potential. Even below threshold for direct collapse, the wave function bounces off from the origin and may eventually become singular after a number of oscillations in the trapping potential. This is reminiscent of the evolution of Einstein gravity sourced by a scalar field in anti de Sitter space where collapse corresponds to black-hole formation. We carefully examine the long time evolution of the wave function for continuous families of initial states in order to sharpen out this qualitative coincidence which may bring new insights in both directions. On the one hand, we comment on possible implications for the so-called Bosenova collapses in cold atom Bose-Einstein condensates. On the other hand, Gross-Pitaevskii provides a toy model to study the relevance of either the resonance conditions or the nonlinearity for the problem of anti de Sitter instability.

Localized nonlinear waves and dynamical stability in spinor Bose–Einstein condensates with time–space modulation

NASA Astrophysics Data System (ADS)

Yao, Yu-Qin; Han, Wei; Li, Ji; Liu, Wu-Ming

2018-05-01

Nonlinearity is one of the most remarkable characteristics of Bose–Einstein condensates (BECs). Much work has been done on one- and two-component BECs with time- or space-modulated nonlinearities, while there is little work on spinor BECs with space–time-modulated nonlinearities. In the present paper we investigate localized nonlinear waves and dynamical stability in spinor Bose–Einstein condensates with nonlinearities dependent on time and space. We solve the three coupled Gross–Pitaevskii equations by similarity transformation and obtain two families of exact matter wave solutions in terms of Jacobi elliptic functions and the Mathieu equation. The localized states of the spinor matter wave describe the dynamics of vector breathing solitons, moving breathing solitons, quasi-breathing solitons and resonant solitons. The results show that one-order vector breathing solitons, quasi-breathing solitons, resonant solitons and the moving breathing solitons ψ ±1 are all stable, but the moving breathing soliton ψ 0 is unstable. We also present the experimental parameters to realize these phenomena in future experiments.

Well-posedness of the Einstein-Euler system in asymptotically flat spacetimes: The constraint equations

NASA Astrophysics Data System (ADS)

Brauer, Uwe; Karp, Lavi

This paper deals with the construction of initial data for the coupled Einstein-Euler system. We consider the condition where the energy density might vanish or tend to zero at infinity, and where the pressure is a fractional power of the energy density. In order to achieve our goals we use a type of weighted Sobolev space of fractional order. The common Lichnerowicz-York scaling method (Choquet-Bruhat and York, 1980 [9]; Cantor, 1979 [7]) for solving the constraint equations cannot be applied here directly. The basic problem is that the matter sources are scaled conformally and the fluid variables have to be recovered from the conformally transformed matter sources. This problem has been addressed, although in a different context, by Dain and Nagy (2002) [11]. We show that if the matter variables are restricted to a certain region, then the Einstein constraint equations have a unique solution in the weighted Sobolev spaces of fractional order. The regularity depends upon the fractional power of the equation of state.

Einstein and Besso: Not a Partnership of Equals

NASA Astrophysics Data System (ADS)

Janssen, Michel

2005-04-01

In the 1905 special relativity paper Einstein famously acknowledged the help of his friend and colleague Michele Besso. Besso had been an ideal sounding board for Einstein's ideas. During the years that Einstein developed general relativity, Besso was a good deal more than a sounding board. He collaborated with Einstein on calculations of the perihelion motion of Mercury in 1913. His contributions were substantial and would have warranted co-authorship of Einstein's famous paper on Mercury's perihelion of November 1915, in which Besso is not mentioned at all. Besso also alerted Einstein to problems with the early version of general relativity that Einstein had worked out together with Marcel Grossmann. Einstein essentially ignored Besso's warnings. In addition, Besso went out of his way during this period to act as a mediator between a not always appreciative Einstein, living in Berlin with his cousin Elsa who would become his second wife, and his estranged first wife Mileva, living in Zurich with the couple's two young sons. This period is much better documented than the period leading up to the 1905 paper and consequently much more revealing about the nature of the relationship between Einstein and Besso.

Brownian motion of solitons in a Bose-Einstein condensate.

PubMed

Aycock, Lauren M; Hurst, Hilary M; Efimkin, Dmitry K; Genkina, Dina; Lu, Hsin-I; Galitski, Victor M; Spielman, I B

2017-03-07

We observed and controlled the Brownian motion of solitons. We launched solitonic excitations in highly elongated [Formula: see text] Bose-Einstein condensates (BECs) and showed that a dilute background of impurity atoms in a different internal state dramatically affects the soliton. With no impurities and in one dimension (1D), these solitons would have an infinite lifetime, a consequence of integrability. In our experiment, the added impurities scatter off the much larger soliton, contributing to its Brownian motion and decreasing its lifetime. We describe the soliton's diffusive behavior using a quasi-1D scattering theory of impurity atoms interacting with a soliton, giving diffusion coefficients consistent with experiment.

Experimental investigation of early-time diffusion in the quantum kicked rotor using a Bose-Einstein condensate.

PubMed

Duffy, G J; Parkins, S; Müller, T; Sadgrove, M; Leonhardt, R; Wilson, A C

2004-11-01

We report measurements of the early-time momentum diffusion for the atom-optical delta-kicked rotor. In this experiment a Bose-Einstein condensate provides a source of ultracold atoms with an ultranarrow initial momentum distribution, which is then subjected to periodic pulses (or "kicks") using an intense far-detuned optical standing wave. We characterize the effect of varying the effective Planck's constant for the system, while keeping all other parameters fixed. The observed behavior includes both quantum resonances (ballistic energy growth) and antiresonances (re-establishment of the initial state). Our experimental results are compared with theoretical predictions.

Brownian motion of solitons in a Bose–Einstein condensate

PubMed Central

Aycock, Lauren M.; Hurst, Hilary M.; Efimkin, Dmitry K.; Genkina, Dina; Lu, Hsin-I; Galitski, Victor M.; Spielman, I. B.

2017-01-01

We observed and controlled the Brownian motion of solitons. We launched solitonic excitations in highly elongated Rb87 Bose–Einstein condensates (BECs) and showed that a dilute background of impurity atoms in a different internal state dramatically affects the soliton. With no impurities and in one dimension (1D), these solitons would have an infinite lifetime, a consequence of integrability. In our experiment, the added impurities scatter off the much larger soliton, contributing to its Brownian motion and decreasing its lifetime. We describe the soliton’s diffusive behavior using a quasi-1D scattering theory of impurity atoms interacting with a soliton, giving diffusion coefficients consistent with experiment. PMID:28196896

Entanglement, Einstein-Podolsky-Rosen correlations, Bell nonlocality, and steering

NASA Astrophysics Data System (ADS)

Jones, S. J.; Wiseman, H. M.; Doherty, A. C.

2007-11-01

In a recent work [Phys. Rev. Lett. 98, 140402 (2007)] we defined “steering,” a type of quantum nonlocality that is logically distinct from both nonseparability and Bell nonlocality. In the bipartite setting, it hinges on the question of whether Alice can affect Bob’s state at a distance through her choice of measurement. More precisely and operationally, it hinges on the question of whether Alice, with classical communication, can convince Bob that they share an entangled state under the circumstances that Bob trusts nothing that Alice says. We argue that if she can, then this demonstrates the nonlocal effect first identified in the famous Einstein-Podolsky-Rosen paper [Phys. Rev. 47, 777 (1935)] as a universal effect for pure entangled states. This ability of Alice to remotely prepare Bob’s state was subsequently called steering by Schrödinger, whose terminology we adopt. The phenomenon of steering has been largely overlooked, and prior to our work had not even been given a rigorous definition that is applicable to mixed states as well as pure states. Armed with our rigorous definition, we proved that steerable states are a strict subset of the entangled states, and a strict superset of the states that can exhibit Bell nonlocality. In this work we expand on these results and provide further examples of steerable states. We also elaborate on the connection with the original EPR paradox.

Relativistic coupled-cluster and density-functional studies of argon at high pressure

NASA Astrophysics Data System (ADS)

Schwerdtfeger, Peter; Steenbergen, Krista G.; Pahl, Elke

2017-06-01

The equation of state P (V ,T ) for solid argon is determined by the calculation of accurate static and vibrational terms in the free energy. The static component comes from a quantum theoretical many-body expansion summing over all energetic contributions from two-, three-, and four-body fragments treated with relativistic coupled cluster theory, while the lattice vibrations are described at an anharmonic level including two- and three-body forces as well as temperature effects. The dynamic part is calculated within the Debye and Einstein approximation, as well as by a more accurate phonon treatment where the vibrational motions in the lattice are coupled. Our results are in good agreement with room-temperature high-pressure experimental data up to ˜20 GPa. In the 20-100 GPa pressure range, however, we see considerable deviations between experiment and theory, perhaps indicating missing four-body contributions (beyond the quadruple dipole terms included here), missing five and higher-body effects, and the need to go beyond the coupled cluster singles-doubles with perturbative triples treatment in such higher-body forces. This contrasts with the results for solid neon, where excellent agreement has been achieved taking only two- and three-body forces into account [P. Schwerdtfeger and A. Hermann, Phys. Rev. B 80, 064106 (2009), 10.1103/PhysRevB.80.064106]. We demonstrate that the phase transition from fcc to hcp cannot account for the large discrepancies observed. Density functional calculations give very mixed results in the high-pressure region, but some functionals such as optB88-vdW (proposed by Lundqvist and co-workers) describe the many-body forces in argon reasonably well over the range of pressures investigated. Theoretical investigations of the heavier rare gas solids reaching experimental accuracy in the high-pressure regime therefore remain a significant challenge.

Inflationary Quasiparticle Creation and Thermalization Dynamics in Coupled Bose-Einstein Condensates

NASA Astrophysics Data System (ADS)

Posazhennikova, Anna; Trujillo-Martinez, Mauricio; Kroha, Johann

2016-06-01

A Bose gas in a double-well potential, exhibiting a true Bose-Einstein condensate (BEC) amplitude and initially performing Josephson oscillations, is a prototype of an isolated, nonequilibrium many-body system. We investigate the quasiparticle (QP) creation and thermalization dynamics of this system by solving the time-dependent Keldysh-Bogoliubov equations. We find avalanchelike QP creation due to a parametric resonance between BEC and QP oscillations, followed by slow, exponential relaxation to a thermal state at an elevated temperature, controlled by the initial excitation energy of the oscillating BEC above its ground state. The crossover between the two regimes occurs because of an effective decoupling of the QP and BEC oscillations. This dynamics is analogous to elementary particle creation in models of the early universe. The thermalization in our setup occurs because the BEC acts as a grand canonical reservoir for the quasiparticle system.

Going Beyond Einstein with the Constellation-X Mission

NASA Technical Reports Server (NTRS)

White, Nicholas

2007-01-01

The Constellation-X mission will address the questions: "What happens to matter close to a black hole?" and "What is Dark Energy?" These questions are central to the NASA Beyond Einstein Program, where Constellation-X plays a central role. The mission will address these questions by using high throughput X-ray spectroscopy to observe the effects of strong gravity close to the event horizon of black holes, and to observe the formation and evolution of clusters of galaxies in order to precisely determine Cosmological parameters. To achieve these primary science goals requires a factor of 25-100 increase in sensitivity for high resolution X-ray spectroscopy.'The mission will also perform routine high-resolution X-ray spectroscopy of faint 2nd extended X-ray source populations. This will provide diagnostic information such as density, elemental abundances, velocity; and ionization state for a wide range of astrophysical problems, including new constraints on the Neutron Star equation of state.

Entropy Production Within a Pulsed Bose-Einstein Condensate

NASA Astrophysics Data System (ADS)

Heinisch, Christoph; Holthaus, Martin

2016-10-01

We suggest to subject anharmonically trapped Bose-Einstein condensates to sinusoidal forcing with a smooth, slowly changing envelope, and to measure the coherence of the system after such pulses. In a series of measurements with successively increased maximum forcing strength, one then expects an adiabatic return of the condensate to its initial state as long as the pulses remain sufficiently weak. In contrast, once the maximum driving amplitude exceeds a certain critical value there should be a drastic loss of coherence, reflecting significant heating induced by the pulse. This predicted experimental signature is traced to the loss of an effective adiabatic invariant, and to the ensuing breakdown of adiabatic motion of the system's Floquet state when the many-body dynamics become chaotic. Our scenario is illustrated with the help of a two-site model of a forced bosonic Josephson junction, but should also hold for other, experimentally accessible configurations.

Three-Component Soliton States in Spinor F =1 Bose-Einstein Condensates

NASA Astrophysics Data System (ADS)

Bersano, T. M.; Gokhroo, V.; Khamehchi, M. A.; D'Ambroise, J.; Frantzeskakis, D. J.; Engels, P.; Kevrekidis, P. G.

2018-02-01

Dilute-gas Bose-Einstein condensates are an exceptionally versatile test bed for the investigation of novel solitonic structures. While matter-wave solitons in one- and two-component systems have been the focus of intense research efforts, an extension to three components has never been attempted in experiments. Here, we experimentally demonstrate the existence of robust dark-bright-bright (DBB) and dark-dark-bright solitons in a multicomponent F =1 condensate. We observe lifetimes on the order of hundreds of milliseconds for these structures. Our theoretical analysis, based on a multiscale expansion method, shows that small-amplitude solitons of these types obey universal long-short wave resonant interaction models, namely, Yajima-Oikawa systems. Our experimental and analytical findings are corroborated by direct numerical simulations highlighting the persistence of, e.g., the DBB soliton states, as well as their robust oscillations in the trap.

Three-Component Soliton States in Spinor F=1 Bose-Einstein Condensates.

PubMed

Bersano, T M; Gokhroo, V; Khamehchi, M A; D'Ambroise, J; Frantzeskakis, D J; Engels, P; Kevrekidis, P G

2018-02-09

Dilute-gas Bose-Einstein condensates are an exceptionally versatile test bed for the investigation of novel solitonic structures. While matter-wave solitons in one- and two-component systems have been the focus of intense research efforts, an extension to three components has never been attempted in experiments. Here, we experimentally demonstrate the existence of robust dark-bright-bright (DBB) and dark-dark-bright solitons in a multicomponent F=1 condensate. We observe lifetimes on the order of hundreds of milliseconds for these structures. Our theoretical analysis, based on a multiscale expansion method, shows that small-amplitude solitons of these types obey universal long-short wave resonant interaction models, namely, Yajima-Oikawa systems. Our experimental and analytical findings are corroborated by direct numerical simulations highlighting the persistence of, e.g., the DBB soliton states, as well as their robust oscillations in the trap.

The role of prehealth student volunteers at a student-run free clinic in New York, United States.

PubMed

Shabbir, Syed H; Santos, Maria Teresa M

2015-01-01

The medical student-run Einstein Community Health Outreach Clinic provides free healthcare to the uninsured adult population of New York, the United States. During the summer, prehealth student volunteers are recruited to assist with clinic operations. We designed a survey study to identify the baseline characteristics of the volunteers between June and August of 2013 and 2014 in order to evaluate the influence of working in a medical student-run free clinic on their education, impressions, and career goals. A total of 38 volunteers (response rate, 83%) participated in the study. The volunteers were demographically diverse and interested in primary care specialties and community service. After the Einstein Community Health Outreach program, the volunteers showed an improved understanding of the healthcare process and issues relevant to uninsured patients. They also developed favorable attitudes towards primary care medicine and an increased level of interest in pursuing careers in primary care.

Inflationary Quasiparticle Creation and Thermalization Dynamics in Coupled Bose-Einstein Condensates.

PubMed

Posazhennikova, Anna; Trujillo-Martinez, Mauricio; Kroha, Johann

2016-06-03

A Bose gas in a double-well potential, exhibiting a true Bose-Einstein condensate (BEC) amplitude and initially performing Josephson oscillations, is a prototype of an isolated, nonequilibrium many-body system. We investigate the quasiparticle (QP) creation and thermalization dynamics of this system by solving the time-dependent Keldysh-Bogoliubov equations. We find avalanchelike QP creation due to a parametric resonance between BEC and QP oscillations, followed by slow, exponential relaxation to a thermal state at an elevated temperature, controlled by the initial excitation energy of the oscillating BEC above its ground state. The crossover between the two regimes occurs because of an effective decoupling of the QP and BEC oscillations. This dynamics is analogous to elementary particle creation in models of the early universe. The thermalization in our setup occurs because the BEC acts as a grand canonical reservoir for the quasiparticle system.

What about Albert Einstein? Using Biographies to Promote Students' Scientific Thinking

ERIC Educational Resources Information Center

Fingon, Joan C.; Fingon, Shallon D.

2009-01-01

Who hasn't heard of Einstein? Science educators everywhere are familiar with Einstein's genius and general theory of relativity. Students easily recognize Einstein's image by his white flyaway hair and bushy mustache. It is well known that Einstein was a brilliant physicist and an abstract thinker who often used his creativity and imagination in…

High-resolution X-ray spectroscopy of the supernova remnant N132D

NASA Technical Reports Server (NTRS)

Hwang, Una; Hughes, John P.; Canizares, Claude R.; Markert, Thomas H.

1993-01-01

A joint nonequilibrium ionization analysis of spectral data from the Einstein Observatory of the SNR N132D in the LMC is presented on the basis of data from the Focal Plane Crystal Spectrometer (FPCS) and the Solid State Spectrometer (SSS), and lower spectral resolution data from the IPC and the Monitor Proportional Counter (MPC). The FPCS detected individual emission lines of O VII, O VIII, Ne IX, Ne X, Fe XVII, and possibly Fe XX. Measured line widths for the oxygen lines suggest Doppler broadening that is roughly consistent with optically measured expansion velocities of 2250 km/s. At the SSS/IPC temperature, FPCS flux ratios constrain the O/Fe abundance to be at least 1.9 times its solar value and the O/Ne abundance to be 0.2-1.0 times its solar value. Models for remnants with progenitor masses of 20 and 25 solar masses are completely consistent with the data, while remnants with progenitor masses of 13 and 15 solar masses can be made consistent if the progenitors are required to eject a large fraction of their iron cores.

Two component X-ray emission from RS CVn binaries

NASA Technical Reports Server (NTRS)

Swank, J. H.; White, N. E.; Holt, S. S.; Becker, R. H.

1980-01-01

A summary of results from the solid state spectrometer on the Einstein Observatory for 7 RS CVn binaries is presented. The spectra of all require two emission components, evidenced by line emission characteristic of plasma at 4 to 8 x 10 to the 6th power and bremsstrahlung characteristic of 20 to 100 x 10 to the 6th power K. The data are interpreted in terms of magnetic coronal loops similar to those seen on the Sun, although with different characteristic parameters. The emission regions could be defined by separate magnetic structures. For pressure less than approximately 10 dynes/sq cm the low temperature plasma would be confined within the stellar radii, while the high temperature plasma would, for the synchronous close binaries, fill the binary orbits. However, for loop pressures exceeding 100 dynes/sq cm, the high temperature components would also be confined to within the stellar radii, in loops covering only small fractions of the stellar surfaces. While the radio properties and the occurrence of X-ray flares suggest the larger emission regions, the observations of time variations leave the ambiguity unresolved.

Spin polarized semimagnetic exciton-polariton condensate in magnetic field.

PubMed

Król, Mateusz; Mirek, Rafał; Lekenta, Katarzyna; Rousset, Jean-Guy; Stephan, Daniel; Nawrocki, Michał; Matuszewski, Michał; Szczytko, Jacek; Pacuski, Wojciech; Piętka, Barbara

2018-04-27

Owing to their integer spin, exciton-polaritons in microcavities can be used for observation of non-equilibrium Bose-Einstein condensation in solid state. However, spin-related phenomena of such condensates are difficult to explore due to the relatively small Zeeman effect of standard semiconductor microcavity systems and the strong tendency to sustain an equal population of two spin components, which precludes the observation of condensates with a well defined spin projection along the axis of the system. The enhancement of the Zeeman splitting can be achieved by introducing magnetic ions to the quantum wells, and consequently forming semimagnetic polaritons. In this system, increasing magnetic field can induce polariton condensation at constant excitation power. Here we evidence the spin polarization of a semimagnetic polaritons condensate exhibiting a circularly polarized emission over 95% even in a moderate magnetic field of about 3 T. Furthermore, we show that unlike nonmagnetic polaritons, an increase on excitation power results in an increase of the semimagnetic polaritons condensate spin polarization. These properties open new possibilities for testing theoretically predicted phenomena of spin polarized condensate.

Einstein's Cosmos (German Title: Einsteins Kosmos)

NASA Astrophysics Data System (ADS)

Duerbeck, Hilmar W.; Dick, Wolfgang R.

The different contributions of the present volume illuminate the interaction between Einstein and his colleagues when the foundations of modern cosmology were laid: First, the relativistic effects in the solar system, the gravitational redshift in the solar spectrum, and Einstein's relations with Freundlich and Eddington. Second, the cosmological models of Einstein, de Sitter, Friedmann, and Lemaître, which were discussed controversely till the end of the 1920s. Other scientists have also widened or critically questioned Einstein's insight and knowledge: Schwarzschild, Selety, Silberstein, and Mandl, whose life and work is discussed in separate articles. In those days, politics more than ever in history had influenced the lifes of scientists. Therefore, some comments on the ``political cosmos'' that has influenced decisively Einstein's life are also given. A special role in popularizing Einstein's world view was played by Archenhold Observatory in Berlin. A list of Einstein memorial places and a bibliographic list conclude the present book. All papers are written in German, and have English abstracts.

Shear-induced aggregation or disaggregation in edible oils: Models, computer simulation, and USAXS measurements

NASA Astrophysics Data System (ADS)

Townsend, B.; Peyronel, F.; Callaghan-Patrachar, N.; Quinn, B.; Marangoni, A. G.; Pink, D. A.

2017-12-01

The effects of shear upon the aggregation of solid objects formed from solid triacylglycerols (TAGs) immersed in liquid TAG oils were modeled using Dissipative Particle Dynamics (DPD) and the predictions compared to experimental data using Ultra-Small Angle X-ray Scattering (USAXS). The solid components were represented by spheres interacting via attractive van der Waals forces and short range repulsive forces. A velocity was applied to the liquid particles nearest to the boundary, and Lees-Edwards boundary conditions were used to transmit this motion to non-boundary layers via dissipative interactions. The shear was created through the dissipative forces acting between liquid particles. Translational diffusion was simulated, and the Stokes-Einstein equation was used to relate DPD length and time scales to SI units for comparison with USAXS results. The SI values depended on how large the spherical particles were (250 nm vs. 25 nm). Aggregation was studied by (a) computing the Structure Function and (b) quantifying the number of pairs of solid spheres formed. Solid aggregation was found to be enhanced by low shear rates. As the shear rate was increased, a transition shear region was manifested in which aggregation was inhibited and shear banding was observed. Aggregation was inhibited, and eventually eliminated, by further increases in the shear rate. The magnitude of the transition region shear, γ˙ t, depended on the size of the solid particles, which was confirmed experimentally.

BOOK REVIEW: Einsteins Kosmos. Untersuchungen zur Geschichte der Kosmologie Relativitatstheorie und zu Einsteins Wirken und Nachwirken

NASA Astrophysics Data System (ADS)

Sterken, C.; Duerbeck, H. W.; Dick, W. R.

2006-12-01

This book collects about 15 papers (most of them by one single author) on Einstein and the history of general relativity (GR) and the foundations of relativistic cosmology. The matter not only deals with Einstein and his times, but also with pre-GR ideas, and with the interplay of Einstein and his colleagues (opposing as well as supporting personalities). As the title indicates, all papers are written in German, but they include comprehensive Abstracts both in German and English. The book is illustrated with quite a number classical - but also some far more original though not less beautiful - photographs and facsimiles of documents. The book is edited very well, though the style of references is not quite homogeneous. There is no Index. K. Hentschel covers Einstein's argumentation for the existence of graviational redshift, and the initial search for empirical support. The error analysis of observational evidence supporting relativistic light deflection is discussed in a paper by P. Brosche. In particular, H. Duerbeck and P. Flin - in their description of the life and work of Silberstein, who was quite sceptic on the significance of the observational verifications a la Eddington - include the transcription of two most revealing letters by Silberstein to Sommerfeld (1919) and to Einstein (1934). In the first letter, Silberstein clearly shows his scientific maturity and integrity by scrutinising the observational evidence supporting light deflection, presented at a joint meeting of the Royal Society and the Royal Astronomical Society. The second letter, which is more a personal letter, includes lots of political references and connotations. Some of Einstein's political views are also revealed by D.B. Herrmann on the basis of his own correspondence with E.G. Straus, a collaborator of Einstein's. In a consequent paper, S. Grundmann gives remarks on Herrmann's contribution and illustrates Einstein's attitude towards Marx, Engels, Lenin and Stalin. M. Schemmel discusses Schwarzschild's cosmological speculations, and wonders why some people do immediately grasp the meaning and consequence of newly proposed doctrines, whereas the bulk of the contemporaneous scientists respond in a rather low profile. T. Jung reviews Einstein's contribution to cosmology, leading to the Friedmann-Einstein and Einstein-de Sitter universes (with a detailed Appendix on the Friedmann-Lemaitre cosmology), and also presents the cosmological work of Selety, and his correspondence with Einstein. In a subsequent paper, H.-J. Schmidt comments on Einstein's criticism on de Sitter's solution of the Einstein field equations. Controversies with Einstein are elaborated by G. Singer (on Friedmann) and by K. Roessler (on Lemaitre). J. Renn and T. Sauer discuss Mandl's role in the publication history of Einstein's papers, notably Einstein's short paper on gravitational lensing. Finally, the book concludes with a contribution by D.B. Herrmann about the relationship between Einstein and Archenhold Observatory (where Einstein gave his first Berlin popular lecture in 1915), the transcription of H.-J. Treder's 1979 public address at the Einstein memorial plaque, and an inventory list of about 50 Einstein memorabilia - monuments, busts, plaques - compiled by W.R. Dick. This book is based on ideas approached in a historical context from the individual perspective of the authors. It is a real treasure trove of information and basic references on the history of GR, and it also covers quite some grounds with mathematical equations.

Reassessing the Ritz-Einstein debate on the radiation asymmetry in classical electrodynamics

NASA Astrophysics Data System (ADS)

Frisch, Mathias; Pietsch, Wolfgang

2016-08-01

We investigate the debate between Walter Ritz and Albert Einstein on the origin and nature of the radiation asymmetry. We argue that Ritz's views on the radiation asymmetry were far richer and nuanced than the oft-cited joint letter with Einstein (Ritz & Einstein, 1909) suggests, and that Einstein's views in 1909 on the asymmetry are far more ambiguous than is commonly recognized. Indeed, there is strong evidence that Einstein ultimately came to agree with Ritz that elementary radiation processes in classical electrodynamics are non-symmetric and fully retarded.

BOOK REVIEW: Einstein's Jury: The Race to Test Relativity

NASA Astrophysics Data System (ADS)

Ehlers, Jürgen

2007-10-01

'I know very well that my theory rests on a shaky foundation. What attracts me to it is that it leads to consequences that seem to be accessible to experiment, and it provides a starting point for the theoretical understanding of gravitation', wrote Einstein in 1911. Einstein's Jury by Jeffrey Crelinsten—well documented, well written, and fascinating to read—describes how, from 1909 on, Einstein's two theories of relativity became known to astronomers, and how the predictions made between 1907 and 1915 were received as challenges to observers. The author gives a non-technical account of the efforts made until 1930 to test these predictions; he focuses on two of the three classical tests, namely gravitational redshift and bending of light; the 'jury' consists mainly of American observers—Adams, Campbell, Curtis, Hale, Perrin, St John, Trumpler and others—working with newly built large telescopes, and the Britons Eddington and Evershed. The major steps which, after a long struggle, convinced the majority of astronomers that Einstein was right, are narrated chronologically in rather great detail, especially the work at Lick Observatory, before and after the famous British observation of 1919, on solar eclipses, and the work at Mount Wilson and the Indian Kodaikanal Observatories to extract the gravitational redshift from the complicated spectrum of the sun. The account of the eclipse work which was carried out between 1918 and 1923 by Lick astronomers corrects the impression suggested by many historical accounts that the British expedition alone settled the light-bending question. Apart from these main topics, the anomalous perihelion advance of Mercury and the ether problem are covered. By concentrating on astronomy rather than on physics this book complements the rich but repetitive literature on Einstein and relativity which appeared in connection with the commemoration of Einstein's annus mirabilis, 2005. The well told stories include curiosities such as the Vulcan hypothesis, Evershed's Earth effect, and D C Miller's ether drift experiments. In particular, the sections on the history of the Californian observatories, their leading personalities, the differing attitudes of American and European scientists, and the influence of World War 1 on science, add interesting and informative aspects to the narrative. Those sections which report logistic and instrumental details of, for example, eclipse expeditions, were (to me) somewhat tiring. A weakness seems to be that the scientific importance of relativity problems is not stated clearly. On p43, the reader learns that Curtis quoted de Sitter's theoretical result of 7.15'' per century for Mercury's anomalous perihelion shift, but it is not mentioned that this value was due only to the special-relativistic variation of mass with velocity and already known to be much smaller than the observed value given on p88 and explained by general relativity, which includes, in particular, space curvature. In connection with light bending, the 'factor 2' is mentioned in several places without the explanation that this doubling is due to space curvature, the principal new effect whose observation created such a stir in 1919. Moreover, technical terms, for example absolute space, inertial frame, state of rest and (anomalous) dispersion, are used without explanation. Besides, readers interested as much in science as in its history would probably have appreciated a brief account of the present state of knowledge concerning the issues treated in this book and related ones. There are a few deplorable errors, for example the spectrum of the Andromeda nebula is shifted not towards the red, but towards the blue (p12); Eddington's limb deflection is given (p144) as 0.61'', while the correct value is 1.61''; misprints like that on p147 (coefficient of dr²), mistaking the astronomer Soldner (not Solden) for a physicist (p164). On p34 one reads 'Minkowski did not really grasp the physical implications of Einstein's work'—a strange judgment which contradicts the historical record. Thus readers looking for explanations of scientific statements in a historical context may be less satisfied. Those interested in the history and sociology of science, its organizations, the role of leading figures as well as their critics and the difficult process of how scientists establish 'facts', will enjoy reading this book and should profit from it. An 'Einstein's Jury' of today would have more evidence for a positive verdict, but also reasons for new skepticism.

Fate of a gray soliton in a quenched Bose-Einstein condensate

NASA Astrophysics Data System (ADS)

Gamayun, O.; Bezvershenko, Yu. V.; Cheianov, V.

2015-03-01

We investigate the destiny of a gray soliton in a repulsive one-dimensional Bose-Einstein condensate undergoing a sudden quench of the nonlinearity parameter. The outcome of the quench is found to depend dramatically on the ratio η of the final and initial values of the speed of sound. For integer η the soliton splits into exactly 2 η -1 solitons. For noninteger η the soliton decays into multiple solitons and Bogoliubov modes. The case of integer η is analyzed in detail. The parameters of solitons in the out state are found explicitly. Our approach exploits the inverse scattering method and can be easily used for similar quenches in any classical integrable system.

Strong binary pulsar constraints on Lorentz violation in gravity.

PubMed

Yagi, Kent; Blas, Diego; Yunes, Nicolás; Barausse, Enrico

2014-04-25

Binary pulsars are excellent laboratories to test the building blocks of Einstein's theory of general relativity. One of these is Lorentz symmetry, which states that physical phenomena appear the same for all inertially moving observers. We study the effect of violations of Lorentz symmetry in the orbital evolution of binary pulsars and find that it induces a much more rapid decay of the binary's orbital period due to the emission of dipolar radiation. The absence of such behavior in recent observations allows us to place the most stringent constraints on Lorentz violation in gravity, thus verifying one of the cornerstones of Einstein's theory much more accurately than any previous gravitational observation.

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

Gangadharan, Dhevan

Recent measurements have revealed a significant suppression of multipion Bose–Einstein correlations in heavy-ion collisions at the LHC. The suppression may be explained by postulating coherent pion emission. Typically, the suppression of Bose–Einstein correlations due to coherence is taken into account with the coherent state formalism in quantum optics. However, since charged pion correlations are most often measured, the additional constraint of isospin conservation, which is absent in quantum optics, needs to be taken into account. As a consequence, correlations emerge between pions of opposite charge. A calculation of the correlations induced by isospin conservation of coherent emission is made formore » two, three- and four-pion correlation functions and compared to the data from the LHC.« less

Monogamy of Einstein-Podolsky-Rosen Steering in the Background of an Asymptotically Flat Black Hole

NASA Astrophysics Data System (ADS)

Wang, Jieci; Jing, Jiliang; Fan, Heng

2018-03-01

We study the behavior of monogamy deficit and monogamy asymmetry for Einstein-Podolsky-Rosen steering of Gaussian states under the influence of the Hawking effect. We demonstrate that the monogamy of quantum steering shows an extreme scenario in the curved spacetime: the first part of a tripartite system cannot individually steer two other parties, but it can steer the collectivity of the remaining two parties. We also find that the monogamy deficit of Gaussian steering, a quantifier of genuine tripartite steering, are generated due to the influence of the Hawking thermal bath. Our results elucidate the structure of quantum steering in tripartite quantum systems in curved spacetime.

General method to predict voltage-dependent ionic conduction in a solid electrolyte coating on electrodes

NASA Astrophysics Data System (ADS)

Pan, Jie; Cheng, Yang-Tse; Qi, Yue

2015-04-01

Understanding the ionic conduction in solid electrolytes in contact with electrodes is vitally important to many applications, such as lithium ion batteries. The problem is complex because both the internal properties of the materials (e.g., electronic structure) and the characteristics of the externally contacting phases (e.g., voltage of the electrode) affect defect formation and transport. In this paper, we developed a method based on density functional theory to study the physics of defects in a solid electrolyte in equilibrium with an external environment. This method was then applied to predict the ionic conduction in lithium fluoride (LiF), in contact with different electrodes which serve as reservoirs with adjustable Li chemical potential (μLi) for defect formation. LiF was chosen because it is a major component in the solid electrolyte interphase (SEI) formed on lithium ion battery electrodes. Seventeen possible native defects with their relevant charge states in LiF were investigated to determine the dominant defect types on various electrodes. The diffusion barrier of dominant defects was calculated by the climbed nudged elastic band method. The ionic conductivity was then obtained from the concentration and mobility of defects using the Nernst-Einstein relationship. Three regions for defect formation were identified as a function of μLi: (1) intrinsic, (2) transitional, and (3) p -type region. In the intrinsic region (high μLi, typical for LiF on the negative electrode), the main defects are Schottky pairs and in the p -type region (low μLi, typical for LiF on the positive electrode) are Li ion vacancies. The ionic conductivity is calculated to be approximately 10-31Scm-1 when LiF is in contact with a negative electrode but it can increase to 10-12Scm-1 on a positive electrode. This insight suggests that divalent cation (e.g., Mg2+) doping is necessary to improve Li ion transport through the engineered LiF coating, especially for LiF on negative electrodes. Our results provide an understanding of the influence of the environment on defect formation and demonstrate a linkage between defect concentration in a solid electrolyte and the voltage of the electrode.

Bifurcation and stability of single and multiple vortex rings in three-dimensional Bose-Einstein condensates

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

Bisset, R. N.; Wang, Wenlong; Ticknor, C.

Here, we investigate how single- and multi-vortex-ring states can emerge from a planar dark soliton in three-dimensional (3D) Bose-Einstein condensates (confined in isotropic or anisotropic traps) through bifurcations. We characterize such bifurcations quantitatively using a Galerkin-type approach and find good qualitative and quantitative agreement with our Bogoliubov–de Gennes (BdG) analysis. We also systematically characterize the BdG spectrum of the dark solitons, using perturbation theory, and obtain a quantitative match with our 3D BdG numerical calculations. We then turn our attention to the emergence of single- and multi-vortex-ring states. We systematically capture these as stationary states of the system and quantifymore » their BdG spectra numerically. We found that although the vortex ring may be unstable when bifurcating, its instabilities weaken and may even eventually disappear for sufficiently large chemical potentials and suitable trap settings. For instance, we demonstrate the stability of the vortex ring for an isotropic trap in the large-chemical-potential regime.« less

Experimental Demonstration of the Einstein-Podolsky-Rosen Steering Game Based on the All-Versus-Nothing Proof

NASA Astrophysics Data System (ADS)

Sun, Kai; Xu, Jin-Shi; Ye, Xiang-Jun; Wu, Yu-Chun; Chen, Jing-Ling; Li, Chuan-Feng; Guo, Guang-Can

2014-10-01

Einstein-Podolsky-Rosen (EPR) steering, a generalization of the original concept of "steering" proposed by Schrödinger, describes the ability of one system to nonlocally affect another system's states through local measurements. Some experimental efforts to test EPR steering in terms of inequalities have been made, which usually require many measurement settings. Analogy to the "all-versus-nothing" (AVN) proof of Bell's theorem without inequalities, testing steerability without inequalities would be more strong and require less resources. Moreover, the practical meaning of steering implies that it should also be possible to store the state information on the side to be steered, a result that has not yet been experimentally demonstrated. Using a recent AVN criterion for two-qubit entangled states, we experimentally implement a practical steering game using quantum memory. Furthermore, we develop a theoretical method to deal with the noise and finite measurement statistics within the AVN framework and apply it to analyze the experimental data. Our results clearly show the facilitation of the AVN criterion for testing steerability and provide a particularly strong perspective for understanding EPR steering.

Robust and compact entanglement generation from diode-laser-pumped four-wave mixing

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

Lawrie, B. J.; Yang, Y.; Eaton, M.

Four-wave-mixing processes are now routinely used to demonstrate multi-spatial-mode Einstein- Podolsky-Rosen entanglement and intensity difference squeezing. Recently, diode-laser-pumped four-wave mixing processes have been shown to provide an affordable, compact, and stable source for intensity difference squeezing, but it was unknown if excess phase noise present in power amplifier pump configurations would be an impediment to achieving quadrature entanglement. Here, we demonstrate the operating regimes under which these systems are capable of producing entanglement and under which excess phase noise produced by the amplifier contaminates the output state. We show that Einstein-Podolsky-Rosen entanglement in two mode squeezed states can be generatedmore » by a four-wave-mixing source deriving both the pump field and the local oscillators from a tapered-amplifier diode-laser. In conclusion, this robust continuous variable entanglement source is highly scalable and amenable to miniaturization, making it a critical step toward the development of integrated quantum sensors and scalable quantum information processors, such as spatial comb cluster states.« less

Robust and compact entanglement generation from diode-laser-pumped four-wave mixing

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

Lawrie, B. J., E-mail: lawriebj@ornl.gov; Pooser, R. C.; Yang, Y.

Four-wave-mixing processes are now routinely used to demonstrate multi-spatial-mode Einstein-Podolsky-Rosen entanglement and intensity difference squeezing. Diode-laser-pumped four-wave mixing processes have recently been shown to provide an affordable, compact, and stable source for intensity difference squeezing, but it was unknown if excess phase noise present in power amplifier pump configurations would be an impediment to achieving quadrature entanglement. Here, we demonstrate the operating regimes under which these systems are capable of producing entanglement and under which excess phase noise produced by the amplifier contaminates the output state. We show that Einstein-Podolsky-Rosen entanglement in two mode squeezed states can be generated bymore » a four-wave-mixing source deriving both the pump field and the local oscillators from a tapered-amplifier diode-laser. This robust continuous variable entanglement source is highly scalable and amenable to miniaturization, making it a critical step toward the development of integrated quantum sensors and scalable quantum information processors, such as spatial comb cluster states.« less

Bifurcation and stability of single and multiple vortex rings in three-dimensional Bose-Einstein condensates

DOE PAGES

Bisset, R. N.; Wang, Wenlong; Ticknor, C.; ...

2015-10-01

Here, we investigate how single- and multi-vortex-ring states can emerge from a planar dark soliton in three-dimensional (3D) Bose-Einstein condensates (confined in isotropic or anisotropic traps) through bifurcations. We characterize such bifurcations quantitatively using a Galerkin-type approach and find good qualitative and quantitative agreement with our Bogoliubov–de Gennes (BdG) analysis. We also systematically characterize the BdG spectrum of the dark solitons, using perturbation theory, and obtain a quantitative match with our 3D BdG numerical calculations. We then turn our attention to the emergence of single- and multi-vortex-ring states. We systematically capture these as stationary states of the system and quantifymore » their BdG spectra numerically. We found that although the vortex ring may be unstable when bifurcating, its instabilities weaken and may even eventually disappear for sufficiently large chemical potentials and suitable trap settings. For instance, we demonstrate the stability of the vortex ring for an isotropic trap in the large-chemical-potential regime.« less

Robust and compact entanglement generation from diode-laser-pumped four-wave mixing

DOE PAGES

Lawrie, B. J.; Yang, Y.; Eaton, M.; ...

2016-04-11

Four-wave-mixing processes are now routinely used to demonstrate multi-spatial-mode Einstein- Podolsky-Rosen entanglement and intensity difference squeezing. Recently, diode-laser-pumped four-wave mixing processes have been shown to provide an affordable, compact, and stable source for intensity difference squeezing, but it was unknown if excess phase noise present in power amplifier pump configurations would be an impediment to achieving quadrature entanglement. Here, we demonstrate the operating regimes under which these systems are capable of producing entanglement and under which excess phase noise produced by the amplifier contaminates the output state. We show that Einstein-Podolsky-Rosen entanglement in two mode squeezed states can be generatedmore » by a four-wave-mixing source deriving both the pump field and the local oscillators from a tapered-amplifier diode-laser. In conclusion, this robust continuous variable entanglement source is highly scalable and amenable to miniaturization, making it a critical step toward the development of integrated quantum sensors and scalable quantum information processors, such as spatial comb cluster states.« less

In the limelight of stars. Einstein, Mandl, and the origins of gravitational lens research (German Title: Im Rampenlicht der Sterne. Einstein, Mandl und die Ursprünge der Gravitationslinsenforschung)

NASA Astrophysics Data System (ADS)

Renn, Jürgen; Sauer, Tilman

Einstein's paper on gravitational lensing from 1936 was published only as a result of insistent prodding by the Czech amateur scientist Rudi Mandl. We discuss Mandl's role for the publication history of Einstein's paper and point out striking similarities between Mandl's situation in 1936 and Einstein's own position in 1912. At that time, Einstein himself had already considered the idea of gravitational lensing, as had been discovered some years ago through the identification of research notes from that period. Other early discussions of gravitational lensing by Lodge, Chwolson, Tikhov, Zwicky, Russell, and others were either only perceived or only written after Mandl had succeeded to persuade Einstein into publication.

Einstein's cosmology review of 1933: a new perspective on the Einstein-de Sitter model of the cosmos

NASA Astrophysics Data System (ADS)

O'Raifeartaigh, Cormac; O'Keeffe, Michael; Nahm, Werner; Mitton, Simon

2015-09-01

We present a first English translation and analysis of a little-known review of relativistic cosmology written by Albert Einstein in late 1932. The article, which was published in 1933 in a book of Einstein papers translated into French, contains a substantial review of static and dynamic relativistic models of the cosmos, culminating in a discussion of the Einstein-de Sitter model. The article offers a valuable contemporaneous insight into Einstein's cosmology in the early 1930s and confirms that his interest lay in the development of the simplest model of the cosmos that could account for observation. The article also confirms that Einstein did not believe that simplified relativistic models could give an accurate description of the early universe.

Riemann-Hypothesis Millennium-Problem(MP) Physics Proof via CATEGORY-SEMANTICS(C-S)/F=C Aristotle SQUARE-of-OPPOSITION(SoO) DEduction-LOGIC DichotomY

NASA Astrophysics Data System (ADS)

Baez, J.; Lapidaryus, M.; Siegel, Edward Carl-Ludwig

2011-03-01

Riemann-hypothesis physics-proof combines: Siegel-Antonoff-Smith[AMS Joint Mtg.(2002)-Abs.973-03-126] digits on-average statistics HIll[Am. J. Math 123, 3, 887(1996)] logarithm-function's (1,0)-fixed-point base=units=scale-invariance proven Newcomb[Am. J. Math. 4, 39(1881)]-Weyl[Goett. Nachr.(1914); Math. Ann. 7, 313(1916)]-Benford[Proc. Am. Phil. Soc. 78, 4, 51(1938)]-law [Kac, Math. of Stat.-Reasoning(1955); Raimi, Sci. Am. 221, 109(1969)] algebraic-inversion to ONLY Bose-Einstein quantum-statistics(BEQS) with digit d = 0 gapFUL Bose-Einstein Condensation(BEC) insight that digits are quanta are bosons were always digits, via Siegel-Baez category-semantics tabular list-format matrix truth-table analytics in Plato-Aristotle classic "square-of-opposition" : FUZZYICS=CATEGORYICS/Category-Semantics, with Goodkind Bose-Einstein condensation(BEC) ABOVE ground-state with/and Rayleigh(cut-limit of "short-cut method";1870)-Polya(1922)-"Anderson"(1958) localization [Doyle and Snell, Random-Walks and Electrical-Networks, MAA(1981)-p.99-100!!!].

Thermalization of a two-dimensional photonic gas in a `white wall' photon box

NASA Astrophysics Data System (ADS)

Klaers, Jan; Vewinger, Frank; Weitz, Martin

2010-07-01

Bose-Einstein condensation, the macroscopic accumulation of bosonic particles in the energetic ground state below a critical temperature, has been demonstrated in several physical systems. The perhaps best known example of a bosonic gas, blackbody radiation, however exhibits no Bose-Einstein condensation at low temperatures. Instead of collectively occupying the lowest energy mode, the photons disappear in the cavity walls when the temperature is lowered-corresponding to a vanishing chemical potential. Here we report on evidence for a thermalized two-dimensional photon gas with a freely adjustable chemical potential. Our experiment is based on a dye-filled optical microresonator, acting as a `white wall' box for photons. Thermalization is achieved in a photon-number-conserving way by photon scattering off the dye molecules, and the cavity mirrors provide both an effective photon mass and a confining potential-key prerequisites for the Bose-Einstein condensation of photons. As a striking example of the unusual system properties, we demonstrate a yet unobserved light concentration effect into the centre of the confining potential, an effect with prospects for increasing the efficiency of diffuse solar light collection.

Hamiltonian approach to GR - Part 1: covariant theory of classical gravity

NASA Astrophysics Data System (ADS)

Cremaschini, Claudio; Tessarotto, Massimo

2017-05-01

A challenging issue in General Relativity concerns the determination of the manifestly covariant continuum Hamiltonian structure underlying the Einstein field equations and the related formulation of the corresponding covariant Hamilton-Jacobi theory. The task is achieved by adopting a synchronous variational principle requiring distinction between the prescribed deterministic metric tensor \\widehat{g}(r)≡ { \\widehat{g}_{μ ν }(r)} solution of the Einstein field equations which determines the geometry of the background space-time and suitable variational fields x≡ { g,π } obeying an appropriate set of continuum Hamilton equations, referred to here as GR-Hamilton equations. It is shown that a prerequisite for reaching such a goal is that of casting the same equations in evolutionary form by means of a Lagrangian parametrization for a suitably reduced canonical state. As a result, the corresponding Hamilton-Jacobi theory is established in manifestly covariant form. Physical implications of the theory are discussed. These include the investigation of the structural stability of the GR-Hamilton equations with respect to vacuum solutions of the Einstein equations, assuming that wave-like perturbations are governed by the canonical evolution equations.

Collective emission of matter-wave jets from driven Bose-Einstein condensates.

PubMed

Clark, Logan W; Gaj, Anita; Feng, Lei; Chin, Cheng

2017-11-16

Scattering is used to probe matter and its interactions in all areas of physics. In ultracold atomic gases, control over pairwise interactions enables us to investigate scattering in quantum many-body systems. Previous experiments on colliding Bose-Einstein condensates have revealed matter-wave interference, haloes of scattered atoms, four-wave mixing and correlations between counter-propagating pairs. However, a regime with strong stimulation of spontaneous collisions analogous to superradiance has proved elusive. In this regime, the collisions rapidly produce highly correlated states with macroscopic population. Here we find that runaway stimulated collisions in Bose-Einstein condensates with periodically modulated interaction strength cause the collective emission of matter-wave jets that resemble fireworks. Jets appear only above a threshold modulation amplitude and their correlations are invariant even when the number of ejected atoms grows exponentially. Hence, we show that the structures and atom occupancies of the jets stem from the quantum fluctuations of the condensate. Our findings demonstrate the conditions required for runaway stimulated collisions and reveal the quantum nature of matter-wave emission.

Phase collapse and revival of a 1-mode Bose-Einstein condensate induced by an off-resonant optical probe field and superselection rules

NASA Astrophysics Data System (ADS)

Arruda, L. G. E.; Prataviera, G. A.; de Oliveira, M. C.

2018-02-01

Phase collapse and revival for Bose-Einstein condensates are nonlinear phenomena appearing due to atomic collisions. While it has been observed in a general setting involving many modes, for one-mode condensates its occurrence is forbidden by the particle number superselection rule (SSR), which arises because there is no phase reference available. We consider a single mode atomic Bose-Einstein condensate interacting with an off-resonant optical probe field. We show that the condensate phase revival time is dependent on the atom-light interaction, allowing optical control on the atomic collapse and revival dynamics. Incoherent effects over the condensate phase are included by considering a continuous photo-detection over the probe field. We consider conditioned and unconditioned photo-counting events and verify that no extra control upon the condensate is achieved by the probe photo-detection, while further inference of the atomic system statistics is allowed leading to a useful test of the SSR on particle number and its imposition on the kind of physical condensate state.

Einstein, race, and the myth of the cultural icon

NASA Astrophysics Data System (ADS)

Jerome, Fred

2004-12-01

The most remarkable aspect of Einstein's 1946 address at Lincoln University is that it has vanished from Einstein's recorded history. Its disappearance into a historical black hole symbolizes what seems to happen in the creation of a cultural icon. It is but one of many political statements by Einstein to have met such a fate, though his civil rights activism is most glaringly mission. One explanation for this historical amnesia is that those who shape our official memories felt that Einstein's "controversial" friends like Paul Robeson and activities like co-chairing the anti-lynching crusade might tarnish Einstein as an icon. That icon, sanctified by Time magazine when it dubbed Einstein "Person of the Century" at the end of 1999, is a myth, albeit a marvelous one. Yet it is not so much the motive for the omission but the consequence of it that should concern us. Americans and the millions of Einstein fans around the world are left unaware that he was an outspoken, passionate, committed antiracist.

Rediscovering Einstein's legacy: How Einstein anticipates Kuhn and Feyerabend on the nature of science.

PubMed

Oberheim, Eric

2016-06-01

Thomas Kuhn and Paul Feyerabend promote incommensurability as a central component of their conflicting accounts of the nature of science. This paper argues that in so doing, they both develop Albert Einstein's views, albeit in different directions. Einstein describes scientific revolutions as conceptual replacements, not mere revisions, endorsing 'Kant-on-wheels' metaphysics in light of 'world change'. Einstein emphasizes underdetermination of theory by evidence, rational disagreement in theory choice, and the non-neutrality of empirical evidence. Einstein even uses the term 'incommensurable' specifically to apply to challenges posed to comparatively evaluating scientific theories in 1949, more than a decade before Kuhn and Feyerabend. This analysis shows how Einstein anticipates substantial components of Kuhn and Feyerabend's views, and suggests that there are strong reasons to suspect that Kuhn and Feyerabend were directly inspired by Einstein's use of the term 'incommensurable', as well as his more general methodological and philosophical reflections. Copyright © 2015 Elsevier Ltd. All rights reserved.

Einstein-Podolsky-Rosen correlations and Bell correlations in the simplest scenario

NASA Astrophysics Data System (ADS)

Quan, Quan; Zhu, Huangjun; Fan, Heng; Yang, Wen-Li

2017-06-01

Einstein-Podolsky-Rosen (EPR) steering is an intermediate type of quantum nonlocality which sits between entanglement and Bell nonlocality. A set of correlations is Bell nonlocal if it does not admit a local hidden variable (LHV) model, while it is EPR nonlocal if it does not admit a local hidden variable-local hidden state (LHV-LHS) model. It is interesting to know what states can generate EPR-nonlocal correlations in the simplest nontrivial scenario, that is, two projective measurements for each party sharing a two-qubit state. Here we show that a two-qubit state can generate EPR-nonlocal full correlations (excluding marginal statistics) in this scenario if and only if it can generate Bell-nonlocal correlations. If full statistics (including marginal statistics) is taken into account, surprisingly, the same scenario can manifest the simplest one-way steering and the strongest hierarchy between steering and Bell nonlocality. To illustrate these intriguing phenomena in simple setups, several concrete examples are discussed in detail, which facilitates experimental demonstration. In the course of study, we introduce the concept of restricted LHS models and thereby derive a necessary and sufficient semidefinite-programming criterion to determine the steerability of any bipartite state under given measurements. Analytical criteria are further derived in several scenarios of strong theoretical and experimental interest.

Einstein as Evaluator?

ERIC Educational Resources Information Center

Caulley, Darrel N.

1982-01-01

Like any other person, Albert Einstein was an informal evaluator, engaged in placing value on various aspects of his life, work, and the world. Based on Einstein's own statements, this paper speculates about what Einstein would have been like as a connoisseur evaluator, a conceptual evaluator, or a responsive evaluator. (Author/BW)

Stability of the Einstein static universe in Einstein-Cartan theory

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

Atazadeh, K., E-mail: atazadeh@azaruniv.ac.ir

The existence and stability of the Einstein static solution have been built in the Einstein-Cartan gravity. We show that this solution in the presence of perfect fluid with spin density satisfying the Weyssenhoff restriction is cyclically stable around a center equilibrium point. Thus, study of this solution is interesting because it supports non-singular emergent cosmological models in which the early universe oscillates indeterminately about an initial Einstein static solution and is thus past eternal.

Quantum effects of translational motions in solid para-hydrogen and ortho-deuterium: anharmonic extension of the Einstein model.

PubMed

Kühn, O; Manz, J; Schild, A

2010-04-07

An anharmonic extension of the Einstein model is developed in order to describe the effect of translational zero point motion on structural and thermodynamic properties of para-H(2) and ortho-D(2) crystals in the zero temperature limit. Accordingly, the molecules carry out large amplitude translational motions in their matrix cage, which are formed by the frozen environment of all other molecules. These translations lead from the molecular equilibrium positions via the harmonic to the anharmonic domain of the potential energy surface. The resulting translational distributions are roughly isotropic, and they have approximately Gaussian shapes, with rather broad full widths at half-maximum, FWHM(para-H(2)/ortho-D(2)) = 1.36/1.02 Å. The translational zero point energies induce expansions of the crystals, in nearly quantitative agreement with experimental results. Furthermore, they make significant contributions to the sublimation energies and zero pressure bulk moduli. These quantum effects decrease with heavier molecular masses. The corresponding isotope effects for ortho-D(2) compared to para-H(2) are confirmed by application of the model to Ar crystals. The results imply consequences for laser induced reaction dynamics of dopants with their host crystals.

Einstein's Jury: Trial by Telescope

NASA Astrophysics Data System (ADS)

Crelinsten, Jeffrey

2007-03-01

While Einstein's theory of relativity ultimately laid the foundation for modern studies of the universe, it took a long time to be accepted. Between 1905 and 1930, relativity was poorly understood and Einstein worked hard to try to make it more accessible to scientists and scientifically literate laypeople. Its acceptance was largely due to the astronomy community, which undertook precise measurements to test Einstein's astronomical predictions. The well-known 1919 British eclipse expeditions that made Einstein famous did not convince most scientists to accept relativity. The 1920s saw numerous attempts to measure light-bending, as well as solar line displacements and even ether-drift. How astronomers approached the ``Einstein problem'' in these early years before and after the First World War, and how the public reacted to what they reported, helped to shape attitudes we hold today about Einstein and his ideas.

Spatially indirect excitons in coupled quantum wells

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

Lai, Chih-Wei Eddy

2004-03-01

Microscopic quantum phenomena such as interference or phase coherence between different quantum states are rarely manifest in macroscopic systems due to a lack of significant correlation between different states. An exciton system is one candidate for observation of possible quantum collective effects. In the dilute limit, excitons in semiconductors behave as bosons and are expected to undergo Bose-Einstein condensation (BEC) at a temperature several orders of magnitude higher than for atomic BEC because of their light mass. Furthermore, well-developed modern semiconductor technologies offer flexible manipulations of an exciton system. Realization of BEC in solid-state systems can thus provide new opportunitiesmore » for macroscopic quantum coherence research. In semiconductor coupled quantum wells (CQW) under across-well static electric field, excitons exist as separately confined electron-hole pairs. These spatially indirect excitons exhibit a radiative recombination time much longer than their thermal relaxation time a unique feature in direct band gap semiconductor based structures. Their mutual repulsive dipole interaction further stabilizes the exciton system at low temperature and screens in-plane disorder more effectively. All these features make indirect excitons in CQW a promising system to search for quantum collective effects. Properties of indirect excitons in CQW have been analyzed and investigated extensively. The experimental results based on time-integrated or time-resolved spatially-resolved photoluminescence (PL) spectroscopy and imaging are reported in two categories. (i) Generic indirect exciton systems: general properties of indirect excitons such as the dependence of exciton energy and lifetime on electric fields and densities were examined. (ii) Quasi-two-dimensional confined exciton systems: highly statistically degenerate exciton systems containing more than tens of thousands of excitons within areas as small as (10 micrometer) 2 were observed. The spatial and energy distributions of optically active excitons were used as thermodynamic quantities to construct a phase diagram of the exciton system, demonstrating the existence of distinct phases. Optical and electrical properties of the CQW sample were examined thoroughly to provide deeper understanding of the formation mechanisms of these cold exciton systems. These insights offer new strategies for producing cold exciton systems, which may lead to opportunities for the realization of BEC in solid-state systems.« less

Einstein as a Missionary of Science

NASA Astrophysics Data System (ADS)

Renn, Jürgen

2013-10-01

The paper reviews Einstein's engagement as a mediator and popularizer of science. It discusses the formative role of popular scientific literature for the young Einstein, showing that not only his broad scientific outlook but also his internationalist political views were shaped by these readings. Then, on the basis of recent detailed studies, Einstein's travels and their impact on the dissemination of relativity theory are examined. These activities as well as Einstein's own popular writings are interpreted in the context of his understanding of science as part of human culture.

BOOK REVIEW: Once Upon Einstein

NASA Astrophysics Data System (ADS)

Giannetto, E.

2007-07-01

Thibault Damour is a theoretical physicist, and a member of the French Academy of Sciences. This book is the translation, by Eric Novak, of the original French Si Einstein m'etait conté (Le Cherche Midi, 2005). It is neither a book of theoretical physics nor a biography of Einstein. It is not a book of history nor philosophy of science. In Damour's words it was written to encourage the reader to share with Einstein `those times when he understood some part of the hidden order of the universe'. It is a relatively short book, written in a very fluent style, but it deals with all the major problems and achievements of Einstein's works. Starting from special relativity, it continues with general relativity, quantum theories, unified field theory and a brief overview of the actual research related to Einstein's legacy. It is essentially a popular science book with some related exploration in history and philosophy to interpret physical theories. The most important problem discussed by Damour is the nature of time. On this subject, there is a very interesting short paragraph (pp 33--35) dedicated to the reception of the relativity idea by the great writer Marcel Proust and its counterpart within À la Recherche du Temps Perdu. A correct discussion of the implications of a relativistic time should imply the distinction of the different possible interpretations of this concept. Damour seems to conclude that only one interpretation is possible: `time does not exist', flowing of time is an illusion. One has to know that Einstein's ideas on time were related to Spinoza's perspective of a knowledge sub specie aeternitatis. However, other interpretations are possible and are related to the idea of time as an actuality. Damour speaks about the controversy between Einstein and Bergson, but Bergson is considered as a philosopher who did not understand relativity. This philosophical problem of relativistic time is indeed related to a historical problem briefly discussed by Damour (pp 17--21, 48--52 and related endnotes): had Henri Poincaré constructed a special relativistic dynamics before Einstein? There is a long debate on this subject in the literature. Damour's answer is negative and his conclusions seem related to the conservation of a myth of Einstein, that is, the rise of special relativity is considered as a creatio ex nihilo within Einstein's mind and Einstein is considered as the only genius able to conceive the relativity of time. Poincaré's texts are undervalued and misunderstood by Damour's cutting quotations from their context. Damour never quotes La Science et l'Hypothèse (1902): we know it was read by Einstein and here Poincaré first (within chapters already published as separate papers in 1900) stated the relativity of time and of simultaneity. Damour never quotes Poincaré's paper published on 5 June 1905, La dynamique de l'èlectron, which presents the first relativistic dynamics, invariant by Lorentz transformations. Poincaré's (July 1905) introduction of a quadrimensional space-time is considered by Damour only a mathematical artifice (p 51) and Damour never said that Minkowski took this idea from Poincaré! Poincaré's interpretation of relativistic time implies that it is not an illusion but a complex net of different real flows related to different processes. Poincaré and Einstein had different conceptions of Nature at the root of special relativity: respectively an electromagnetic conception (Poincaré) and a semi-mechanist one (Einstein). Thus, the (philosophical) meaning of relativity can be very different from the one presented by Damour. Furthermore, Damour accepts Kantian philosophy as a key to understanding relativity and quantum theories. This perspective seems to me very anachronistic and based on a misunderstanding: an interpretation of 20th century physical theories (relativity and quantum physics) is given within the framework of an 18th century philosophical perspective, created to give a foundation to Newton's theory. Relativity and quantum physics imply a breakdown of Kantian philosophy (see, for instance, G Bachelard's La Philosophie du Non). Relativity of space and time was considered possible only by overcoming the epistemological obstacle of Kantian idealistic foundation of Euclidean geometry and of Newton's absolute space and time. Relativity and quantum theories turn up not only the hierarchy between mathematics and physics, but also between epistemology (and logic) and physics: quantum physics implies not only a new conception of an indeterminate and unpredictable Nature, but a quantum logic too, that is, it implies a change in our way of thinking and knowing. When will the revolutionary impact of 20th century physics be reduced (by physicists themselves) to an already given philosophical framework?

Self-consistent phonon theory of the crystallization and elasticity of attractive hard spheres.

PubMed

Shin, Homin; Schweizer, Kenneth S

2013-02-28

We propose an Einstein-solid, self-consistent phonon theory for the crystal phase of hard spheres that interact via short-range attractions. The approach is first tested against the known behavior of hard spheres, and then applied to homogeneous particles that interact via short-range square well attractions and the Baxter adhesive hard sphere model. Given the crystal symmetry, packing fraction, and strength and range of attractive interactions, an effective harmonic potential experienced by a particle confined to its Wigner-Seitz cell and corresponding mean square vibrational amplitude are self-consistently calculated. The crystal free energy is then computed and, using separate information about the fluid phase free energy, phase diagrams constructed, including a first-order solid-solid phase transition and its associated critical point. The simple theory qualitatively captures all the many distinctive features of the phase diagram (critical and triple point, crystal-fluid re-entrancy, low-density coexistence curve) as a function of attraction range, and overall is in good semi-quantitative agreement with simulation. Knowledge of the particle localization length allows the crystal shear modulus to be estimated based on elementary ideas. Excellent predictions are obtained for the hard sphere crystal. Expanded and condensed face-centered cubic crystals are found to have qualitatively different elastic responses to varying attraction strength or temperature. As temperature increases, the expanded entropic solid stiffens, while the energy-controlled, fully-bonded dense solid softens.

Dependence of Exciton Diffusion Length and Diffusion Coefficient on Photophysical Parameters in Bulk Heterojunction Organic Solar Cells

NASA Astrophysics Data System (ADS)

Yeboah, Douglas; Singh, Jai

2017-11-01

Recently, the dependence of exciton diffusion length (LD ) on some photophysical parameters of organic solids has been experimentally demonstrated, however no systematic theoretical analysis of this phenomenon has been carried out. We have conducted a theoretical study by using the Förster resonance energy transfer and Dexter carrier transfer mechanisms together with the Einstein-Smoluchowski diffusion equation to derive analytical models for the diffusion lengths (LD ) and diffusion coefficients (D) of singlet (S) and triplet (T) excitons in organic solids as functions of spectral overlap integral (J) , photoluminescence (PL) quantum yield (φD ) , dipole moment (μT ) and refractive index (n) of the photoactive material. The exciton diffusion lengths and diffusion coefficients in some selected organic solids were calculated, and we found that the singlet exciton diffusion length (LDS ) increases with φD and J, and decreases with n. Also, the triplet exciton diffusion length (LDT ) increases with φD and decreases with μT . These may be achieved through doping the organic solids into broad optical energy gap host materials as observed in previous experiments. The calculated exciton diffusion lengths are compared with experimental values and a reasonably good agreement is found between them. The results presented are expected to provide insight relevant to the synthesis of new organic solids for fabrication of bulk heterojunction organic solar cells characterized by better power conversion efficiency.

Singularity-free solutions for anisotropic charged fluids with Chaplygin equation of state

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

Rahaman, Farook; Ray, Saibal; Jafry, Abdul Kayum

2010-11-15

We extend the Krori-Barua analysis of the static, spherically symmetric, Einstein-Maxwell field equations and consider charged fluid sources with anisotropic stresses. The inclusion of a new variable (tangential pressure) allows the use of a nonlinear, Chaplygin-type equation of state with coefficients fixed by the matching conditions at the boundary of the source. Some physical features are briefly discussed.

Astrophysical observations: lensing and eclipsing Einstein's theories.

PubMed

Bennett, Charles L

2005-02-11

Albert Einstein postulated the equivalence of energy and mass, developed the theory of special relativity, explained the photoelectric effect, and described Brownian motion in five papers, all published in 1905, 100 years ago. With these papers, Einstein provided the framework for understanding modern astrophysical phenomena. Conversely, astrophysical observations provide one of the most effective means for testing Einstein's theories. Here, I review astrophysical advances precipitated by Einstein's insights, including gravitational redshifts, gravitational lensing, gravitational waves, the Lense-Thirring effect, and modern cosmology. A complete understanding of cosmology, from the earliest moments to the ultimate fate of the universe, will require developments in physics beyond Einstein, to a unified theory of gravity and quantum physics.

Astronomers' Race to Test Relativity, 1911-1930

NASA Astrophysics Data System (ADS)

Crelinsten, Jeffrey

2006-11-01

Einstein's theory of relativity changed our notions of space and time and has dramatically altered the way we look at the universe and our place in it. Yet to this day a working knowledge of the theory is beyond most people. In today's popular culture, Einstein is a remote, loveable genius and his theory is incomprehensible. While Einstein's theory ultimately laid the foundation for modern studies of the universe, it took a long time to be accepted. Between 1905 and 1930, relativity was poorly understood and Einstein worked hard to try to make it more accessible to scientists and scientifically literate laypeople. Its acceptance was largely due to the astronomy community, which undertook precise measurements to test Einstein's astronomical predictions. How astronomers approached the ``Einstein problem'' in these early years and how the public reacted to what they reported helped to shape attitudes we hold today about Einstein and his ideas.

Is Electromagnetic Gravity Control Possible?

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

Vargas, Jose G.; Torr, Douglas G.

2004-02-04

We study the interplay of Einstein's Gravitation (GR) and Maxwell's Electromagnetism, where the distribution of energy-momentum is not presently known (The Feynman Lectures, Vol 2, Chapter 27, section 4). As Feynman himself stated, one might in principle use Einstein's equations of GR to find such a distribution. GR (born in 1915) presently uses the Levi-Civita connection, LCC (the LCC was born two years after GR as a new concept, and not just as the pre-existing Christoffel symbols that represent it). Around 1927, Einstein proposed for physics an alternative to the LCC that constitutes a far more sensible and powerful affinemore » enrichment of metric Riemannian geometry. It is called teleparallelism (TP). Its Finslerian version (i.e. in the space-time-velocity arena) permits an unequivocal identification of the EM field as a geometric quantity. This in turn permits one to identify a completely geometric set of Einstein equations from curvature equations. From their right hand side, one may obtain the actual distribution of EM energy-momentum. It is consistent with Maxwell's equations, since these also are implied by the equations of structure of TP. We find that the so-far-unknown terms in this distribution amount to a total differential and do not, therefore, alter the value of the total EM energy-momentum. And yet these extra terms are at macroscopic distances enormously larger than the standard quadratic terms. This allows for the generation of measurable gravitational fields by EM fields. We thus answer affirmatively the question of the title.« less

Series expansion of the modified Einstein Procedure

Treesearch

Seema Chandrakant Shah-Fairbank

2009-01-01

This study examines calculating total sediment discharge based on the Modified Einstein Procedure (MEP). A new procedure based on the Series Expansion of the Modified Einstein Procedure (SEMEP) has been developed. This procedure contains four main modifications to MEP. First, SEMEP solves the Einstein integrals quickly and accurately based on a series expansion. Next,...

Einstein for Schools and the General Public

ERIC Educational Resources Information Center

Johansson, K. E.; Kozma, C; Nilsson, Ch

2006-01-01

In April 2005 the World Year of Physics (Einstein Year in the UK and Ireland) was celebrated with an Einstein week in Stockholm House of Science. Seven experiments illustrated Einstein's remarkable work in 1905 on Brownian motion, the photoelectric effect and special relativity. Thirteen school classes with 260 pupils, 30 teachers and 25 members…

Conceptual Development of Einstein's Mass-Energy Relationship

ERIC Educational Resources Information Center

Wong, Chee Leong; Yap, Kueh Chin

2005-01-01

Einstein's special theory of relativity was published in 1905. It stands as one of the greatest intellectual achievements in the history of human thought. Einstein described the equivalence of mass and energy as "the most important upshot of the special theory of relativity" (Einstein, 1919). In this paper, we will discuss the evolution of the…

EPR before EPR: A 1930 Einstein-Bohr thought Experiment Revisited

ERIC Educational Resources Information Center

Nikolic, Hrvoje

2012-01-01

In 1930, Einstein argued against the consistency of the time-energy uncertainty relation by discussing a thought experiment involving a measurement of the mass of the box which emitted a photon. Bohr seemingly prevailed over Einstein by arguing that Einstein's own general theory of relativity saves the consistency of quantum mechanics. We revisit…

The Coupling of Gravity to Spin and Electromagnetism

NASA Astrophysics Data System (ADS)

Finster, Felix; Smoller, Joel; Yau, Shing-Tung

The coupled Einstein-Dirac-Maxwell equations are considered for a static, spherically symmetric system of two fermions in a singlet spinor state. Stable soliton-like solutions are shown to exist, and we discuss the regularizing effect of gravity from a Feynman diagram point of view.

Optimal quantum control of Bose-Einstein condensates in magnetic microtraps: Comparison of gradient-ascent-pulse-engineering and Krotov optimization schemes

NASA Astrophysics Data System (ADS)

Jäger, Georg; Reich, Daniel M.; Goerz, Michael H.; Koch, Christiane P.; Hohenester, Ulrich

2014-09-01

We study optimal quantum control of the dynamics of trapped Bose-Einstein condensates: The targets are to split a condensate, residing initially in a single well, into a double well, without inducing excitation, and to excite a condensate from the ground state to the first-excited state of a single well. The condensate is described in the mean-field approximation of the Gross-Pitaevskii equation. We compare two optimization approaches in terms of their performance and ease of use; namely, gradient-ascent pulse engineering (GRAPE) and Krotov's method. Both approaches are derived from the variational principle but differ in the way the control is updated, additional costs are accounted for, and second-order-derivative information can be included. We find that GRAPE produces smoother control fields and works in a black-box manner, whereas Krotov with a suitably chosen step-size parameter converges faster but can produce sharp features in the control fields.

Many-body physics in two-component Bose–Einstein condensates in a cavity: fragmented superradiance and polarization

NASA Astrophysics Data System (ADS)

Lode, Axel U. J.; Diorico, Fritz S.; Wu, RuGway; Molignini, Paolo; Papariello, Luca; Lin, Rui; Lévêque, Camille; Exl, Lukas; Tsatsos, Marios C.; Chitra, R.; Mauser, Norbert J.

2018-05-01

We consider laser-pumped one-dimensional two-component bosons in a parabolic trap embedded in a high-finesse optical cavity. Above a threshold pump power, the photons that populate the cavity modify the effective atom trap and mediate a coupling between the two components of the Bose–Einstein condensate. We calculate the ground state of the laser-pumped system and find different stages of self-organization depending on the power of the laser. The modified potential and the laser-mediated coupling between the atomic components give rise to rich many-body physics: an increase of the pump power triggers a self-organization of the atoms while an even larger pump power causes correlations between the self-organized atoms—the BEC becomes fragmented and the reduced density matrix acquires multiple macroscopic eigenvalues. In this fragmented superradiant state, the atoms can no longer be described as two-level systems and the mapping of the system to the Dicke model breaks down.

Phase Diagram for Magnon Condensate in Yttrium Iron Garnet Film

PubMed Central

Li, Fuxiang; Saslow, Wayne M.; Pokrovsky, Valery L.

2013-01-01

Recently, magnons, which are quasiparticles describing the collective motion of spins, were found to undergo Bose-Einstein condensation (BEC) at room temperature in films of Yttrium Iron Garnet (YIG). Unlike other quasiparticle BEC systems, this system has a spectrum with two degenerate minima, which makes it possible for the system to have two condensates in momentum space. Recent Brillouin Light Scattering studies for a microwave-pumped YIG film of thickness d = 5 μm and field H = 1 kOe find a low-contrast interference pattern at the characteristic wavevector Q of the magnon energy minimum. In this report, we show that this modulation pattern can be quantitatively explained as due to unequal but coherent Bose-Einstein condensation of magnons into the two energy minima. Our theory predicts a transition from a high-contrast symmetric state to a low-contrast non-symmetric state on varying the d and H, and a new type of collective oscillation. PMID:23455849

Demonstration of Multisetting One-Way Einstein-Podolsky-Rosen Steering in Two-Qubit Systems

NASA Astrophysics Data System (ADS)

Xiao, Ya; Ye, Xiang-Jun; Sun, Kai; Xu, Jin-Shi; Li, Chuan-Feng; Guo, Guang-Can

2017-04-01

Einstein-Podolsky-Rosen (EPR) steering describes the ability of one party to remotely affect another's state through local measurements. One of the most distinguishable properties of EPR steering is its asymmetric aspect. Steering can work in one direction but fail in the opposite direction. This type of one-way steering, which is different from the symmetry concepts of entanglement and Bell nonlocality, has garnered much interest. However, an experimental demonstration of genuine one-way EPR steering in the simplest scenario, i.e., one that employs two-qubit systems, is still lacking. In this Letter, we experimentally demonstrate one-way EPR steering with multimeasurement settings for a class of two-qubit states, which are still one-way steerable even with infinite settings. The steerability is quantified by the steering radius, which represents a necessary and sufficient steering criterion. The demonstrated one-way steering in the simplest bipartite quantum system is of fundamental interest and may provide potential applications in one-way quantum information tasks.

Coherent inflationary dynamics for Bose-Einstein condensates crossing a quantum critical point

NASA Astrophysics Data System (ADS)

Feng, Lei; Clark, Logan W.; Gaj, Anita; Chin, Cheng

2018-03-01

Quantum phase transitions, transitions between many-body ground states, are of extensive interest in research ranging from condensed-matter physics to cosmology1-4. Key features of the phase transitions include a stage with rapidly growing new order, called inflation in cosmology5, followed by the formation of topological defects6-8. How inflation is initiated and evolves into topological defects remains a hot topic of debate. Ultracold atomic gas offers a pristine and tunable platform to investigate quantum critical dynamics9-21. We report the observation of coherent inflationary dynamics across a quantum critical point in driven Bose-Einstein condensates. The inflation manifests in the exponential growth of density waves and populations in well-resolved momentum states. After the inflation stage, extended coherent dynamics is evident in both real and momentum space. We present an intuitive description of the quantum critical dynamics in our system and demonstrate the essential role of phase fluctuations in the formation of topological defects.

Bulk entanglement gravity without a boundary: Towards finding Einstein's equation in Hilbert space

NASA Astrophysics Data System (ADS)

Cao, ChunJun; Carroll, Sean M.

2018-04-01

We consider the emergence from quantum entanglement of spacetime geometry in a bulk region. For certain classes of quantum states in an appropriately factorized Hilbert space, a spatial geometry can be defined by associating areas along codimension-one surfaces with the entanglement entropy between either side. We show how radon transforms can be used to convert these data into a spatial metric. Under a particular set of assumptions, the time evolution of such a state traces out a four-dimensional spacetime geometry, and we argue using a modified version of Jacobson's "entanglement equilibrium" that the geometry should obey Einstein's equation in the weak-field limit. We also discuss how entanglement equilibrium is related to a generalization of the Ryu-Takayanagi formula in more general settings, and how quantum error correction can help specify the emergence map between the full quantum-gravity Hilbert space and the semiclassical limit of quantum fields propagating on a classical spacetime.

The fate of a gray soliton in a quenched Bose-Einstein condensate

NASA Astrophysics Data System (ADS)

Gamayun, Oleksandr; Bezvershenko, Yulia; Cheianov, Vadim

2015-03-01

We investigate the destiny of a gray soliton in a repulsive one-dimensional Bose-Einstein condensate undergoing a sudden quench of the non-linearity parameter. The outcome of the quench is found to depend dramatically on the ratio η of the final and initial values of the speed of sound. For integer η the soliton splits into exactly 2 η - 1 solitons. For non-integer η the soliton decays into multiple solitons and Bogoliubov modes. The case of integer η is analyzed in detail. The parameters of solitons in the out-state are found explicitly. Our approach exploits the inverse scattering method and can be easily used for the similar quenches in any classical integrable system.

Multipion correlations induced by isospin conservation of coherent emission

DOE PAGES

Gangadharan, Dhevan

2016-09-15

Recent measurements have revealed a significant suppression of multipion Bose–Einstein correlations in heavy-ion collisions at the LHC. The suppression may be explained by postulating coherent pion emission. Typically, the suppression of Bose–Einstein correlations due to coherence is taken into account with the coherent state formalism in quantum optics. However, since charged pion correlations are most often measured, the additional constraint of isospin conservation, which is absent in quantum optics, needs to be taken into account. As a consequence, correlations emerge between pions of opposite charge. A calculation of the correlations induced by isospin conservation of coherent emission is made formore » two, three- and four-pion correlation functions and compared to the data from the LHC.« less

Half Century of Black-Hole Theory: From Physicists' Purgatory to Mathematicians' Paradise

NASA Astrophysics Data System (ADS)

Carter, Brandon

2006-06-01

Although implicit in the discovery of the Schwarzschild solution 40 years earlier, the issues raised by the theory of what are now known as black holes were so unsettling to physicists of Einstein's generation that the subject remained in a state of semiclandestine gestation until his demise. That turning point — just half a century after Einstein's original foundation of relativity theory, and just half a century ago today — can be considered to mark the birth of black hole theory as a subject of systematic development by physicists of a new and less inhibited generation, whose enthusastic investigations have revealed structures of unforeseen mathematical beauty, even though questions about the physical significance of the concomitant singularities remain controversial.

Ionic Impurity in a Bose-Einstein Condensate at Submicrokelvin Temperatures

NASA Astrophysics Data System (ADS)

Kleinbach, K. S.; Engel, F.; Dieterle, T.; Löw, R.; Pfau, T.; Meinert, F.

2018-05-01

Rydberg atoms immersed in a Bose-Einstein condensate interact with the quantum gas via electron-atom and ion-atom interaction. To suppress the typically dominant electron-neutral interaction, Rydberg states with a principal quantum number up to n =190 are excited from a dense and tightly trapped micron-sized condensate. This allows us to explore a regime where the Rydberg orbit exceeds the size of the atomic sample by far. In this case, a detailed line shape analysis of the Rydberg excitation spectrum provides clear evidence for ion-atom interaction at temperatures well below a microkelvin. Our results may open up ways to enter the quantum regime of ion-atom scattering for the exploration of charged quantum impurities and associated polaron physics.

Dark matter admixed strange quark stars in the Starobinsky model

NASA Astrophysics Data System (ADS)

Lopes, Ilídio; Panotopoulos, Grigoris

2018-01-01

We compute the mass-to-radius profiles for dark matter admixed strange quark stars in the Starobinsky model of modified gravity. For quark matter, we assume the MIT bag model, while self-interacting dark matter inside the star is modeled as a Bose-Einstein condensate with a polytropic equation of state. We numerically integrate the structure equations in the Einstein frame, adopting the two-fluid formalism, and we treat the curvature correction term nonperturbatively. The effects on the properties of the stars of the amount of dark matter as well as the higher curvature term are investigated. We find that strange quark stars (in agreement with current observational constraints) with the highest masses are equally affected by dark matter and modified gravity.

Spatially distributed multipartite entanglement enables EPR steering of atomic clouds

NASA Astrophysics Data System (ADS)

Kunkel, Philipp; Prüfer, Maximilian; Strobel, Helmut; Linnemann, Daniel; Frölian, Anika; Gasenzer, Thomas; Gärttner, Martin; Oberthaler, Markus K.

2018-04-01

A key resource for distributed quantum-enhanced protocols is entanglement between spatially separated modes. However, the robust generation and detection of entanglement between spatially separated regions of an ultracold atomic system remain a challenge. We used spin mixing in a tightly confined Bose-Einstein condensate to generate an entangled state of indistinguishable particles in a single spatial mode. We show experimentally that this entanglement can be spatially distributed by self-similar expansion of the atomic cloud. We used spatially resolved spin read-out to reveal a particularly strong form of quantum correlations known as Einstein-Podolsky-Rosen (EPR) steering between distinct parts of the expanded cloud. Based on the strength of EPR steering, we constructed a witness, which confirmed genuine 5-partite entanglement.

Efficient Scheme for Perfect Collective Einstein-Podolsky-Rosen Steering

PubMed Central

Wang, M.; Gong, Q. H.; Ficek, Z.; He, Q. Y.

2015-01-01

A practical scheme for the demonstration of perfect one-sided device-independent quantum secret sharing is proposed. The scheme involves a three-mode optomechanical system in which a pair of independent cavity modes is driven by short laser pulses and interact with a movable mirror. We demonstrate that by tuning the laser frequency to the blue (anti-Stokes) sideband of the average frequency of the cavity modes, the modes become mutually coherent and then may collectively steer the mirror mode to a perfect Einstein-Podolsky-Rosen state. The scheme is shown to be experimentally feasible, it is robust against the frequency difference between the modes, mechanical thermal noise and damping, and coupling strengths of the cavity modes to the mirror. PMID:26212901

METHODOLOGICAL NOTES: The Einstein-Podolsky-Rosen paradox for energy-time variables

NASA Astrophysics Data System (ADS)

Klyshko, D. N.

1989-06-01

A new variant of the Einstein-Podolsky-Rosen experiment is discussed which illustrates the complementarity principle and the indeterminancy relations for the energy and the time of creation of photons emitted as correlated pairs in the decay of a metastable state of an atom or in parametric scattering of light. It is shown that it is not possible a priori to ascribe to such photons a definite temporal structure; it acquires an operational meaning only after one of the photons of the pair is recorded by a detector with a definite frequency characteristic. A simple interpretation of the effect is possible by means of an advanced wave emitted by one of the detectors at the instant of the photon being recorded.

Macroscopic quantum tunneling escape of Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Zhao, Xinxin; Alcala, Diego A.; McLain, Marie A.; Maeda, Kenji; Potnis, Shreyas; Ramos, Ramon; Steinberg, Aephraim M.; Carr, Lincoln D.

2017-12-01

Recent experiments on macroscopic quantum tunneling reveal a nonexponential decay of the number of atoms trapped in a quasibound state behind a potential barrier. Through both experiment and theory, we demonstrate this nonexponential decay results from interactions between atoms. Quantum tunneling of tens of thousands of 87Rb atoms in a Bose-Einstein condensate is modeled by a modified Jeffreys-Wentzel-Kramers-Brillouin model, taking into account the effective time-dependent barrier induced by the mean field. Three-dimensional Gross-Pitaevskii simulations corroborate a mean-field result when compared with experiments. However, with one-dimensional modeling using time-evolving block decimation, we present an effective renormalized mean-field theory that suggests many-body dynamics for which a bare mean-field theory may not apply.

Fast production of Bose-Einstein condensates of metastable helium

NASA Astrophysics Data System (ADS)

Bouton, Q.; Chang, R.; Hoendervanger, A. L.; Nogrette, F.; Aspect, A.; Westbrook, C. I.; Clément, D.

2015-06-01

We report on the Bose-Einstein condensation of metastable 4He atoms using a hybrid approach, consisting of a magnetic quadrupole and an optical dipole trap. In our setup we cross the phase transition with 2 ×106 atoms, and we obtain pure condensates of 5 ×105 atoms in the optical trap. This approach to cooling 4He provides enhanced cycle stability, large optical access to the atoms and results in the production of a condensate every 6 s—a factor 2 faster than the state of the art. This speed-up will significantly reduce the data acquisition time needed for the measurement of many particle correlations, made possible by the ability of metastable helium atoms to be detected individually.

Dynamic wormhole solutions in Einstein-Cartan gravity

NASA Astrophysics Data System (ADS)

Mehdizadeh, Mohammad Reza; Ziaie, Amir Hadi

2017-12-01

In the present work, we investigate evolving wormhole configurations described by a constant redshift function in Einstein-Cartan theory. The matter content consists of a Weyssenhoff fluid along with an anisotropic matter which together generalize the anisotropic energy momentum tensor in general relativity in order to include the effects of intrinsic angular momentum (spin) of particles. Using a generalized Friedmann-Robertson-Walker spacetime, we derive analytical evolving wormhole geometries by assuming a particular equation of state for energy density and pressure profiles. We introduce exact asymptotically flat and anti-de Sitter spacetimes that admit traversable wormholes and respect energy conditions throughout the spacetime. The rate of expansion of these evolving wormholes is determined only by the Friedmann equation in the presence of spin effects.

Regular and Chaotic Spatial Distribution of Bose-Einstein Condensed Atoms in a Ratchet Potential

NASA Astrophysics Data System (ADS)

Li, Fei; Xu, Lan; Li, Wenwu

2018-02-01

We study the regular and chaotic spatial distribution of Bose-Einstein condensed atoms with a space-dependent nonlinear interaction in a ratchet potential. There exists in the system a space-dependent atomic current that can be tuned via Feshbach resonance technique. In the presence of the space-dependent atomic current and a weak ratchet potential, the Smale-horseshoe chaos is studied and the Melnikov chaotic criterion is obtained. Numerical simulations show that the ratio between the intensities of optical potentials forming the ratchet potential, the wave vector of the laser producing the ratchet potential or the wave vector of the modulating laser can be chosen as the controlling parameters to result in or avoid chaotic spatial distributional states.

Remote preparation of a qudit using maximally entangled states of qubits

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

Yu Changshui; Song Heshan; Wang Yahong

2006-02-15

Known quantum pure states of a qudit can be remotely prepared onto a group of particles of qubits exactly or probabilistically with the aid of two-level Einstein-Podolsky-Rosen states. We present a protocol for such kind of remote state preparation. We are mainly focused on the remote preparation of the ensembles of equatorial states and those of states in real Hilbert space. In particular, a kind of states of qudits in real Hilbert space have been shown to be remotely prepared in faith without the limitation of the input space dimension.

Posing Einstein's Question: Questioning Einstein's Pose.

ERIC Educational Resources Information Center

Topper, David; Vincent, Dwight E.

2000-01-01

Discusses the events surrounding a famous picture of Albert Einstein in which he poses near a blackboard containing a tensor form of his 10 field equations for pure gravity with a question mark after it. Speculates as to the content of Einstein's lecture and the questions he might have had about the equation. (Contains over 30 references.) (WRM)

Hidden symmetries on Kerr-NUT-(A)dS metrics of Einstein-Sasaki type

NASA Astrophysics Data System (ADS)

Visinescu, Mihai

2013-01-01

The hidden symmetries of higher dimensional Euclideanised Kerr-NUT-(A)dS metrics are investigated. In certain scaling limits these metrics are related to the Einstein-Sasaki ones. The complete set of Killing-Yano tensors of the Einstein-Sasaki spaces are presented. For this purpose the Killing forms of the Calabi-Yau cone over the Einstein-Sasaki manifold are constructed. Two new Killing forms on Einstein-Sasaki manifolds are identified associated with the complex volume form of the cone manifolds. As a concrete example we present the complete set of Killing-Yano tensors on the five-dimensional Einstein-Sasaki Y(p, q) spaces. The corresponding hidden symmetries are not anomalous and the geodesic equations are superintegrable.

A review of the contributions of Albert Einstein to earth sciences--in commemoration of the World Year of Physics.

PubMed

Martínez-Frías, Jesús; Hochberg, David; Rull, Fernando

2006-02-01

The World Year of Physics (2005) is an international celebration to commemorate the 100th anniversary of Einstein's "Annus Mirabilis." The United Nations has officially declared 2005 as the International Year of Physics. However, the impact of Einstein's ideas was not restricted to physics. Among numerous other disciplines, Einstein also made significant and specific contributions to Earth Sciences. His geosciences-related letters, comments, and scientific articles are dispersed, not easily accessible, and are poorly known. The present review attempts to integrate them as a tribute to Einstein in commemoration of this centenary. These contributions can be classified into three basic areas: geodynamics, geological (planetary) catastrophism, and fluvial geomorphology. Regarding geodynamics, Einstein essentially supported Hapgood's very controversial theory called Earth Crust Displacement. With respect to geological (planetary) catastrophism, it is shown how the ideas of Einstein about Velikovsky's proposals evolved from 1946 to 1955. Finally, in relation to fluvial geodynamics, the review incorporates the elegant work in which Einstein explains the formation of meandering rivers. A general analysis of his contributions is also carried out from today's perspective. Given the interdisciplinarity and implications of Einstein's achievements to multiple fields of knowledge, we propose that the year 2005 serve, rather than to confine his universal figure within a specific scientific area, to broaden it for a better appreciation of this brilliant scientist in all of his dimensions.

[Photoeffects, Einstein's light quanta and the history of their acceptance].

PubMed

Wiederkehr, Karl Heinrich

2006-01-01

It is generally supposed, that the discovery of the efficacy-quantum by Planck was the impetus to Einstein's hypothesis of lightquanta. With its help Einstein could explain the external light-electrical effect. But even years before Einstein had worked at the photoeffect and already made experiments on it. For that reason the article gives a short survey about the history of the lightelectric effects. Lenard's basical work about the release of the photoelectrons is dealt with in detail, without which Einstein would scarcely have found his lightquanta. Furthermore it is shown how difficult it was for the physicists to give up--at least partially--the traditional view of the undulation-nature of light, and how they searched to explain the great energies of the photoelectrons. On the other side it is set forth how Einstein's formula of lightquanta was gradually confirmed. The tragical development of Einstein's personal relations with Johannes Stark and Philipp Lenard are briefly described. Stark was one of the few who supported Einstein's ideas at the beginning. Only with the Compton-effect, which could only be quantitatively interpreted by means of lightquanta and the special theory of relativity 1923, the way was free for the general acceptance of the lightquanta. Einstein did not agree to the obtained dualism of undulation and corpuscle; he had a different solution in mind about the fusion of the two forms of appearance of light.

Einstein 1905-1955: His Approach to Physics

NASA Astrophysics Data System (ADS)

Damour, Thibault

We review Einstein's epistemological conceptions, and indicate their philosophical roots. The particular importance of the ideas of Hume, Kant, Mach, and Poincaré is highlighted. The specific characteristics of Einstein's approach to physics are underlined. Lastly, we consider the practical application of Einstein's methodological principles to the two theories of relativity, and to quantum theory. We emphasize a Kantian approach to quantum theory.

Einstein and Planck

NASA Astrophysics Data System (ADS)

Heilbron, John

2005-03-01

As an editor of the Annalen der Physik, Max Planck published Einstein's early papers on thermodynamics and on special relativity, which Planck probably was the first major physicist to appreciate. They respected one another not only as physicists but also, for their inspired creation of world pictures, as artists. Planck helped to establish Einstein in a sinecure at the center of German physics, Berlin. Despite their differences in scientific style, social life, politics, and religion, they became fast friends. Their mutual admiration survived World War I, during which Einstein advocated pacifism and Planck signed the infamous Manifesto of the 93 Intellectuals supporting the German invasion of Belgium. It also survived the Weimar Republic, which Einstein favored and Planck disliked. Physics drew them together, as both opposed the Copenhagen Interpretation; so did common decency, as Planck helped to protect Einstein from anti-semitic attacks. Their friendship did not survive the Nazis. As a standing secretary of the Berlin Academy, Planck had to advise Einstein to resign from it before his colleagues, outraged at his criticism of the new Germany from the safety of California, expelled him. Einstein never forgave his old friend and former fellow artist for not protesting publicly against his expulsion and denigration, and other enormities of National Socialism. .

Franz Selety (1893-1933?). His cosmological investigations and the correspondence with Einstein (German Title: Franz Selety (1893-1933?). Seine kosmologischen Arbeiten und der Briefwechsel mit Einstein)

NASA Astrophysics Data System (ADS)

Jung, Tobias

In 1922, Franz Selety, university-bred philosopher and self-educated physicist and cosmologist, developed a molecular hierarchical, spatially infinite, Newtonian cosmological model. His considerations were based on his earlier philosophical work published in 1914 as well as on the early correspondence with Einstein in 1917. Historically, the roots of hierarchical models can be seen in 18th century investigations by Thomas Wright of Durham, Immanuel Kant and Johann Heinrich Lambert. Those investigations were taken up by Edmund Fournier d'Albe and Carl Charlier at the beginning of the 20th century. Selety's cosmological model was criticized by Einstein mainly due to its spatial infiniteness which in Einstein's opinion seemed to contradict Mach's principle. This criticism sheds light on Einstein's conviction that with his first cosmological model, namely the static, spatially infinite, though unbounded Einstein Universe of 1917, the appropriate cosmological theory already had been established.

Castles in the Air: The Einstein-De Sitter Debate, 1916-1918

NASA Astrophysics Data System (ADS)

Midwinter, Charles; Janssen, Michel

2011-03-01

The Einstein De Sitter debate marked the birth of modern cosmology and the infamous cosmological constant. For Einstein, the controversy was essentially a philosophical one. Einstein's insistence on a static Universe and Mach's Principle guided him in the construction of his own cosmological model, and compelled him to criticize De Sitter's. For De Sitter, the debate began as idle conjecture. Before long, however, he began to wonder if the "spacious castles" he and Einstein had constructed might actually represent physical reality. We plan to write a volume that reproduces the documents relevant to the debate. Our commentary will retrace and explain the arguments of the historical players, complete with calculations. For the first time readers will be able to follow the arguments of Einstein and De Sitter in a detailed exploration of the first two relativistic cosmological models. Readers will see how Einstein's flawed criticisms of De Sitter were supported by Herman Weyl, and finally how Felix Klein settled the whole matter with a coordinate transformation.

Book Review: Book review

NASA Astrophysics Data System (ADS)

Wegener, Daan

Writing a biography of a complex personality and mastermind like Albert Einstein is a daunting task for any historian of science. Yet the sheer temptation of writing his biography has apparently helped to overcome scholarly scruples, as biographies of Einstein have appeared quite regularly on the market. One of them is Einstein: his Life and Universe by journalist Walter Isaacson. It is a best-seller, which is one of the reasons the book deserves a critical evaluation. Isaacson is a man of considerable repute: he has been the chairman of CNN and managing editor of Time magazine. Isaacson's Einstein is written in a style that is accessible to a wide audience. Scholars who are already familiar with Einstein's physics may still enjoy the parts of the book that deal with the relation between Einstein and the press. Indeed, the breadth of its scope is the book's major merit, as it connects the personal, scientific, public and political dimensions of Einstein's life. In this review, I discuss Isaacson's treatment of these dimensions one-by-one.

Testing cosmology from fundamental considerations: Is the Friedmann universe intrinsically flat

NASA Astrophysics Data System (ADS)

Mitra, Abhas

2014-02-01

Recently Melia and Shevchuk (Mon Not R Astron Soc 419:2579,2012) (MS) have proposed the so-called cosmology where the "Gravitational Horizon" of the universe is equal to the distance travelled by light since "Big Bang". Here we would like to see whether the basic claim is correct or not because MS have not given any cogent derivation for the same. Essentially we will compare the twin expressions for the Einstein energy momentum complex (EMC) of the Friedmann universe obtained by using an appropriate superpotential and also by a direct method. To enable a meaningful comparison of the twin expressions, both are computed by using the same quasi-Cartesian coordinates. We however do not claim that Einstein EMC is superior to many other routes of defining EM of a self-gravitating system. In fact, for static isolated spherical syatems, the idea of a coordinate independent field energy of Lynden-Bell and Katz (Mon Not R Astron Soc 213:21, 1985) might be quite physically significant. Yet, here, we use Einstein EMC because (i) our system is non-static and not isolated one (ii) our primary aim is not find any absolute value of EM, and, finally, (iii) only Einstein pseudo-tensor offers equivalent twin expressions for EM which one can be equated irrespective of any physical significance. Following such comparison of equivalent twin expressions of Einstein energy, we find an exact proof as to why Friedmann universe must be spatially flat even though, mathematically one can conceive of curved spaces in any dimension. Additionally, it follows that, apparently, the scale factor as insisted by proposition. Nonetheless, because of close similarity of this form, , with the (vacuum) Milne metric, and also because of implied unphysical equation of state, cosmology is unlikely to represent the physical universe.

All-versus-nothing proofs with n qubits distributed between m parties

NASA Astrophysics Data System (ADS)

Cabello, Adán; Moreno, Pilar

2010-04-01

All-versus-nothing (AVN) proofs show the conflict between Einstein, Podolsky, and Rosen’s elements of reality and the perfect correlations of some quantum states. Given an n-qubit state distributed between m parties, we provide a method with which to decide whether this distribution allows an m-partite AVN proof specific for this state using only single-qubit measurements. We apply this method to some recently obtained n-qubit m-particle states. In addition, we provide all inequivalent AVN proofs with less than nine qubits and a minimum number of parties.

Mistaken Identity and Mirror Images: Albert and Carl Einstein, Leiden and Berlin, Relativity and Revolution

NASA Astrophysics Data System (ADS)

van Dongen, Jeroen

2012-06-01

Albert Einstein accepted a "special" visiting professorship at the University of Leiden in the Netherlands in February 1920. Although his appointment should have been a mere formality, it took until October of that year before Einstein could occupy his special chair. Why the delay? The explanation involves a case of mistaken identity with Carl Einstein, Dadaist art, and a particular Dutch fear of revolutions. But what revolutions was one afraid of? The story of Einstein's Leiden chair throws new light on the reception of relativity and its creator in the Netherlands and in Germany.

Vortex based information storage in Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Dutton, Zachary; Ruostekoski, Janne

2004-05-01

Recent demonstrations of coherent optical storage in atomic clouds [1,2] have opened up new possibilities for both classical and quantum information storage. In parallel, there have been advances in the generation of Laguerre-Gaussian (LG) modes with angular momentum (optical vortices)[3] and applications of these modes to quantum information architectures based on a alphabets larger than the traditional two-state systems. Here we theoretically consider the storage of such LG modes in atomic Rb-87 Bose-Einstein condensates (BECs). An LG mode writes its vortex phase pattern into a two-component BEC vortex state. The angular momentum information can then be stored in the BEC and then efficiently read back onto the optical field by switching a control field on. We study the fidelity of the writing, storage, and read-out processes. We also consider applying this method to to the transfer of more complicated states, such as two-component vortex lattices, between two spatially distinct BECs. 1. C. Liu, Z. Dutton, C.H. Behroozi, and L.V. Hau, Nature 409, 490 (2001). 2. D.F. Phillips, A. Fleischhauer, A. Mair, R.L. Walsworth, and M.D. Lukin, Phys. Rev. Lett. 86, 783 (2001). 3. A. Vaziri, Gregor Weihs, and A. Zeilinger, cond-mat/0111033.

Einstein Online: A Web-based Course for K-12 Teachers from the American Museum of Natural History

NASA Astrophysics Data System (ADS)

Steiner, Robert

2004-05-01

Einstein Online: A Web-based Course for K-12 Teachers from the American Museum of Natural History Robert V. Steiner, Ph.D. Project Director, Seminars on Science American Museum of Natural History The American Museum of Natural History, in collaboration with Hebrew University and the Skirball Cultural Center, has created a major exhibit on Albert Einstein, including extensive coverage of his contributions to relativity, quantum mechanics and unified field theories as well as the social and political dimensions of his life. Leveraging the assets of this exhibit as well as the expertise of the Museum's Department of Astrophysics and its Education Department, a six-week online professional development course for K-12 teachers has been created, providing inquires into some of the frontiers of physics through rich media resources, facilitated discussion forums and assignments. The course, which requires only minimal Web access, offers a unique opportunity for teachers across the United States to explore modern physics guided by a working scientist and a skilled online facilitator. The course includes original essays by Museum scientists, images, video, simulations, web links and digital resources for classroom use. The course design, development, implementation and evaluation are reviewed.

Remembrance of Things Future: Prospective Memory in Laboratory, Workplace, and Everyday Settings

NASA Technical Reports Server (NTRS)

Dismukes, R. Key

2010-01-01

In this review, oriented to the human factors community, I will summarize and provide a perspective on recent research and theory on prospective memory. This will not be an exhaustive review of literature, which is already available in two excellent recent books that provide a wealth of detail on the current state of experimental research (Kliegel, McCaniel, & Einstein, 2008; McDaniel & Einstein, 2007; also see Brandimonte, Einstein, & McDaniel, 1996, for a still relevant overview of the field as it was emerging). Rather, I will explore the limits of existing experimental paradigms and theory, Vvilich, in my opinion, fail to capture some critical aspects of performance outside the laboratory. I will also review the relatively few studies in workplace and everyday settings and will discuss several studies that attempt to bridge between the bulk of experimental studies and these few naturalistic studies. Finally, I will describe countermeasures that can reduce vulnerability to forgetting to perform intended tasks, and I will propose a research agenda that would extend existing experimental and theoretical approaches and would support human factors practitioners by generating information on a wide range of issues relevant to prospective memory performance in natural settings.

Stationary axisymmetric four dimensional space-time endowed with Einstein metric

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

Hasanuddin; Departments of Physics, Tanjungpura University, Jl Ahmad Yani Pontianak 78124 Indonesia bobby@fi.itb.ac.id; Azwar, A.

In this paper, we construct Ernst equation from vacuum Einstein field equation for both zero and non-zero cosmological constant. In particular, we consider the case where the space-time admits axisymmetric using Boyer-Lindquist coordinates. This is called Kerr-Einstein solution describing a spinning black hole. Finally, we give a short discussion about the dynamics of photons on Kerr-Einstein space-time.

Deterministic joint remote preparation of an equatorial hybrid state via high-dimensional Einstein-Podolsky-Rosen pairs: active versus passive receiver

NASA Astrophysics Data System (ADS)

Bich, Cao Thi; Dat, Le Thanh; Van Hop, Nguyen; An, Nguyen Ba

2018-04-01

Entanglement plays a vital and in many cases non-replaceable role in the quantum network communication. Here, we propose two new protocols to jointly and remotely prepare a special so-called bipartite equatorial state which is hybrid in the sense that it entangles two Hilbert spaces with arbitrary different dimensions D and N (i.e., a type of entanglement between a quDit and a quNit). The quantum channels required to do that are however not necessarily hybrid. In fact, we utilize four high-dimensional Einstein-Podolsky-Rosen pairs, two of which are quDit-quDit entanglements, while the other two are quNit-quNit ones. In the first protocol the receiver has to be involved actively in the process of remote state preparation, while in the second protocol the receiver is passive as he/she needs to participate only in the final step for reconstructing the target hybrid state. Each protocol meets a specific circumstance that may be encountered in practice and both can be performed with unit success probability. Moreover, the concerned equatorial hybrid entangled state can also be jointly prepared for two receivers at two separated locations by slightly modifying the initial particles' distribution, thereby establishing between them an entangled channel ready for a later use.

Einstein-Podolsky-Rosen steering and Bell nonlocality of two macroscopic mechanical oscillators in optomechanical systems

NASA Astrophysics Data System (ADS)

Li, Jie; Zhu, Shi-Yao

2017-12-01

We investigate under which conditions quantum nonlocal manifestations such as Einstein-Podolsky-Rosen steering or Bell nonlocality can manifest themselves even at the macroscopic level of two mechanical resonators in optomechanical systems. We adopt the powerful scheme of reservoir engineering, implemented by driving a cavity mode with a properly chosen two-tone field, to prepare two mechanical oscillators in an entangled state. We show that large and robust (both one-way and two-way) steering could be achieved in the steady state with realistic parameters. We analyze the mechanism of the asymmetric nature of steering in our system of a two-mode Gaussian state. However, unlike steering, a Bell nonlocality is present under much more stringent conditions. We consider two types of measurements, displaced parity and on-off detection, respectively. We show that for both the measurements the Bell violation requires very low environmental temperature. For the parity detection, a large Bell violation is observed only in the transient state when the mechanical modes decouple from the optical mode and with extremely small cavity losses and mechanical damping. However, for the on-off detection, a moderate Bell violation is found in the steady state and is robust against cavity losses and mechanical damping. Although a Bell violation with parity detection seems extremely challenging to demonstrate experimentally, the conditions required for violating Bell inequalities with the on-off detection are much less demanding.

A comparative analysis of perspectives of Mileva Maric Einstein

NASA Astrophysics Data System (ADS)

Barnett, Carol C.

This dissertation examines the controversy surrounding Mileva Maric Einstein and the allegations subsequent to the publication of love letters during the time that Mileva Maric and Albert Einstein were students and during the early years of their marriage. It also examines the role of women in science from a historical perspective. Chapter One surveys the history of women in science from antiquity to the late nineteenth century and the patterns of gender related and restricting practices such as education, publication, the problem of mentoring and the issue of the lack of historical recognition. Chapter Two provides a comparative analyses between the lives of Mileva Maric Einstein and Marie Sklodowska Curie. Both had very similar social and educational backgrounds yet Marie Curie was able to work and publish jointly with her husband and received (although belatedly) international recognition for her work. On the other hand, Mileva Maric Einstein was never able to complete her degree and lived a life of obscurity and unfulfilled professional dreams. Both highly educated and intelligent women, but with drastically different outcomes in their professional and personal lives. Chapter Three examines the one book devoted to the life of Mileva Maric Einstein, Im Schatten Albert Einsteins: Das Tragische Leben der Mileva Einstein-Maric (In The Shadow of Albert Einstein: The Tragic Life of Mileva Maric), by Desanka Trbuhovic-Gjuric, Paul Haupt Publishers, 1985. It addresses the subjective as well as constructive and destructive criticisms of the various critical camps and provides examples of the statements made by the author which prompted a controversy within the academic and scientific communities. Appropriate responses are provided from various members of the scientific community to reflect the diversity of opinion and the intensity of the debate. Chapter Four addresses the problem of historicity and various interpretations of evidence which might suggest that the role of Mileva Maric was indeed more than just emotional spousal support for the scientific ideas of Albert Einstein. This chapter also details various lines and quotes from the book on Maric Einstein and also from the love letters shared between she and Albert Einstein to provide an indepth account of what evidence we have of possible professional collaboration.

Coherence, Abstraction, and Personal Involvement: Albert Einstein, Physicist and Humanist.

ERIC Educational Resources Information Center

Ne'eman, Yuval

1979-01-01

Reviews Einstein's main contributions to physics, and analyzes the importance of a coherent body of theory. Einstein's involvement in nonscientific issues such as nuclear disarmament is also included. (HM)

A modification of Einstein-Schrödinger theory that contains both general relativity and electrodynamics

NASA Astrophysics Data System (ADS)

Shifflett, J. A.

2008-08-01

We modify the Einstein-Schrödinger theory to include a cosmological constant Λ z which multiplies the symmetric metric, and we show how the theory can be easily coupled to additional fields. The cosmological constant Λ z is assumed to be nearly cancelled by Schrödinger’s cosmological constant Λ b which multiplies the nonsymmetric fundamental tensor, such that the total Λ = Λ z + Λ b matches measurement. The resulting theory becomes exactly Einstein-Maxwell theory in the limit as | Λ z | → ∞. For | Λ z | ~ 1/(Planck length)2 the field equations match the ordinary Einstein and Maxwell equations except for extra terms which are < 10-16 of the usual terms for worst-case field strengths and rates-of-change accessible to measurement. Additional fields can be included in the Lagrangian, and these fields may couple to the symmetric metric and the electromagnetic vector potential, just as in Einstein-Maxwell theory. The ordinary Lorentz force equation is obtained by taking the divergence of the Einstein equations when sources are included. The Einstein-Infeld-Hoffmann (EIH) equations of motion match the equations of motion for Einstein-Maxwell theory to Newtonian/Coulombian order, which proves the existence of a Lorentz force without requiring sources. This fixes a problem of the original Einstein-Schrödinger theory, which failed to predict a Lorentz force. An exact charged solution matches the Reissner-Nordström solution except for additional terms which are ~10-66 of the usual terms for worst-case radii accessible to measurement. An exact electromagnetic plane-wave solution is identical to its counterpart in Einstein-Maxwell theory.

Quantum statistical effects in the mass transport of interstitial solutes in a crystalline solid

NASA Astrophysics Data System (ADS)

Woo, C. H.; Wen, Haohua

2017-09-01

The impact of quantum statistics on the many-body dynamics of a crystalline solid at finite temperatures containing an interstitial solute atom (ISA) is investigated. The Mori-Zwanzig theory allows the many-body dynamics of the crystal to be formulated and solved analytically within a pseudo-one-particle approach using the Langevin equation with a quantum fluctuation-dissipation relation (FDR) based on the Debye model. At the same time, the many-body dynamics is also directly solved numerically via the molecular dynamics approach with a Langevin heat bath based on the quantum FDR. Both the analytical and numerical results consistently show that below the Debye temperature of the host lattice, quantum statistics significantly impacts the ISA transport properties, resulting in major departures from both the Arrhenius law of diffusion and the Einstein-Smoluchowski relation between the mobility and diffusivity. Indeed, we found that below one-third of the Debye temperature, effects of vibrations on the quantum mobility and diffusivity are both orders-of-magnitude larger and practically temperature independent. We have shown that both effects have their physical origin in the athermal lattice vibrations derived from the phonon ground state. The foregoing theory is tested in quantum molecular dynamics calculation of mobility and diffusivity of interstitial helium in bcc W. In this case, the Arrhenius law is only valid in a narrow range between ˜300 and ˜700 K. The diffusivity becomes temperature independent on the low-temperature side while increasing linearly with temperature on the high-temperature side.

Einstein's philosophy of physics

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

Seeger, R.J.

1979-09-01

Sources of Einstein's philosophical ideas are discussed. Einstein was indebted to Mach and Poincare, and espoused more or less a logical empiricism. He looked upon Nature as real, rational, and understandable, at least to an extent. (RWR)

Einstein Session of the Pontifical Academy.

ERIC Educational Resources Information Center

Science, 1980

1980-01-01

The texts of four speeches, given at the 1979 Einstein Session of the Pontifical Academy held in Rome, are presented. Each address relates to some aspect of the life and times of Albert Einstein. (SA)

Revealing Hidden Einstein-Podolsky-Rosen Nonlocality

NASA Astrophysics Data System (ADS)

Walborn, S. P.; Salles, A.; Gomes, R. M.; Toscano, F.; Souto Ribeiro, P. H.

2011-04-01

Steering is a form of quantum nonlocality that is intimately related to the famous Einstein-Podolsky-Rosen (EPR) paradox that ignited the ongoing discussion of quantum correlations. Within the hierarchy of nonlocal correlations appearing in nature, EPR steering occupies an intermediate position between Bell nonlocality and entanglement. In continuous variable systems, EPR steering correlations have been observed by violation of Reid’s EPR inequality, which is based on inferred variances of complementary observables. Here we propose and experimentally test a new criterion based on entropy functions, and show that it is more powerful than the variance inequality for identifying EPR steering. Using the entropic criterion our experimental results show EPR steering, while the variance criterion does not. Our results open up the possibility of observing this type of nonlocality in a wider variety of quantum states.

Route to non-Abelian quantum turbulence in spinor Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Mawson, Thomas; Ruben, Gary; Simula, Tapio

2015-06-01

We have studied computationally the collision dynamics of spin-2 Bose-Einstein condensates initially confined in a triple-well trap. Depending on the phase structure of the initial-state spinor wave function, the collision of the three condensate fragments produces one of many possible vortex-antivortex lattices, after which the system transitions to quantum turbulence. We find that the emerging vortex lattice structures can be described in terms of multiwave interference. We show that the three-fragment collisions can be used to systematically produce staggered vortex-antivortex honeycomb lattices of fractional-charge vortices, whose collision dynamics are known to be non-Abelian. Such condensate collider experiments could potentially be used as a controllable pathway to generating non-Abelian superfluid turbulence with networks of vortex rungs.

The Einstein tower : an intertexture of dynamic construction, relativity theory and astronomy

NASA Astrophysics Data System (ADS)

Hentschel, Klaus; Hentschel, Ann M.

This book focuses on the `Einstein Tower', an architecturally historic observatory built in Potsdam in 1920 to allow the German astronomer Erwin Finlay Freundlich to attempt to verify experimentally Einstein's general theory of relativity. Freundlich, who was the first German astronomer to show a genuine interest in Einstein's theory, managed to interest his architect friend Erich Mendelsohn in designing this unique building. To develop a full historical picture, the book interweaves several descriptive levels: the biography of Freundlich; the social context in which he interacted with teachers, co-workers, students, his patrons (including Einstein), and scientific opponents; the cognitive aspects of his attempts to verify Einstein's theory; the political milieu within the Berlin scientific research community; and a cross-national comparison of astrophysics. This is an interesting account of this unconventional tale in the history of science.

Albert Einstein's Magic Mountain: An Aarau Education*

NASA Astrophysics Data System (ADS)

Hunziker, Herbert

2015-03-01

For economic reasons, the electrotechnical factory J. Einstein & Cie. (co-owned by Albert Einstein's father Hermann) had to be closed in the summer of 1894. While Albert's parents emigrated to Italy to build a new existence, he remained in Munich to complete his studies at the Gymnasium. Left behind, however, he had a difficult time with what he considered the rigid educational practices at the Munich Luitpold-Gymnasium and quit without a diploma. The present article discusses Einstein's richly winding path to the Aargau Cantonal School (Switzerland), especially its history and educational philosophy during the time of his stay in Aarau. There, Einstein met some outstanding teachers, who could serve him as models of scholars and human beings. In spite of Einstein's distinct independence of mind, these personalities may well have had a significant influence on the alignment of his inner compass.

Liouvillian integrability of gravitating static isothermal fluid spheres

NASA Astrophysics Data System (ADS)

Iacono, Roberto; Llibre, Jaume

2014-10-01

We examine the integrability properties of the Einstein field equations for static, spherically symmetric fluid spheres, complemented with an isothermal equation of state, ρ = np. In this case, Einstein's equations can be reduced to a nonlinear, autonomous second order ordinary differential equation (ODE) for m/R (m is the mass inside the radius R) that has been solved analytically only for n = -1 and n = -3, yielding the cosmological solutions by De Sitter and Einstein, respectively, and for n = -5, case for which the solution can be derived from the De Sitter's one using a symmetry of Einstein's equations. The solutions for these three cases are of Liouvillian type, since they can be expressed in terms of elementary functions. Here, we address the question of whether Liouvillian solutions can be obtained for other values of n. To do so, we transform the second order equation into an equivalent autonomous Lotka-Volterra quadratic polynomial differential system in {R}^2, and characterize the Liouvillian integrability of this system using Darboux theory. We find that the Lotka-Volterra system possesses Liouvillian first integrals for n = -1, -3, -5, which descend from the existence of invariant algebraic curves of degree one, and for n = -6, a new solvable case, associated to an invariant algebraic curve of higher degree (second). For any other value of n, eventual first integrals of the Lotka-Volterra system, and consequently of the second order ODE for the mass function must be non-Liouvillian. This makes the existence of other solutions of the isothermal fluid sphere problem with a Liouvillian metric quite unlikely.

What Costs Do Reveal and Moving beyond the Cost Debate: Reply to Einstein and McDaniel (2010)

ERIC Educational Resources Information Center

Smith, Rebekah E.

2010-01-01

Einstein et al. (2005) predicted no cost to an ongoing task when a prospective memory task met certain criteria. Smith, Hunt, McVay, and McConnell (2007) used prospective memory tasks that met these criteria and found a cost to the ongoing task, contrary to Einstein et al.'s prediction. Einstein and McDaniel (2010) correctly noted that there are…

Renormalization of Einstein gravity through a derivative-dependent field redefinition

NASA Astrophysics Data System (ADS)

Slovick, Brian

2018-01-01

This work explores an alternative solution to the problem of renormalizability in Einstein gravity. In the proposed approach, Einstein gravity is transformed into the renormalizable theory of four-derivative gravity by applying a local field redefinition containing an infinite number of higher derivatives. It is also shown that the current-current amplitude is invariant with the field redefinition, and thus the unitarity of Einstein gravity is preserved.

Three-body interactions and the elastic constants of hcp solid 4He

NASA Astrophysics Data System (ADS)

Barnes, Ashleigh L.; Hinde, Robert J.

2017-09-01

The effect of three-body interactions on the elastic properties of hexagonal close packed solid 4He is investigated using variational path integral (VPI) Monte Carlo simulations. The solid's nonzero elastic constants are calculated, at T = 0 K and for a range of molar volumes from 7.88 cm3/mol to 20.78 cm3/mol, from the bulk modulus and the three pure shear constants C0, C66, and C44. Three-body interactions are accounted for using our recently reported perturbative treatment based on the nonadditive three-body potential of Cencek et al. Previous studies have attempted to account for the effect of three-body interactions on the elastic properties of solid 4He; however, these calculations have treated zero point motions using either the Einstein or Debye approximations, which are insufficient in the molar volume range where solid 4He is characterized as a quantum solid. Our VPI calculations allow for a more accurate treatment of the zero point motions which include atomic correlation. From these calculations, we find that agreement with the experimental bulk modulus is significantly improved when three-body interactions are considered. In addition, three-body interactions result in non-negligible differences in the calculated pure shear constants and nonzero elastic constants, particularly at higher densities, where differences of up to 26.5% are observed when three-body interactions are included. We compare to the available experimental data and find that our results are generally in as good or better agreement with experiment as previous theoretical investigations.

Universal Themes of Bose-Einstein Condensation

NASA Astrophysics Data System (ADS)

Proukakis, Nick P.; Snoke, David W.; Littlewood, Peter B.

2017-04-01

Foreword; List of contributors; Preface; Part I. Introduction: 1. Universality and Bose-Einstein condensation: perspectives on recent work D. W. Snoke, N. P. Proukakis, T. Giamarchi and P. B. Littlewood; 2. A history of Bose-Einstein condensation of atomic hydrogen T. Greytak and D. Kleppner; 3. Twenty years of atomic quantum gases: 1995-2015 W. Ketterle; 4. Introduction to polariton condensation P. B. Littlewood and A. Edelman; Part II. General Topics: Editorial notes; 5. The question of spontaneous symmetry breaking in condensates D. W. Snoke and A. J. Daley; 6. Effects of interactions on Bose-Einstein condensation R. P. Smith; 7. Formation of Bose-Einstein condensates M. J. Davis, T. M. Wright, T. Gasenzer, S. A. Gardiner and N. P. Proukakis; 8. Quenches, relaxation and pre-thermalization in an isolated quantum system T. Langen and J. Schmiedmayer; 9. Ultracold gases with intrinsic scale invariance C. Chin; 10. Berezinskii-Kosterlitz-Thouless phase of a driven-dissipative condensate N. Y. Kim, W. H. Nitsche and Y. Yamamoto; 11. Superfluidity and phase correlations of driven dissipative condensates J. Keeling, L. M. Sieberer, E. Altman, L. Chen, S. Diehl and J. Toner; 12. BEC to BCS crossover from superconductors to polaritons A. Edelman and P. B. Littlewood; Part III. Condensates in Atomic Physics: Editorial notes; 13. Probing and controlling strongly correlated quantum many-body systems using ultracold quantum gases I. Bloch; 14. Preparing and probing chern bands with cold atoms N. Goldman, N. R. Cooper and J. Dalibard; 15. Bose-Einstein condensates in artificial gauge fields L. J. LeBlanc and I. B. Spielman; 16. Second sound in ultracold atomic gases L. Pitaevskii and S. Stringari; 17. Quantum turbulence in atomic Bose-Einstein condensates N. G. Parker, A. J. Allen, C. F. Barenghi and N. P. Proukakis; 18. Spinor-dipolar aspects of Bose-Einstein condensation M. Ueda; Part IV. Condensates in Condensed Matter Physics: Editorial notes; 19. Bose-Einstein condensation of photons and grand-canonical condensate fluctuations J. Klaers and M. Weitz; 20. Laser operation and Bose-Einstein condensation: analogies and differences A. Chiocchetta, A. Gambassi and I. Carusotto; 21. Vortices in resonant polariton condensates in semiconductor microcavities D. N. Krizhanovskii, K. Guda, M. Sich, M. S. Skolnick, L. Dominici and D. Sanvitto; 22. Optical control of polariton condensates G. Christmann, P. G. Savvidis and J. J. Baumberg; 23. Disorder, synchronization and phase-locking in non-equilibrium Bose-Einstein condensates P. R. Eastham and B. Rosenow; 24. Collective topological excitations in 1D polariton quantum fluids H. Terças, D. D. Solnyshkov and G. Malpuech; 25. Microscopic theory of Bose-Einstein condensation of magnons at room temperature H. Salman, N. G. Berloff and S. O. Demokritov; 26. Spintronics and magnon Bose-Einstein condensation R. A. Duine, A. Brataas, S. A. Bender and Y. Tserkovnyak; 27. Spin-superfluidity and spin-current mediated non-local transport H. Chen and A. H. MacDonald; 28. Bose-Einstein condensation in quantum magnets C. Kollath, T. Giamarchi and C. Rüegg; Part V. Condensates in Astrophysics and Cosmology: Editorial notes; 29. Bose-Einstein condensates in neutron stars C. J. Pethick, T. Schäfer and A. Schwenk; 30. A simulated cosmological metric: the superfluid 3He condensate G. R. Pickett; 31. Cosmic axion Bose-Einstein condensation N. Banik and P. Sikivie; 32. Graviton BECs: a new approach to quantum gravity G. Dvali and C. Gomez; Universal Bose-Einstein condensation workshop; Index.

Distribution of eigenfrequencies for oscillations of the ground state in the Thomas-Fermi limit

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

Kevrekidis, P. G.; Pelinovsky, D. E.

In this work, we present a systematic derivation of the distribution of eigenfrequencies for oscillations of the ground state of a repulsive Bose-Einstein condensate in the semi-classical (Thomas-Fermi) limit. Our calculations are performed in one, two, and three-dimensional settings. Connections with the earlier work of Stringari, with numerical computations, and with theoretical expectations for invariant frequencies based on symmetry principles are also given.

EDITORIAL: Focus on Quantum Correlations in Tailored Matter

NASA Astrophysics Data System (ADS)

Muramatsu, Alejandro; Pfau, Tilman

2008-04-01

At low enough temperatures and at microscopic length scales the laws of quantum mechanics become apparent. The underlying superposition principle leads to interference phenomena for one degree of freedom and to the concept of entanglement for two and more. Entangled degrees of freedom are often correlated beyond their classically allowed correlation. These quantum correlations also appear in very large systems and are caused by strong interactions between the constituents. Strongly correlated forms of quantum matter became ubiquitous in condensed matter physics, with the discovery of heavy fermion materials, cuprates and other unconventional superconductors. Here the main players are electrons embedded in solid matter. But they also can be found in interacting quantum gases, where the main players are atoms. In the latter case the required temperatures for quantum correlations to appear are much lower. But in turn the length scales are larger and they can be embedded in well controlled potentials. A fascinating possibility offered by present day technologies is to tailor matter in order to induce the emergence of new phenomena by controlling quantum correlations. One of the routes leading to spectacular advances is the configuration of nanomaterials like quantum dots or quantum wires on the basis of semiconducting substrates that allow, e.g., to manipulate the Kondo effect or Luttinger liquids affecting transport properties through such nanostructures. Another quite different route with at the moment unlimited potential is offered by quantum optics and atomic physics, when implemented to bring quantum gases into the strongly interacting regime. This can be achieved by optical lattices leading to Mott-insulators, or to two dimensional systems displaying Kosterlitz-Thouless behavior in bosonic gases, or by Feshbach resonances, leading to fermionic systems with unconventional superfluid states like the Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) one. In spite of the very different experimental realizations leading to the two routes mentioned above, they share a common goal, namely achieving a deep understanding of quantum correlations that will ultimately allow to control them and possibly realize new forms of matter. They also share the flexibility that allows to increase the complexity in quantum correlations by joining in a controlled manner well understood building units and/or by regulating their coupling to the environment. It is under the common goal of understanding and controlling quantum correlations that we see the topics presented in this focus issue of New Journal of Physics, where both lines of development, that is on solid-state substrates or with quantum gases, give a timely view of the advances towards the above mentioned common goal. Focus on Quantum Correlations in Tailored Matter Contents Temperature changes when adiabatically ramping up an optical lattice Lode Pollet, Corinna Kollath, Kris Van Houcke and Matthias Troyer Numerical study of two-body correlation in a 1D lattice with perfect blockade B Sun and F Robicheaux Kinetic Monte Carlo modeling of dipole blockade in Rydberg excitation experiment Amodsen Chotia, Matthieu Viteau, Thibault Vogt, Daniel Comparat and Pierre Pillet Motion of Rydberg atoms induced by resonant dipole-dipole interactions C Ates, A Eisfeld and J M Rost Quantum coherence due to Bose-Einstein condensation of parametrically driven magnons S O Demokritov, V E Demidov, O Dzyapko, G A Melkov and A N Slavin Chaotic dynamics in spinor Bose-Einstein condensates J Kronjäger, K Sengstock and K Bongs Damped Bloch oscillations of Bose-Einstein condensates in disordered potential gradients S Drenkelforth, G Kleine Büning, J Will, T Schulte, N Murray, W Ertmer, L Santos and J J Arlt Rabi oscillations between ground and Rydberg states and van der Waals blockade in a mesoscopic frozen Rydberg gas M Reetz-Lamour, J Deiglmayr, T Amthor and M Weidemüller Excitations in two-component Bose gases A Kleine, C Kollath, I P McCulloch, T Giamarchi and U Schollwöck Exploring the growth of correlations in a quasi one-dimensional trapped Bose gas M Eckart, R Walser and W P Schleich How to fix a broken symmetry: quantum dynamics of symmetry restoration in a ferromagnetic Bose-Einstein condensate Bogdan Damski and Wojciech H Zurek Landau levels of cold atoms in non-Abelian gauge fields A Jacob, P Öhberg, G Juzeliunas and L Santos Atomic four-wave mixing via condensate collisions A Perrin, C M Savage, D Boiron, V Krachmalnicoff, C I Westbrook and K V Kheruntsyan Semifluxons in superconductivity and cold atomic gases R Walser, E Goldobin, O Crasser, D Koelle, R Kleiner and W P Schleich Disorder-induced trapping versus Anderson localization in Bose-Einstein condensates expanding in disordered potentials L Sanchez-Palencia, D Clément, P Lugan, P Bouyer and A Aspect Critical tunneling currents in the regime of bilayer excitons L Tiemann, W Dietsche, M Hauser and K von Klitzing Quantum phases of trapped ions in an optical lattice R Schmied, T Roscilde, V Murg, D Porras and J I Cirac Generation and detection of a spin entanglement in nonequilibrium quantum dots Stefan Legel, Jürgen König and Gerd Schön Slow light in inhomogeneous and transverse fields Leon Karpa and Martin Weitz FFLO state in 1-, 2- and 3-dimensional optical lattices combined with a non-uniform background potential T K Koponen, T Paananen, J-P Martikainen, M R Bakhtiari and P Törmä Geometry-dependent interplay of long- and short-range interactions in ultracold fermionic gases: models for condensed matter and astrophysics B Deb, G Kurizki and I E Mazets Fermionic renormalization group methods for transport through inhomogeneous Luttinger liquids V Meden, S Andergassen, T Enss, H Schoeller and K Schönhammer Luttinger hydrodynamics of confined one-dimensional Bose gases with dipolar interactions R Citro, S De Palo, E Orignac, P Pedri and M-L Chiofalo Towards deterministically controlled InGaAs/GaAs lateral quantum dot molecules L Wang, A Rastelli, S Kiravittaya, P Atkinson, F Ding, C C Bof Bufon, C Hermannstädter, M Witzany, G J Beirne, P Michler and O G Schmidt Effective parameters for weakly coupled Bose-Einstein condensates S Giovanazzi, J Esteve and M K Oberthaler Current statistics of correlated charge tunnelling through an impurity in a 1D wire Alexander Herzog and Ulrich Weiss Sideband cooling and coherent dynamics in a microchip multi-segmented ion trap Stephan A Schulz, Ulrich Poschinger, Frank Ziesel and Ferdinand Schmidt-Kaler The trapped two-dimensional Bose gas: from Bose-Einstein condensation to Berezinskii-Kosterlitz-Thouless physics Z Hadzibabic, P Krüger, M Cheneau, S P Rath and J Dalibard Dynamical protection of quantum computation from decoherence in laser-driven cold-ion and cold-atom systems Goren Gordon and Gershon Kurizki Spin-flip and spin-conserving optical transitions of the nitrogen-vacancy centre in diamond Ph Tamarat, N B Manson, J P Harrison, R L McMurtrie, A Nizovtsev, C Santori, R G Beausoleil, P Neumann, T Gaebel, F Jelezko, P Hemmer and J Wrachtrup Superconductivity in the attractive Hubbard model: functional renormalization group analysis R Gersch, C Honerkamp and W Metzner Quantum stability of Mott-insulator states of ultracold atoms in optical resonators Jonas Larson, Sonia Fernández-Vidal, Giovanna Morigi and Maciej Lewenstein

Conversations With Albert Einstein. II

ERIC Educational Resources Information Center

Shankland, R. S.

1973-01-01

Discusses Einstein's views on the role of Michelson-Morley, Fizeau, and Miller experiments in the development of relativity and his attitude toward the theories of new quantum mechanics. Indicates that Einstein's opposition to quantum mechanics is beyond dispute. (CC)

Annotations to D.B. Herrmann's contribution ``On Albert Einstein's political views'' (German Title: Anmerkungen zu D.B. Herrmanns Beitrag ``Über Albert Einsteins politische Ansichten'')

NASA Astrophysics Data System (ADS)

Grundmann, Siegfried

Referring to the Straus-Herrmann correspondence, we deal only with one aspect of the ``political Einstein'': his attitude towards Marx, Engels, Lenin and Stalin (who were in the past sometimes called the ``classics of Marxism-Leninism''). Einstein revered Marx, but condemned Stalin as a criminal. He also resisted attempts to be misused by representatives of ``dialectic materialism''.

[Never forget this in making your drawings and equations! A conversation with Albert Einstein on learning, teaching and the secrets of the world].

PubMed

Brunner, A

2009-03-01

Albert Einstein, the genius--this aspect often has been noted. A neglected aspect is Einstein's role as student and teacher. For this reason, Einstein's notes have been looked at once again. The selected original quotes are composed into the format of a fictive dialogue. The original context and coherence of his comments have thereby been respected carefully.

Diffusive motion with nonlinear friction: apparently Brownian.

PubMed

Goohpattader, Partho S; Chaudhury, Manoj K

2010-07-14

We study the diffusive motion of a small object placed on a solid support using an inertial tribometer. With an external bias and a Gaussian noise, the object slides accompanied with a fluctuation of displacement that exhibits unique characteristics at different powers of the noise. While it exhibits a fluidlike motion at high powers, a stick-slip motion occurs at a low power. Below a critical power, no motion is observed. The signature of a nonlinear friction is evident in this type of stochastic motion both in the reduced mobility in comparison to that governed by a linear kinematic (Stokes-Einstein-like) friction and in the non-Gaussian probability distribution of the displacement fluctuation. As the power of the noise increases, the effect of the nonlinearity appears to play a lesser role, so that the displacement fluctuation becomes more Gaussian. When the distribution is exponential, it also exhibits an asymmetry with its skewness increasing with the applied bias. A new finding of this study is that the stochastic velocities of the object are so poorly correlated that its diffusivity is much lower than either the linear or the nonlinear friction cases studied by de Gennes [J. Stat. Phys. 119, 953 (2005)]. The mobilities at different powers of the noise together with the estimated variances of velocity fluctuations follow an Einstein-like relation.

Extensions of the Einstein-Schrodinger non-symmetric theory of gravity

NASA Astrophysics Data System (ADS)

Shifflett, James A.

We modify the Einstein-Schrödinger theory to include a cosmological constant L z which multiplies the symmetric metric. The cosmological constant L z is assumed to be nearly cancelled by Schrödinger's cosmological constant L b which multiplies the nonsymmetric fundamental tensor, such that the total L = L z + L b matches measurement. The resulting theory becomes exactly Einstein-Maxwell theory in the limit as |L z | [arrow right] oo. For |L z | ~ 1/(Planck length) 2 the field equations match the ordinary Einstein and Maxwell equations except for extra terms which are < 10 -16 of the usual terms for worst-case field strengths and rates-of-change accessible to measurement. Additional fields can be included in the Lagrangian, and these fields may couple to the symmetric metric and the electromagnetic vector potential, just as in Einstein-Maxwell theory. The ordinary Lorentz force equation is obtained by taking the divergence of the Einstein equations when sources are included. The Einstein- Infeld-Hoffmann (EIH) equations of motion match the equations of motion for Einstein-Maxwell theory to Newtonian/Coulombian order, which proves the existence of a Lorentz force without requiring sources. An exact charged solution matches the Reissner-Nordström solution except for additional terms which are ~ 10 -66 of the usual terms for worst-case radii accessible to measurement. An exact electromagnetic plane-wave solution is identical to its counterpart in Einstein-Maxwell theory. Peri-center advance, deflection of light and time delay of light have a fractional difference of < 10 -56 compared to Einstein-Maxwell theory for worst-case parameters. When a spin-1/2 field is included in the Lagrangian, the theory gives the ordinary Dirac equation, and the charged solution results in fractional shifts of < 10 -50 in Hydrogen atom energy levels. Newman-Penrose methods are used to derive an exact solution of the connection equations, and to show that the charged solution is Petrov type- D like the Reissner-Nordström solution. The Newman-Penrose asymptotically flat [Special characters omitted.] (1/ r 2 ) expansion of the field equations is shown to match Einstein-Maxwell theory. Finally we generalize the theory to non-Abelian fields, and show that a special case of the resulting theory closely approximates Einstein-Weinberg-Salam theory.

On static black holes solutions in Einstein and Einstein-Gauss-Bonnet gravity with topology [Formula: see text].

PubMed

Dadhich, Naresh; Pons, Josep M

We study static black hole solutions in Einstein and Einstein-Gauss-Bonnet gravity with the topology of the product of two spheres, [Formula: see text], in higher dimensions. There is an unusual new feature of the Gauss-Bonnet black hole: the avoidance of a non-central naked singularity prescribes a mass range for the black hole in terms of [Formula: see text]. For an Einstein-Gauss-Bonnet black hole a limited window of negative values for [Formula: see text] is also permitted. This topology encompasses black strings, branes, and generalized Nariai metrics. We also give new solutions with the product of two spheres of constant curvature.

Laboratory measurements of the millimeter-wave spectra of calcium isocyanide

NASA Astrophysics Data System (ADS)

Steimle, Timothy C.; Saito, Shuji; Takano, Shuro

1993-06-01

The ground state of CaNC is presently characterized by mm-wave spectroscopy, using a standard Hamiltonian linear molecule model to analyze the spectrum. The resulting spectroscopic parameters were used to predict the transition frequencies and Einstein A-coefficients, which should make possible a quantitative astrophysical search for CaNC.

Tunable tunneling: stationary states of the Bose-Einstein condensate in traps of finite depth

NASA Astrophysics Data System (ADS)

Mahmud, K. W.

2001-03-01

The complete set of stationary solutions in a finite square well for repulsive and attractive Bose-Einstein condensates was obtained. An immediate application of these different solution types is tunable tunneling. Magnetically tunable Feshbach resonances [1] can change the scattering length of certain atoms, such as ^85Rb , by several orders of magnitude, including the sign, and thereby also change the mean field nonlinearity term of the equation and the tunneling of the wavefunction. Extending earlier work on the solutions of the Gross-Pitaevskii equation under box and periodic boundary conditions [2,3], we find both linear-type localized solutions and uniquely nonlinear partially localized states where the tails of the wavefunction become nonzero at infinity when the nonlinearity increases. The tunneling and localization of the wavefunction therefore becomes an external experimentally controllable parameter. PACS numbers: 03.75.Fi, 05.30.Jp, 67.40.-w 1. Ph. Courteille et al., Phys. Rev. Lett. 81, 69 (1998) 2, 3. L. D. Carr, C. W. Clark, and W. P. Reinhardt, Phys. Rev. A 62, 063610 and 063611 (2000)

Equilibrium vortex lattices of a binary rotating atomic Bose–Einstein condensate with unequal atomic masses

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

Dong, Biao; Wang, Lin-Xue; Chen, Guang-Ping

We perform a detailed numerical study of the equilibrium ground-state structures of a binary rotating Bose–Einstein condensate with unequal atomic masses. Our results show that the ground-state distribution and its related vortex configurations are complex events that differ markedly depending strongly on the strength of rotation frequency, as well as on the ratio of atomic masses. We also discuss the structures and radii of the clouds, the number and the size of the core region of the vortices, as a function of the rotation frequency, and of the ratio of atomic masses, and the analytical results agree well with ourmore » numerical simulations. This work may open an alternate way in the quantum control of the binary rotating quantum gases with unequal atomic masses. - Highlights: • A binary quantum gases with unequal atomic masses is considered. • Effects of the ratio of atomic masses and rotation frequency are discussed in full parameter space. • The detailed information about both the cloud and vortices are also discussed.« less

When champions meet: Rethinking the Bohr-Einstein debate

NASA Astrophysics Data System (ADS)

Landsman, N. P.

Einstein's philosophy of physics (as clarified by Fine, Howard, and Held) was predicated on his Trennungsprinzip, a combination of separability and locality, without which he believed objectification, and thereby "physical thought" and "physical laws', to be impossible. Bohr's philosophy (as elucidated by Hooker, Scheibe, Folse, Howard, Held, and others), on the other hand, was grounded in a seemingly different doctrine about the possibility of objective knowledge, namely the necessity of classical concepts. In fact, it follows from Raggio's Theorem in algebraic quantum theory that-within an appropriate class of physical theories-suitable mathematical translations of the doctrines of Bohr and Einstein are equivalent. Thus-upon our specific formalization-quantum mechanics accommodates Einstein's Trennungsprinzip if and only if it is interpreted à la Bohr through classical physics. Unfortunately, the protagonists themselves failed to discuss their differences in this constructive way, since their debate was dominated by Einstein's ingenious but ultimately flawed attempts to establish the "incompleteness" of quantum mechanics. This aspect of their debate may still be understood and appreciated, however, as reflecting a much deeper and insurmountable disagreement between Bohr and Einstein about the knowability of Nature. Using the theological controversy on the knowability of God as a analogy, we can say that Einstein was a Spinozist, whereas Bohr could be said to be on the side of Maimonides. Thus Einstein's off-the-cuff characterization of Bohr as a 'Talmudic philosopher' was spot-on.

Centenarian Einstein

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

None

2006-05-02

Commemoration of Albert Einstein with 4 speakers to honor his memory: Professor Weisskopf speaks about the scientifically engaged man. Daniel Amati speaks about the climate of the domain of physics during the 1920s, and Sergio Fubini speaks about the scientific hour of Einstein and Berob.

Centenarian Einstein

ScienceCinema

None

2018-05-18

Commemoration of Albert Einstein with 4 speakers to honor his memory: Professor Weisskopf speaks about the scientifically engaged man. Daniel Amati speaks about the climate of the domain of physics during the 1920s, and Sergio Fubini speaks about the scientific hour of Einstein and Berob.

Albert Einstein 1879-1955.

ERIC Educational Resources Information Center

Physics Today, 1979

1979-01-01

Celebrates the centennial of Einstein's birth with an eight-page pictorial biography and two special articles: (1) Einstein the catalyst; and (2) Unitary field theories. His special and general theories of relativity and his contributions to quantum physics and other topics are also presented. (HM)

Einstein's 1917 static model of the universe: a centennial review

NASA Astrophysics Data System (ADS)

O'Raifeartaigh, Cormac; O'Keeffe, Michael; Nahm, Werner; Mitton, Simon

2017-08-01

We present a historical review of Einstein's 1917 paper ` Cosmological Considerations in the General Theory of Relativity' to mark the centenary of a key work that set the foundations of modern cosmology. We find that the paper followed as a natural next step after Einstein's development of the general theory of relativity and that the work offers many insights into his thoughts on relativity, astronomy and cosmology. Our review includes a description of the observational and theoretical background to the paper; a paragraph-by-paragraph guided tour of the work; a discussion of Einstein's views of issues such as the relativity of inertia, the curvature of space and the cosmological constant. Particular attention is paid to little-known aspects of the paper such as Einstein's failure to test his model against observation, his failure to consider the stability of the model and a mathematical oversight concerning his interpretation of the role of the cosmological constant. We recall the response of theorists and astronomers to Einstein's cosmology in the context of the alternate models of the universe proposed by Willem de Sitter, Alexander Friedman and Georges Lemaître. Finally, we consider the relevance of the Einstein World in today's `emergent' cosmologies.

The collected papers of Albert Einstein. Volume 2. The Swiss years: Writings, 1900-1909

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

Stachel, J.; Cassidy, D.C.; Renn, J.

1989-01-01

This second volume of the papers of Albert Einstein chronologically presents published articles, unpublished papers, research and lecture notes, reviews, and patent applications for the period 1900-1909 during which time Einstein had a two-year period of short-term employment and a permanent position at the Swiss Patent Office in Bern. There are 62 published documents reproduced. The writings of this period deal with seven general themes: molecular forces, the foundation of statistical physics, the quantum hypothesis, determining molecular dimensions, Brownian movement, the theory of relativity, and the electrodynamics of moving media. The book also presents all available letters written by Einsteinmore » along with all significant letters sent to him and many important third-party letters written about him. The editors have added substantial introduction and a set of eight editorial notes that place Einstein's writings within their immediate scientific context. Footnotes to Einstein texts designed to illuminate the sources of scientific problems that Einstein confronted and the ideas and techniques with which he addressed them have been added by the editors. A comprehensive index to Einstein's early writings is provided.« less

Large D-2 theory of superconducting fluctuations in a magnetic field and its application to iron pnictides.

PubMed

Murray, James M; Tesanović, Zlatko

2010-07-16

A Ginzburg-Landau approach to fluctuations of a layered superconductor in a magnetic field is used to show that the interlayer coupling can be incorporated within an interacting self-consistent theory of a single layer, in the limit of a large number of neighboring layers. The theory exhibits two phase transitions-a vortex liquid-to-solid transition is followed by a Bose-Einstein condensation into the Abrikosov lattice-illustrating the essential role of interlayer coupling. By using this theory, explicit expressions for magnetization, specific heat, and fluctuation conductivity are derived. We compare our results with recent experimental data on the iron-pnictide superconductors.

Conditionally Teleported States Using Optical Squeezers and Photon Counting

NASA Astrophysics Data System (ADS)

Fan, Hong-Yi; Fan, Yue; Cheng, Hai-Ling

2002-04-01

By virtue of the neat expression of the two-mode squeezing operator in the Einstein, Podolsky and Rosen entangled state representation, we provide a new approach for discussing the teleportation scheme using optical squeezers and photon counting devices. We derive the explicit form of the teleported states, so that the conditional property of teleportation and teleportation fidelity of this protocol can be seen more clearly. The derivation is concise. The project supported by the President Foundation of the Chinese Academy of Sciences and National Natural Science Foundation of China

Einstein on Race and Racism, presented by Fred Jerome and Rodger Taylor

NASA Astrophysics Data System (ADS)

Jerome, Fred; Taylor, Rodger

2007-10-01

It is little-known that physicist Albert Einstein strongly held the view that ``Racism is America's worst disease.'' Einstein was active in the fight against racism from the 1930's until his death in 1955. Included among his friends were a number of important Afro-American figures, including the educator W.E.B. DuBois, the actor and basso profundo singer Paul Robeson, and the soprano Marian Anderson. Based on the authors' work ``Einstein on Race and Racism.''

Emerging applications of spark plasma sintering in all solid-state lithium-ion batteries and beyond

NASA Astrophysics Data System (ADS)

Zhu, Hongzheng; Liu, Jian

2018-07-01

Solid-state batteries have received increasing attention due to their high safety aspect and high energy and power densities. However, the development of solid-state batteries is hindered by inferior solid-solid interfaces between the solid-state electrolyte and electrode, which cause high interfacial resistance, reduced Li-ion and electron transfer rate, and limited battery performance. Recently, spark plasma sintering (SPS) is emerging as a promising technique for fabricating solid-state electrolyte and electrode pellets with clean and intimate solid-solid interfaces. During the SPS process, the unique reaction mechanism through the combination of current, pressure and high heating rate allow the formation of desirable solid-solid interfaces between active material particles. Herein, this work focuses on the overview of the application of SPS for fabricating solid-state electrolyte and electrode in all solid-state Li-ion batteries, and beyond, such as solid-state Li-S and Na-ion batteries. The correlations among SPS parameters, interfacial resistance, and electrochemical properties of solid-state electrolytes and electrodes are discussed for different material systems. In the end, we point out future opportunities and challenges associated with SPS application in the hot area of solid-state batteries. It is expected that this timely review will stimulate more fundamental and applied research in the development of solid-state batteries by SPS.

Integrable pair-transition-coupled nonlinear Schrödinger equations.

PubMed

Ling, Liming; Zhao, Li-Chen

2015-08-01

We study integrable coupled nonlinear Schrödinger equations with pair particle transition between components. Based on exact solutions of the coupled model with attractive or repulsive interaction, we predict that some new dynamics of nonlinear excitations can exist, such as the striking transition dynamics of breathers, new excitation patterns for rogue waves, topological kink excitations, and other new stable excitation structures. In particular, we find that nonlinear wave solutions of this coupled system can be written as a linear superposition of solutions for the simplest scalar nonlinear Schrödinger equation. Possibilities to observe them are discussed in a cigar-shaped Bose-Einstein condensate with two hyperfine states. The results would enrich our knowledge on nonlinear excitations in many coupled nonlinear systems with transition coupling effects, such as multimode nonlinear fibers, coupled waveguides, and a multicomponent Bose-Einstein condensate system.

Revealing hidden Einstein-Podolsky-Rosen nonlocality.

PubMed

Walborn, S P; Salles, A; Gomes, R M; Toscano, F; Souto Ribeiro, P H

2011-04-01

Steering is a form of quantum nonlocality that is intimately related to the famous Einstein-Podolsky-Rosen (EPR) paradox that ignited the ongoing discussion of quantum correlations. Within the hierarchy of nonlocal correlations appearing in nature, EPR steering occupies an intermediate position between Bell nonlocality and entanglement. In continuous variable systems, EPR steering correlations have been observed by violation of Reid's EPR inequality, which is based on inferred variances of complementary observables. Here we propose and experimentally test a new criterion based on entropy functions, and show that it is more powerful than the variance inequality for identifying EPR steering. Using the entropic criterion our experimental results show EPR steering, while the variance criterion does not. Our results open up the possibility of observing this type of nonlocality in a wider variety of quantum states. © 2011 American Physical Society

Alternative Interpretation of Low-Energy Nuclear Reaction Processes with Deuterated Metals Based on the Bose-Einstein Condensation Mechanism

NASA Astrophysics Data System (ADS)

Kim, Yeong E.; Passell, Thomas O.

2006-02-01

Recently, a generalization of the Bose-Einstein condensation (BEC) mechanism has been made to a ground-state mixture of two different species of positively charged bosons in harmonic traps. The theory has been used to describe (D + Li) reactions in the low energy nuclear reaction (LENR) processes in condensed matter and predicts that the (D + Li) reaction rates can be larger than (D + D) reaction rates by as much as a factor of ~50, implying that (D + Li) reactions may be occuring in addition to the (D + D) reactions. A survey of the existing data from LENR experiments is carried out to check the validity of the theoretical prediction. We conclude that there is compelling experimental evidence which support the theoretical prediction. New experimental tests of the theoretical prediction are suggested.

Dark soliton beats in the time-varying background of Bose-Einstein condensates

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

Wu Lei; Li Lu; Zhang Jiefang

2009-07-15

We investigate the dynamics of dark solitons in one-dimensional Bose-Einstein condensates. In the large particle limit, by introducing the lens-type transformation, we find that the macroscopic wave function evolves self-similarly when its initial profile strays from that of the equilibrium state, which provides a time-varying background for the propagation of dark solitons. The interaction of dark solitons with this kind of background is studied both analytically and numerically. We find that the center-of-mass motion of the dark soliton is deeply affected by the time-varying background, and the beating phenomena of dark soliton emerge when the intrinsic frequency of the darkmore » soliton approaches that of the background. Lastly, we investigate the propagation of dark solitons in the freely expanding background.« less

Black p-branes versus black holes in non-asymptotically flat Einstein-Yang-Mills theory

NASA Astrophysics Data System (ADS)

Habib Mazharimousavi, S.; Halilsoy, M.

2016-09-01

We present a class of non-asymptotically flat (NAF) charged black p-branes (BpB) with p-compact dimensions in higher-dimensional Einstein-Yang-Mills theory. Asymptotically the NAF structure manifests itself as an anti-de sitter spacetime. We determine the total mass/energy enclosed in a thin shell located outside the event horizon. By comparing the entropies of BpB with those of black holes in the same dimensions we derive transition criteria between the two types of black objects. Given certain conditions satisfied, our analysis shows that BpB can be considered excited states of black holes. An event horizon r+ versus charge square Q2 plot for the BpB reveals such a transition where r+ is related to the horizon radius rh of the black hole (BH) both with the common charge Q.

Adiabatic and Non-adiabatic quenches in a Spin-1 Bose Einstein Condensate

NASA Astrophysics Data System (ADS)

Boguslawski, Matthew; Hebbe Madhusudhana, Bharath; Anquez, Martin; Robbins, Bryce; Barrios, Maryrose; Hoang, Thai; Chapman, Michael

2016-05-01

A quantum phase transition (QPT) is observed in a wide range of phenomena. We have studied the dynamics of a spin-1 ferromagnetic Bose-Einstein condensate for both adiabatic and non-adiabatic quenches through a QPT. At the quantum critical point (QCP), finite size effects lead to a non-zero gap, which makes an adiabatic quench possible through the QPT. We experimentally demonstrate such a quench, which is forbidden at the mean field level. For faster quenches through the QCP, the vanishing energy gap causes the reaction timescale of the system to diverge, preventing the system from adiabatically following the ground state. We measure the temporal evolution of the spin populations for different quench speeds and determine the exponents characterizing the scaling of the onset of excitations, which are in good agreement with the predictions of Kibble-Zurek mechanism.

Critical behavior of the ideal-gas Bose-Einstein condensation in the Apollonian network.

PubMed

de Oliveira, I N; dos Santos, T B; de Moura, F A B F; Lyra, M L; Serva, M

2013-08-01

We show that the ideal Boson gas displays a finite-temperature Bose-Einstein condensation transition in the complex Apollonian network exhibiting scale-free, small-world, and hierarchical properties. The single-particle tight-binding Hamiltonian with properly rescaled hopping amplitudes has a fractal-like energy spectrum. The energy spectrum is analytically demonstrated to be generated by a nonlinear mapping transformation. A finite-size scaling analysis over several orders of magnitudes of network sizes is shown to provide precise estimates for the exponents characterizing the condensed fraction, correlation size, and specific heat. The critical exponents, as well as the power-law behavior of the density of states at the bottom of the band, are similar to those of the ideal Boson gas in lattices with spectral dimension d(s)=2ln(3)/ln(9/5)~/=3.74.

The cerebral cortex of Albert Einstein: a description and preliminary analysis of unpublished photographs.

PubMed

Falk, Dean; Lepore, Frederick E; Noe, Adrianne

2013-04-01

Upon his death in 1955, Albert Einstein's brain was removed, fixed and photographed from multiple angles. It was then sectioned into 240 blocks, and histological slides were prepared. At the time, a roadmap was drawn that illustrates the location within the brain of each block and its associated slides. Here we describe the external gross neuroanatomy of Einstein's entire cerebral cortex from 14 recently discovered photographs, most of which were taken from unconventional angles. Two of the photographs reveal sulcal patterns of the medial surfaces of the hemispheres, and another shows the neuroanatomy of the right (exposed) insula. Most of Einstein's sulci are identified, and sulcal patterns in various parts of the brain are compared with those of 85 human brains that have been described in the literature. To the extent currently possible, unusual features of Einstein's brain are tentatively interpreted in light of what is known about the evolution of higher cognitive processes in humans. As an aid to future investigators, these (and other) features are correlated with blocks on the roadmap (and therefore histological slides). Einstein's brain has an extraordinary prefrontal cortex, which may have contributed to the neurological substrates for some of his remarkable cognitive abilities. The primary somatosensory and motor cortices near the regions that typically represent face and tongue are greatly expanded in the left hemisphere. Einstein's parietal lobes are also unusual and may have provided some of the neurological underpinnings for his visuospatial and mathematical skills, as others have hypothesized. Einstein's brain has typical frontal and occipital shape asymmetries (petalias) and grossly asymmetrical inferior and superior parietal lobules. Contrary to the literature, Einstein's brain is not spherical, does not lack parietal opercula and has non-confluent Sylvian and inferior postcentral sulci.

Progress and prospect on failure mechanisms of solid-state lithium batteries

NASA Astrophysics Data System (ADS)

Ma, Jun; Chen, Bingbing; Wang, Longlong; Cui, Guanglei

2018-07-01

By replacing traditional liquid organic electrolyte with solid-state electrolyte, the solid-state lithium batteries powerfully come back to the energy storage field due to their eminent safety and energy density. In recent years, a variety of solid-state lithium batteries based on excellent solid-state electrolytes are developed. However, the performance degradation of solid-state lithium batteries during cycling and storing is still a serious challenge for practical application. Therefore, this review summarizes the research progress of solid-state lithium batteries from the perspectives of failure phenomena and failure mechanisms. Additionally, the development of methodologies on studying the failure mechanisms of solid-state lithium batteries is also reviewed. Moreover, some perspectives on the remaining questions for understanding the failure behaviors and achieving long cycle life, high safety and high energy density solid-state lithium batteries are presented. This review will help researchers to recognize the status of solid-state lithium batteries objectively and attract much more research interest in conquering the failure issues of solid-state lithium batteries.

The happiest thought of Einstein's life.

NASA Astrophysics Data System (ADS)

Heller, M.

It is a commonly told story that Einstein formulated his famous principle of equivalence when thinking about what happens in a freely falling elevator, and that it was an original idea of his genius distinguished by the rare capability to see deep problems in the most ordinary things. In the reading of Einstein's and Ernst Mach's works the author has discovered that it was not a physicist in an elevator which led to the principle of equivalence but rather somebody falling from a roof; moreover, the idea behind the principle was not invented by Einstein himself but rather read by him from the book by Mach entitled The Science of Mechanics. The influence this book had on young Einstein is very well known.

Astronomical and Cosmological Symbolism in Art Dedicated to Newton and Einstein

NASA Astrophysics Data System (ADS)

Sinclair, R.

2013-04-01

Separated by two and a half centuries, Isaac Newton (1642-1727) and Albert Einstein (1879-1955) had profound impacts on our understanding of the universe. Newton established our understanding of universal gravitation, which was recast almost beyond recognition by Einstein. Both discovered basic patterns behind astronomical phenomena and became the best-known scientists of their respective periods. I will describe here how artists of the 18th and 20th centuries represented the achievements of Newton and Einstein. Representations of Newton express reverence, almost an apotheosis, portraying him as the creator of the universe. Einstein, in a different age, is represented often as a comic figure, and only rarely do we find art that hints at the profound view of the universe he developed.

Einstein's conversion from his static to an expanding universe

NASA Astrophysics Data System (ADS)

Nussbaumer, Harry

2014-02-01

In 1917 Einstein initiated modern cosmology by postulating, based on general relativity, a homogenous, static, spatially curved universe. To counteract gravitational contraction he introduced the cosmological constant. In 1922 Alexander Friedman showed that Albert Einstein's fundamental equations also allow dynamical worlds, and in 1927 Georges Lemaître, backed by observational evidence, concluded that our universe was expanding. Einstein impetuously rejected Friedman's as well as Lemaître's findings. However, in 1931 he retracted his former static model in favour of a dynamic solution. This investigation follows Einstein on his hesitating path from a static to the expanding universe. Contrary to an often advocated belief the primary motive for his switch was not observational evidence, but the realisation that his static model was unstable.

Solid oxide fuel cells fueled with reducible oxides

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

Chuang, Steven S.; Fan, Liang Shih

A direct-electrochemical-oxidation fuel cell for generating electrical energy includes a cathode provided with an electrochemical-reduction catalyst that promotes formation of oxygen ions from an oxygen-containing source at the cathode, a solid-state reduced metal, a solid-state anode provided with an electrochemical-oxidation catalyst that promotes direct electrochemical oxidation of the solid-state reduced metal in the presence of the oxygen ions to produce electrical energy, and an electrolyte disposed to transmit the oxygen ions from the cathode to the solid-state anode. A method of operating a solid oxide fuel cell includes providing a direct-electrochemical-oxidation fuel cell comprising a solid-state reduced metal, oxidizing themore » solid-state reduced metal in the presence of oxygen ions through direct-electrochemical-oxidation to obtain a solid-state reducible metal oxide, and reducing the solid-state reducible metal oxide to obtain the solid-state reduced metal.« less

Einstein Up in Smoke

NASA Astrophysics Data System (ADS)

Lisle, John

2016-01-01

Albert Einstein's biographers have not explained why he developed the abdominal aortic aneurysm that led to his death. Early conjectures proposed that it was caused by syphilis, without accurate evidence. The present article gives evidence to the contrary, and argues that the principal cause of Einstein's death was smoking.

Einstein's First Steps Toward General Relativity: Gedanken Experiments and Axiomatics

NASA Astrophysics Data System (ADS)

Miller, A. I.

1999-03-01

Albert Einstein's 1907 Jahrbuch paper is an extraordinary document because it contains his first steps toward generalizing the 1905 relativity theory to include gravitation. Ignoring the apparent experimental disconfirmation of the 1905 relativity theory and his unsuccessful attempts to generalize the mass-energy equivalence, Einstein boldly raises the mass-energy equivalence to an axiom, invokes equality between gravitational and inertial masses, and then postulates the equivalence between a uniform gravitational field and an oppositely directed constant acceleration, the equivalence principle. How did this come about? What is at issue is scientific creativity. This necessitates broadening historical analysis to include aspects of cognitive science such as the role of visual imagery in Einstein's thinking, and the relation between conscious and unconscious modes of thought in problem solving. This method reveals the catalysts that sparked a Gedanken experiment that occurred to Einstein while working on the Jahrbuch paper. A mental model is presented to further explore Einstein's profound scientific discovery.

What Costs Do Reveal and Moving Beyond the Cost Debate: Reply to Einstein and McDaniel (in press)

PubMed Central

Smith, Rebekah E.

2010-01-01

Einstein et al., (2005) predicted no cost to an ongoing task when a prospective memory task meet certain criteria. Smith et al. (2007) used prospective memory tasks that met these criteria and found a cost to the ongoing task, contrary to Einstein et al.'s prediction. Einstein and McDaniel (in press) correctly note that there are limitations to using ongoing task performance as a measure of the processes that contribute to prospective memory performance, however, the alternatives suggested by Einstein and McDaniel all focus on ongoing task performance and therefore do not move beyond the cost debate. This article describes why the Smith et al. findings are important, provides recommendations for issues to consider when investigating cost, and discusses individual cost measures. Finally, noting the blurry distinction between Einstein and McDaniel's description of the reflexive associative processes and preparatory attentional processes and difficulties in extending the multiprocess view to nonlaboratory tasks, suggestions are made for moving beyond the cost debate. PMID:20852726

Nambu at Work

NASA Astrophysics Data System (ADS)

Freund, Peter G. O.

Yoichiro Nambu, whose life and seminal contributions to Physics we celebrate here, went in 1952 to the Institute for Advanced Study in Princeton. Shortly after his arrival there, J. Robert Oppenheimer, the Institute's director, put Yoichiro and the other new arrivals on notice that though Albert Einstein was a professor at the Institute, and therefore had an office there, nobody was to disturb the great man without first receiving special permission personally from Oppie. Most people would spend a year or two in the same building with Einstein and then spend a whole lifetime regretting not to have met him. Yoichiro decided that he will meet Einstein, no matter what Oppie says. He knew Bruria Kaufmann, Einstein's assistant at that time, and with her help got to visit the great physicist. Einstein was very friendly and visibly happy that finally one of the young people had bothered to visit him. Einstein asked Yoichiro what was going on in particle physics, and was rather skeptical about separate nucleon and meson fields for which he saw no deeper reason...

Bose–Einstein condensation temperature of finite systems

NASA Astrophysics Data System (ADS)

Xie, Mi

2018-05-01

In studies of the Bose–Einstein condensation of ideal gases in finite systems, the divergence problem usually arises in the equation of state. In this paper, we present a technique based on the heat kernel expansion and zeta function regularization to solve the divergence problem, and obtain the analytical expression of the Bose–Einstein condensation temperature for general finite systems. The result is represented by the heat kernel coefficients, where the asymptotic energy spectrum of the system is used. Besides the general case, for systems with exact spectra, e.g. ideal gases in an infinite slab or in a three-sphere, the sums of the spectra can be obtained exactly and the calculation of corrections to the critical temperatures is more direct. For a system confined in a bounded potential, the form of the heat kernel is different from the usual heat kernel expansion. We show that as long as the asymptotic form of the global heat kernel can be found, our method works. For Bose gases confined in three- and two-dimensional isotropic harmonic potentials, we obtain the higher-order corrections to the usual results of the critical temperatures. Our method can also be applied to the problem of generalized condensation, and we give the correction of the boundary on the second critical temperature in a highly anisotropic slab.

Mathematical issues in eternal inflation

NASA Astrophysics Data System (ADS)

Singh Kohli, Ikjyot; Haslam, Michael C.

2015-04-01

In this paper, we consider the problem of the existence and uniqueness of solutions to the Einstein field equations for a spatially flat Friedmann-Lemaître-Robertson-Walker universe in the context of stochastic eternal inflation, where the stochastic mechanism is modelled by adding a stochastic forcing term representing Gaussian white noise to the Klein-Gordon equation. We show that under these considerations, the Klein-Gordon equation actually becomes a stochastic differential equation. Therefore, the existence and uniqueness of solutions to Einstein’s equations depend on whether the coefficients of this stochastic differential equation obey Lipschitz continuity conditions. We show that for any choice of V(φ ), the Einstein field equations are not globally well-posed, hence, any solution found to these equations is not guaranteed to be unique. Instead, the coefficients are at best locally Lipschitz continuous in the physical state space of the dynamical variables, which only exist up to a finite explosion time. We further perform Feller’s explosion test for an arbitrary power-law inflaton potential and prove that all solutions to the Einstein field equations explode in a finite time with probability one. This implies that the mechanism of stochastic inflation thus considered cannot be described to be eternal, since the very concept of eternal inflation implies that the process continues indefinitely. We therefore argue that stochastic inflation based on a stochastic forcing term would not produce an infinite number of universes in some multiverse ensemble. In general, since the Einstein field equations in both situations are not well-posed, we further conclude that the existence of a multiverse via the stochastic eternal inflation mechanism considered in this paper is still very much an open question that will require much deeper investigation.

Construction of nonsingular pre-big-bang and ekpyrotic cosmologies and the resulting density perturbations

NASA Astrophysics Data System (ADS)

Tsujikawa, Shinji; Brandenberger, Robert; Finelli, Fabio

2002-10-01

We consider the construction of nonsingular pre-big-bang and ekpyrotic type cosmological models realized by the addition to the action of specific higher-order terms stemming from quantum corrections. We study models involving general relativity coupled to a single scalar field with a potential motivated by the ekpyrotic scenario. We find that the inclusion of the string loop and quantum correction terms in the string frame makes it possible to obtain solutions of the variational equations which are nonsingular and bouncing in the Einstein frame, even when a negative exponential potential is present, as is the case in the ekpyrotic scenario. This allows us to discuss the evolution of cosmological perturbations without the need to invoke matching conditions between two Einstein universes, one representing the contracting branch, the second the expanding branch. We analyze the spectra of perturbations produced during the bouncing phase and find that the spectrum of curvature fluctuations in the model proposed originally to implement the ekpyrotic scenario has a large blue tilt (nR=3). Except for instabilities introduced on small scales, the result agrees with what is obtained by imposing continuity of the induced metric and of the extrinsic curvature across a constant scalar field (up to k2 corrections equal to the constant energy density) matching surface between the contracting and the expanding Einstein universes. We also discuss nonsingular cosmological solutions obtained when a Gauss-Bonnet term with a coefficient suitably dependent on the scalar matter field is added to the action in the Einstein frame with a potential for the scalar field present. In this scenario, nonsingular solutions are found which start in an asymptotically flat state, undergo a period of superexponential inflation, and end with a graceful exit. The spectrum of fluctuations is also calculated in this case.

Complex quantum network geometries: Evolution and phase transitions

NASA Astrophysics Data System (ADS)

Bianconi, Ginestra; Rahmede, Christoph; Wu, Zhihao

2015-08-01

Networks are topological and geometric structures used to describe systems as different as the Internet, the brain, or the quantum structure of space-time. Here we define complex quantum network geometries, describing the underlying structure of growing simplicial 2-complexes, i.e., simplicial complexes formed by triangles. These networks are geometric networks with energies of the links that grow according to a nonequilibrium dynamics. The evolution in time of the geometric networks is a classical evolution describing a given path of a path integral defining the evolution of quantum network states. The quantum network states are characterized by quantum occupation numbers that can be mapped, respectively, to the nodes, links, and triangles incident to each link of the network. We call the geometric networks describing the evolution of quantum network states the quantum geometric networks. The quantum geometric networks have many properties common to complex networks, including small-world property, high clustering coefficient, high modularity, and scale-free degree distribution. Moreover, they can be distinguished between the Fermi-Dirac network and the Bose-Einstein network obeying, respectively, the Fermi-Dirac and Bose-Einstein statistics. We show that these networks can undergo structural phase transitions where the geometrical properties of the networks change drastically. Finally, we comment on the relation between quantum complex network geometries, spin networks, and triangulations.

Complex quantum network geometries: Evolution and phase transitions.

PubMed

Bianconi, Ginestra; Rahmede, Christoph; Wu, Zhihao

2015-08-01

Networks are topological and geometric structures used to describe systems as different as the Internet, the brain, or the quantum structure of space-time. Here we define complex quantum network geometries, describing the underlying structure of growing simplicial 2-complexes, i.e., simplicial complexes formed by triangles. These networks are geometric networks with energies of the links that grow according to a nonequilibrium dynamics. The evolution in time of the geometric networks is a classical evolution describing a given path of a path integral defining the evolution of quantum network states. The quantum network states are characterized by quantum occupation numbers that can be mapped, respectively, to the nodes, links, and triangles incident to each link of the network. We call the geometric networks describing the evolution of quantum network states the quantum geometric networks. The quantum geometric networks have many properties common to complex networks, including small-world property, high clustering coefficient, high modularity, and scale-free degree distribution. Moreover, they can be distinguished between the Fermi-Dirac network and the Bose-Einstein network obeying, respectively, the Fermi-Dirac and Bose-Einstein statistics. We show that these networks can undergo structural phase transitions where the geometrical properties of the networks change drastically. Finally, we comment on the relation between quantum complex network geometries, spin networks, and triangulations.

The extended Einstein-Maxwell-aether-axion model: Exact solutions for axionically controlled pp-wave aether modes

NASA Astrophysics Data System (ADS)

Balakin, Alexander B.

2018-03-01

The extended Einstein-Maxwell-aether-axion model describes internal interactions inside the system, which contains gravitational, electromagnetic fields, the dynamic unit vector field describing the velocity of an aether, and the pseudoscalar field associated with the axionic dark matter. The specific feature of this model is that the axion field controls the dynamics of the aether through the guiding functions incorporated into Jacobson’s constitutive tensor. Depending on the state of the axion field, these guiding functions can control and switch on or switch off the influence of acceleration, shear, vorticity and expansion of the aether flow on the state of physical system as a whole. We obtain new exact solutions, which possess the pp-wave symmetry, and indicate them by the term pp-wave aether modes in contrast to the pure pp-waves, which cannot propagate in this field conglomerate. These exact solutions describe a specific dynamic state of the pseudoscalar field, which corresponds to one of the minima of the axion potential and switches off the influence of shear and expansion of the aether flow; the model does not impose restrictions on Jacobson’s coupling constants and on the axion mass. Properties of these new exact solutions are discussed.

Quantum Mechanics of the Einstein-Hopf Model.

ERIC Educational Resources Information Center

Milonni, P. W.

1981-01-01

The Einstein-Hopf model for the thermodynamic equilibrium between the electromagnetic field and dipole oscillators is considered within the framework of quantum mechanics. Both the wave and particle aspects of the Einstein fluctuation formula are interpreted in terms of the fundamental absorption and emission processes. (Author/SK)

Einstein and the "Crucial" Experiment

ERIC Educational Resources Information Center

Holton, Gerald

1969-01-01

Examines the widespread view that it was the crucial Michelson-Morley experiment that led Einstein to formulate the special relativity theory. From Einstein's writings, evidence is presented that no such direct genetic connection exists. The author suggests that the historian of science must resist the experimenticist's fallacy of imposing a…

Laser refrigeration of hydrothermal nanocrystals in physiological media.

PubMed

Roder, Paden B; Smith, Bennett E; Zhou, Xuezhe; Crane, Matthew J; Pauzauskie, Peter J

2015-12-08

Coherent laser radiation has enabled many scientific and technological breakthroughs including Bose-Einstein condensates, ultrafast spectroscopy, superresolution optical microscopy, photothermal therapy, and long-distance telecommunications. However, it has remained a challenge to refrigerate liquid media (including physiological buffers) during laser illumination due to significant background solvent absorption and the rapid (∼ ps) nonradiative vibrational relaxation of molecular electronic excited states. Here we demonstrate that single-beam laser trapping can be used to induce and quantify the local refrigeration of physiological media by >10 °C following the emission of photoluminescence from upconverting yttrium lithium fluoride (YLF) nanocrystals. A simple, low-cost hydrothermal approach is used to synthesize polycrystalline particles with sizes ranging from <200 nm to >1 μm. A tunable, near-infrared continuous-wave laser is used to optically trap individual YLF crystals with an irradiance on the order of 1 MW/cm(2). Heat is transported out of the crystal lattice (across the solid-liquid interface) by anti-Stokes (blue-shifted) photons following upconversion of Yb(3+) electronic excited states mediated by the absorption of optical phonons. Temperatures are quantified through analysis of the cold Brownian dynamics of individual nanocrystals in an inhomogeneous temperature field via forward light scattering in the back focal plane. The cold Brownian motion (CBM) analysis of individual YLF crystals indicates local cooling by >21 °C below ambient conditions in D2O, suggesting a range of potential future applications including single-molecule biophysics and integrated photonic, electronic, and microfluidic devices.

Paul Ehrenfest, Niels Bohr, and Albert Einstein: Colleagues and Friends

NASA Astrophysics Data System (ADS)

Klein, Martin J.

2010-09-01

In May 1918 Paul Ehrenfest received a monograph from Niels Bohr in which Bohr had used Ehrenfest's adiabatic principle as an essential assumption for understanding atomic structure. Ehrenfest responded by inviting Bohr, whom he had never met, to give a talk at a meeting in Leiden in late April 1919, which Bohr accepted; he lived with Ehrenfest, his mathematician wife Tatyana, and their young family for two weeks. Albert Einstein was unable to attend this meeting, but in October 1919 he visited his old friend Ehrenfest and his family in Leiden, where Ehrenfest told him how much he had enjoyed and profited from Bohr's visit. Einstein first met Bohr when Bohr gave a lecture in Berlin at the end of April 1920, and the two immediately proclaimed unbounded admiration for each other as physicists and as human beings. Ehrenfest hoped that he and they would meet at the Third Solvay Conference in Brussels in early April 1921, but his hope was unfulfilled. Einstein, the only physicist from Germany who was invited to it in this bitter postwar atmosphere, decided instead to accompany Chaim Weizmann on a trip to the United States to help raise money for the new Hebrew University in Jerusalem. Bohr became so overworked with the planning and construction of his new Institute for Theoretical Physics in Copenhagen that he could only draft the first part of his Solvay report and ask Ehrenfest to present it, which Ehrenfest agreed to do following the presentation of his own report. After recovering his strength, Bohr invited Ehrenfest to give a lecture in Copenhagen that fall, and Ehrenfest, battling his deep-seated self-doubts, spent three weeks in Copenhagen in December 1921 accompanied by his daughter Tanya and her future husband, the two Ehrenfests staying with the Bohrs in their apartment in Bohr's new Institute for Theoretical Physics. Immediately after leaving Copenhagen, Ehrenfest wrote to Einstein, telling him once again that Bohr was a prodigious physicist, and again expressing the hope that he soon would see both of them in Leiden.

Numerical Relativity

NASA Technical Reports Server (NTRS)

Baker, John G.

2009-01-01

Recent advances in numerical relativity have fueled an explosion of progress in understanding the predictions of Einstein's theory of gravity, General Relativity, for the strong field dynamics, the gravitational radiation wave forms, and consequently the state of the remnant produced from the merger of compact binary objects. I will review recent results from the field, focusing on mergers of two black holes.

Displacements Of Brownian Particles In Terms Of Marian Von Smoluchowski's Heuristic Model

ERIC Educational Resources Information Center

Klein, Hermann; Woermann, Dietrich

2005-01-01

Albert Einstein's theory of the Brownian motion, Marian von Smoluchowski's heuristic model, and Perrin's experimental results helped to bring the concept of molecules from a state of being a useful hypothesis in chemistry to objects existing in reality. Central to the theory of Brownian motion is the relation between mean particle displacement and…

Einstein as a Missionary of Science

ERIC Educational Resources Information Center

Renn, Jürgen

2013-01-01

The paper reviews Einstein's engagement as a mediator and popularizer of science. It discusses the formative role of popular scientific literature for the young Einstein, showing that not only his broad scientific outlook but also his internationalist political views were shaped by these readings. Then, on the basis of recent detailed…

Einstein for Everyone

ScienceCinema

Piccioni, Robert

2018-04-25

Young Einstein was a rebel who seemed doomed to fail. How did he overcome rejection to become the most famous scientist in history? We will discuss and explain all his theories in plain English and without math, and we will discover how Einstein's achievements impact our lives through DVDs, GPS, iPods, computers and green energy.

Einstein for Everyone

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

Piccioni, Robert

2010-10-05

Young Einstein was a rebel who seemed doomed to fail. How did he overcome rejection to become the most famous scientist in history? We will discuss and explain all his theories in plain English and without math, and we will discover how Einstein's achievements impact our lives through DVDs, GPS, iPods, computers and green energy.

Einsteins Spuren in den Archiven der Wissenschaft: Physikgeschichte

NASA Astrophysics Data System (ADS)

Marx, Werner

2005-07-01

Die Erwähnungen und Zitierungen von Einsteins Arbeiten dokumentieren lediglich den quantifizierbaren Anteil von Einsteins Beitrag zur Physik. Gleichwohl belegen sie die außergewöhnliche Resonanz und Langzeitwirkung seiner Arbeiten. Die Häufigkeit der Zitierungen entspricht nicht der allgemeinen Einschätzung ihrer Bedeutung. Insbesondere die Pionierarbeiten werden inzwischen als bekannt vorausgesetzt und nicht mehr explizit zitiert. Interessanterweise ist seine nach 1945 meist zitierte Arbeit nicht eine der Pionierarbeiten zur Quantenphysik oder Relativitätstheorie, sondern jene aus dem Jahr 1935 zum berühmten Einstein-Podolsky-Rosen-Paradoxon.

Einstein: A Historical Perspective

NASA Astrophysics Data System (ADS)

Kormos-Buchwald, Diana

2015-04-01

In late 1915, Albert Einstein (1879-1955) completed as series of papers on a generalized theory of gravitation that were to constitute a major conceptual change in the history of modern physics and the crowning achievement of his scientific career. But this accomplishment came after a decade of intense intellectual struggle and was received with muted enthusiasm. Einstein's previously unpublished writings and massive correspondence, edited by the Einstein Papers Project, provide vivid insights into the historical, personal, and scientific context of the formulation, completion, and reception of GR during the first decades of the 20th century.

Two types of phase diagrams for two-species Bose-Einstein condensates and the combined effect of the parameters

NASA Astrophysics Data System (ADS)

Li, Z. B.; Liu, Y. M.; Yao, D. X.; Bao, C. G.

2017-07-01

Under the Thomas-Fermi approximation, an approach is proposed to solve the coupled Gross-Pitaevskii equations (CGP) for the two-species Bose-Einstein condensate analytically. The essence of this approach is to find out the building blocks to build the solution. By introducing the weighted strengths, relatively simpler analytical solutions have been obtained. A number of formulae have been deduced to relate the parameters when the system is experimentally tuned at various status. These formulae demonstrate the combined effect of the parameters, and are useful for the evaluation of their magnitudes. The whole parameter space is divided into zones, where each supports a specific phase. All the boundaries separating these zones have analytical expressions. Based on the division, the phase diagrams against any set of parameters can be plotted. In addition, by introducing a model for the asymmetric states, the total energies of the lowest symmetric and asymmetric states have been compared. Thereby, in which case the former will be replaced by the latter has been evaluated. The CGP can be written in a matrix form. For repulsive inter-species interaction V AB , when the parameters vary and cross over the singular point of the matrix, a specific state transition will happen and the total energy of the lowest symmetric state will increase remarkably. This provides an excellent opportunity for the lowest asymmetric state to emerge as the ground state. For attractive V AB , when the parameters tend to a singular point, the system will tend to collapse. The effects caused by the singular points have been particularly studied.

Non-naturally reductive Einstein metrics on exceptional Lie groups

NASA Astrophysics Data System (ADS)

Chrysikos, Ioannis; Sakane, Yusuke

2017-06-01

Given an exceptional compact simple Lie group G we describe new left-invariant Einstein metrics which are not naturally reductive. In particular, we consider fibrations of G over flag manifolds with a certain kind of isotropy representation and we construct the Einstein equation with respect to the induced left-invariant metrics. Then we apply a technique based on Gröbner bases and classify the real solutions of the associated algebraic systems. For the Lie group G2 we obtain the first known example of a left-invariant Einstein metric, which is not naturally reductive. Moreover, for the Lie groups E7 and E8, we conclude that there exist non-isometric non-naturally reductive Einstein metrics, which are Ad(K) -invariant by different Lie subgroups K.

How History Helped Einstein in Special Relativity

NASA Astrophysics Data System (ADS)

Martinez, Alberto

2013-04-01

I will discuss how the German intellectual movement known as ``critical history'' motivated several physicists in the late 1900s to radically analyze the fundamental principles of mechanics, leading eventually to Einstein's special theory of relativity. Eugen Karl Dühring, Johann Bernhard Stallo, Ludwig Lange, and Ernst Mach wrote critical histories of mechanics, some of which emphasized notions of relativity and observation, in opposition to old metaphysical concepts that seemed to infect the foundations of physics. This strand of critical history included the ``genetic method'' of analyzing how concepts develop over time, in our minds, by way of ordinary experiences, which by 1904 was young Albert Einstein's favorite approach for examining fundamental notions. Thus I will discuss how history contributed in Einstein's path to relativity, as well as comment more generally on Einstein's views on history.

Einstein Critical-Slowing-Down is Siegel CyberWar Denial-of-Access Queuing/Pinning/ Jamming/Aikido Via Siegel DIGIT-Physics BEC ``Intersection''-BECOME-UNION Barabasi Network/GRAPH-Physics BEC: Strutt/Rayleigh-Siegel Percolation GLOBALITY-to-LOCALITY Phase-Transition Critical-Phenomenon

NASA Astrophysics Data System (ADS)

Buick, Otto; Falcon, Pat; Alexander, G.; Siegel, Edward Carl-Ludwig

2013-03-01

Einstein[Dover(03)] critical-slowing-down(CSD)[Pais, Subtle in The Lord; Life & Sci. of Albert Einstein(81)] is Siegel CyberWar denial-of-access(DOA) operations-research queuing theory/pinning/jamming/.../Read [Aikido, Aikibojitsu & Natural-Law(90)]/Aikido(!!!) phase-transition critical-phenomenon via Siegel DIGIT-Physics (Newcomb[Am.J.Math. 4,39(1881)]-{Planck[(1901)]-Einstein[(1905)])-Poincare[Calcul Probabilités(12)-p.313]-Weyl [Goett.Nachr.(14); Math.Ann.77,313 (16)]-{Bose[(24)-Einstein[(25)]-Fermi[(27)]-Dirac[(1927)]}-``Benford''[Proc.Am.Phil.Soc. 78,4,551 (38)]-Kac[Maths.Stat.-Reasoning(55)]-Raimi[Sci.Am. 221,109 (69)...]-Jech[preprint, PSU(95)]-Hill[Proc.AMS 123,3,887(95)]-Browne[NYT(8/98)]-Antonoff-Smith-Siegel[AMS Joint-Mtg.,S.-D.(02)] algebraic-inversion to yield ONLY BOSE-EINSTEIN QUANTUM-statistics (BEQS) with ZERO-digit Bose-Einstein CONDENSATION(BEC) ``INTERSECTION''-BECOME-UNION to Barabasi[PRL 876,5632(01); Rev.Mod.Phys.74,47(02)...] Network /Net/GRAPH(!!!)-physics BEC: Strutt/Rayleigh(1881)-Polya(21)-``Anderson''(58)-Siegel[J.Non-crystalline-Sol.40,453(80)

Steady States, Fluctuation-Dissipation Theorems and Homogenization for Reversible Diffusions in a Random Environment

NASA Astrophysics Data System (ADS)

Mathieu, P.; Piatnitski, A.

2018-04-01

Prolongating our previous paper on the Einstein relation, we study the motion of a particle diffusing in a random reversible environment when subject to a small external forcing. In order to describe the long time behavior of the particle, we introduce the notions of steady state and weak steady state. We establish the continuity of weak steady states for an ergodic and uniformly elliptic environment. When the environment has finite range of dependence, we prove the existence of the steady state and weak steady state and compute its derivative at a vanishing force. Thus we obtain a complete `fluctuation-dissipation Theorem' in this context as well as the continuity of the effective variance.

Condensate statistics in interacting and ideal dilute bose gases

PubMed

Kocharovsky; Kocharovsky; Scully

2000-03-13

We obtain analytical formulas for the statistics, in particular, for the characteristic function and all cumulants, of the Bose-Einstein condensate in dilute weakly interacting and ideal equilibrium gases in the canonical ensemble via the particle-number-conserving operator formalism of Girardeau and Arnowitt. We prove that the ground-state occupation statistics is not Gaussian even in the thermodynamic limit. We calculate the effect of Bogoliubov coupling on suppression of ground-state occupation fluctuations and show that they are governed by a pair-correlation, squeezing mechanism.

Horizon structure of rotating Einstein-Born-Infeld black holes and shadow

NASA Astrophysics Data System (ADS)

Atamurotov, Farruh; Ghosh, Sushant G.; Ahmedov, Bobomurat

2016-05-01

We investigate the horizon structure of the rotating Einstein-Born-Infeld solution which goes over to the Einstein-Maxwell's Kerr-Newman solution as the Born-Infeld parameter goes to infinity (β → ∞). We find that for a given β , mass M, and charge Q, there exist a critical spinning parameter aE and rHE, which corresponds to an extremal Einstein-Born-Infeld black hole with degenerate horizons, and aE decreases and rHE increases with increase of the Born-Infeld parameter β , while a

Formation, stability and crystal structure of mullite-type Al{sub 6−x}B{sub x}O{sub 9}

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

Hoffmann, K., E-mail: Kristin.Hoffmann@uni-bremen.de; Institut für Anorganische Chemie und Kristallographie, FB02, Leobener Straße/NW2, Universität Bremen, D-28359 Bremen; Hooper, T.J.N.

2016-11-15

Mullite-type Al{sub 6−x}B{sub x}O{sub 9} compounds were studied by means of powder diffraction and spectroscopic methods. The backbones of this structure are chains of edge-connected AlO{sub 6} octahedra crosslinked by AlO- and BO-polyhedra. Rietveld refinements show that the a and b lattice parameters can be well resolved, thus representing an orthorhombic metric. A continuous decrease of the lattice parameters most pronounced in c-direction indicates a solid solution for Al{sub 6−x}B{sub x}O{sub 9} with 1.09≤x≤2. A preference of boron in 3-fold coordination is confirmed by {sup 11}B MAS NMR spectroscopy and Fourier calculations based on neutron diffraction data collected at 4more » K. Distance Least Squares modeling was performed to simulate a local geometry avoiding long B-O distances linking two octahedral chains by planar BO{sub 3} groups yielding split positions for the oxygen atoms and a strong distortion in the octahedral chains. The lattice thermal expansion was calculated using the Grüneisen first-order equation of state Debye-Einstein-Anharmonicity model. - Graphical abstract: Local distortion induced by boron linking the octahedral chains. - Highlights: • Decreasing lattice parameters indicate a solid solution for Al{sub 6−x}B{sub x}O{sub 9} (1.09≤x≤2). • B-atoms induce a local distortion of neighboring AlO{sub 6} octahedra. • A preference of boron in BO{sub 3} coordination is confirmed by {sup 11}B MAS NMR spectroscopy. • An optimized structural model for Al{sub 6−x}B{sub x}O{sub 9} is presented.« less

Einstein-Langevin and Einstein-Fokker-Planck equations for Oppenheimer-Snyder gravitational collapse in a spacetime with conformal vacuum fluctuations

NASA Astrophysics Data System (ADS)

Miller, Steven David

1999-10-01

A consistent extension of the Oppenheimer-Snyder gravitational collapse formalism is presented which incorporates stochastic, conformal, vacuum fluctuations of the metric tensor. This results in a tractable approach to studying the possible effects of vacuum fluctuations on collapse and singularity formation. The motivation here, is that it is known that coupling stochastic noise to a classical field theory can lead to workable methodologies that accommodate or reproduce many aspects of quantum theory, turbulence or structure formation. The effect of statistically averaging over the metric fluctuations gives the appearance of a deterministic Riemannian structure, with an induced non-vanishing cosmological constant arising from the nonlinearity. The Oppenheimer-Snyder collapse of a perfect fluid or dust star in the fluctuating or `turbulent' spacetime, is reformulated in terms of nonlinear Einstein-Langevin field equations, with an additional noise source in the energy-momentum tensor. The smooth deterministic worldlines of collapsing matter within the classical Oppenheimer-Snyder model, now become nonlinear Brownian motions due to the backreaction induced by vacuum fluctuations. As the star collapses, the matter worldlines become increasingly randomized since the backreaction coupling to the vacuum fluctuations is nonlinear; the input assumptions of the Hawking-Penrose singularity theorems should then be violated. Solving the nonlinear Einstein-Langevin field equation for collapse - via the Ito interpretation - gives a singularity-free solution, which is equivalent to the original Oppenheimer solution but with higher-order stochastic corrections; the original singular solution is recovered in the limit of zero vacuum fluctuations. The `geometro-hydrodynamics' of noisy gravitational collapse, were also translated into an equivalent mathematical formulation in terms of nonlinear Einstein-Fokker-Planck (EFP) continuity equations with respect to comoving coordinates: these describe the collapse as a conserved flow of probability. A solution was found in the dilute limit of weak fluctuations where the EFP equation is linearized. There is zero probability that the star collapses to a singular state in the presence of background vacuum fluctuations, but the singularity returns with unit probability when the fluctuations are reduced to zero. Finally, an EFP equation was considered with respect to standard exterior coordinates. Using the thermal Brownian motion paradigm, an exact stationary or equilibrium solution was found in the infinite standard time relaxation limit. The solution gives the conditions required for the final collapsed object (a black hole) to be in thermal equilibrium with the background vacuum fluctuations. From this solution, one recovers the Hawking temperature without using field theory. The stationary solution then seems to correspond to a black hole in thermal equilibrium with a fluctuating conformal scalar field; or the Hawking-Hartle state.

From the Classroom to Washington: Einsteins on Education Reform

ERIC Educational Resources Information Center

Hughes, Kent H., Ed.; Byers, Elizabeth A., Ed.

2010-01-01

The Woodrow Wilson International Center for Scholars was delighted to host a group of current and former Albert Einstein Distinguished Educator Fellows as they celebrated the 20th anniversary of the fellowship program. Outstanding math and science teachers in America's K-12 schools, the Einstein Fellows spend a year (or sometimes two) working on…

What Einstein Can Teach Us about Education

ERIC Educational Resources Information Center

Hayes, Denis

2007-01-01

People are more likely to associate Einstein with complex scientific theories and mathematical calculations than with education theory. In fact, Einstein's own experiences of schooling and his reflections on the meaning of life and the significance of education are profound and oddly relevant to the situation that pertains in England today. It is…

Compliance of the Stokes-Einstein model and breakdown of the Stokes-Einstein-Debye model for a urea-based supramolecular polymer of high viscosity.

PubMed

Świergiel, Jolanta; Bouteiller, Laurent; Jadżyn, Jan

2014-11-14

Impedance spectroscopy was used for the study of the static and dynamic behavior of the electrical conductivity of a hydrogen-bonded supramolecular polymer of high viscosity. The experimental data are discussed in the frame of the Stokes-Einstein and Stokes-Einstein-Debye models. It was found that the translational movement of the ions is due to normal Brownian diffusion, which was revealed by a fulfillment of Ohm's law by the electric current and a strictly exponential decay of the current after removing the electric stimulus. The dependence of the dc conductivity on the viscosity of the medium fulfills the Stokes-Einstein model quite well. An extension of the model, by including in it the conductivity relaxation time, is proposed in this paper. A breakdown of the Stokes-Einstein-Debye model is revealed by the relations of the dipolar relaxation time to the viscosity and to the dc ionic conductivity. The importance of the C=O···H-N hydrogen bonds in that breakdown is discussed.

Derivation of Einstein-Cartan theory from general relativity

NASA Astrophysics Data System (ADS)

Petti, Richard

2015-04-01

General relativity cannot describe exchange of classical intrinsic angular momentum and orbital angular momentum. Einstein-Cartan theory fixes this problem in the least invasive way. In the late 20th century, the consensus view was that Einstein-Cartan theory requires inclusion of torsion without adequate justification, it has no empirical support (though it doesn't conflict with any known evidence), it solves no important problem, and it complicates gravitational theory with no compensating benefit. In 1986 the author published a derivation of Einstein-Cartan theory from general relativity, with no additional assumptions or parameters. Starting without torsion, Poincaré symmetry, classical or quantum spin, or spinors, it derives torsion and its relation to spin from a continuum limit of general relativistic solutions. The present work makes the case that this computation, combined with supporting arguments, constitutes a derivation of Einstein-Cartan theory from general relativity, not just a plausibility argument. This paper adds more and simpler explanations, more computational details, correction of a factor of 2, discussion of limitations of the derivation, and discussion of some areas of gravitational research where Einstein-Cartan theory is relevant.

Why did Einstein reject the November tensor in 1912-1913, only to come back to it in November 1915?

NASA Astrophysics Data System (ADS)

Weinstein, Galina

2018-05-01

The question of Einstein's rejection of the November tensor is re-examined in light of conflicting answers by several historians. I discuss these conflicting conjectures in view of three questions that should inform our thinking: Why did Einstein reject the November tensor in 1912, only to come back to it in 1915? Why was it hard for Einstein to recognize that the November tensor is a natural generalization of Newton's law of gravitation? Why did it take him three years to realize that the November tensor is not incompatible with Newton's law? I first briefly describe Einstein's work in the Zurich Notebook. I then discuss a number of interpretive conjectures formulated by historians and what may be inferred from them. Finally, I offer a new combined conjecture that answers the above questions.

Dark matter influence on black objects thermodynamics

NASA Astrophysics Data System (ADS)

Rogatko, Marek; Wojnar, Aneta

2018-05-01

Physical process version of the first law of black hole thermodynamics in Einstein-Maxwell dark matter gravity was derived. The dark matter sector is mimicked by the additional U(1)-gauge field coupled to the ordinary Maxwell one. By considering any cross section of the black hole event horizon to the future of the bifurcation surface, the equilibrium state version of the first law of black hole mechanics was achieved. The considerations were generalized to the case of Einstein-Yang-Mills dark matter gravity theory. The main conclusion is that the influence of dark matter is crucial in the formation process of black objects. This fact may constitute the explanation of the recent observations of the enormous mass of the super luminous quasars formed in a relatively short time after Big Bang. We also pay attention to the compact binaries thermodynamics, when dark matter sector enters the game.

Signifying quantum benchmarks for qubit teleportation and secure quantum communication using Einstein-Podolsky-Rosen steering inequalities

NASA Astrophysics Data System (ADS)

Reid, M. D.

2013-12-01

The demonstration of quantum teleportation of a photonic qubit from Alice to Bob usually relies on data conditioned on detection at Bob's location. I show that Bohm's Einstein-Podolsky-Rosen (EPR) paradox can be used to verify that the quantum benchmark for qubit teleportation has been reached, without postselection. This is possible for scenarios insensitive to losses at the generation station, and with efficiencies of ηB>1/3 for the teleportation process. The benchmark is obtained if it is shown that Bob can “steer” Alice's record of the qubit as stored by Charlie. EPR steering inequalities involving m measurement settings can also be used to confirm quantum teleportation, for efficiencies ηB>1/m, if one assumes trusted detectors for Charlie and Alice. Using proofs of monogamy, I show that two-setting EPR steering inequalities can signify secure teleportation of the qubit state.

Relativistic Bose-Einstein condensates thin-shell wormholes

NASA Astrophysics Data System (ADS)

Richarte, M. G.; Salako, I. G.; Graça, J. P. Morais; Moradpour, H.; Övgün, Ali

2017-10-01

We construct traversable thin-shell wormholes which are asymptotically Ads/dS applying the cut and paste procedure for the case of an acoustic metric created by a relativistic Bose-Einstein condensate. We examine several definitions of the flare-out condition along with the violation or not of the energy conditions for such relativistic geometries. Under reasonable assumptions about the equation of state of the matter located at the shell, we concentrate on the mechanical stability of wormholes under radial perturbation preserving the original spherical symmetry. To do so, we consider linearized perturbations around static solutions. We obtain that dS acoustic wormholes remain stable under radial perturbations as long as they have small radius; such wormholes with finite radius do not violate the strong/null energy condition. Besides, we show that stable Ads wormhole satisfy some of the energy conditions whereas unstable Ads wormhole with large radii violate them.

Sensing spontaneous collapse and decoherence with interfering Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Schrinski, Björn; Hornberger, Klaus; Nimmrichter, Stefan

2017-12-01

We study how matter-wave interferometry with Bose-Einstein condensates is affected by hypothetical collapse models and by environmental decoherence processes. Motivated by recent atom fountain experiments with macroscopic arm separations, we focus on the observable signatures of first-order and higher-order coherence for different two-mode superposition states, and on their scaling with particle number. This can be used not only to assess the impact of environmental decoherence on many-body coherence, but also to quantify the extent to which macrorealistic collapse models are ruled out by such experiments. We find that interference fringes of phase-coherently split condensates are most strongly affected by decoherence, whereas the quantum signatures of independent interfering condensates are more immune against macrorealistic collapse. A many-body enhanced decoherence effect beyond the level of a single atom can be probed if higher-order correlations are resolved in the interferogram.

Spatially distributed multipartite entanglement enables EPR steering of atomic clouds.

PubMed

Kunkel, Philipp; Prüfer, Maximilian; Strobel, Helmut; Linnemann, Daniel; Frölian, Anika; Gasenzer, Thomas; Gärttner, Martin; Oberthaler, Markus K

2018-04-27

A key resource for distributed quantum-enhanced protocols is entanglement between spatially separated modes. However, the robust generation and detection of entanglement between spatially separated regions of an ultracold atomic system remain a challenge. We used spin mixing in a tightly confined Bose-Einstein condensate to generate an entangled state of indistinguishable particles in a single spatial mode. We show experimentally that this entanglement can be spatially distributed by self-similar expansion of the atomic cloud. We used spatially resolved spin read-out to reveal a particularly strong form of quantum correlations known as Einstein-Podolsky-Rosen (EPR) steering between distinct parts of the expanded cloud. Based on the strength of EPR steering, we constructed a witness, which confirmed genuine 5-partite entanglement. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Bogoliubov theory and Lee-Huang-Yang corrections in spin-1 and spin-2 Bose-Einstein condensates in the presence of the quadratic Zeeman effect

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

Uchino, Shun; Kobayashi, Michikazu; Ueda, Masahito

2010-06-15

We develop Bogoliubov theory of spin-1 and spin-2 Bose-Einstein condensates (BECs) in the presence of a quadratic Zeeman effect, and derive the Lee-Huang-Yang (LHY) corrections to the ground-state energy, pressure, sound velocity, and quantum depletion. We investigate all the phases of spin-1 and spin-2 BECs that can be realized experimentally. We also examine the stability of each phase against quantum fluctuations and the quadratic Zeeman effect. Furthermore, we discuss a relationship between the number of symmetry generators that are spontaneously broken and that of Nambu-Goldstone (NG) modes. It is found that in the spin-2 nematic phase there are special Bogoliubovmore » modes that have gapless linear dispersion relations but do not belong to the NG modes.« less

Experimental Observation of One-Dimensional Superradiance Lattices in Ultracold Atoms

NASA Astrophysics Data System (ADS)

Chen, Liangchao; Wang, Pengjun; Meng, Zengming; Huang, Lianghui; Cai, Han; Wang, Da-Wei; Zhu, Shi-Yao; Zhang, Jing

2018-05-01

We measure the superradiant emission in a one-dimensional (1D) superradiance lattice (SL) in ultracold atoms. Resonantly excited to a superradiant state, the atoms are further coupled to other collectively excited states, which form a 1D SL. The directional emission of one of the superradiant excited states in the 1D SL is measured. The emission spectra depend on the band structure, which can be controlled by the frequency and intensity of the coupling laser fields. This work provides a platform for investigating the collective Lamb shift of resonantly excited superradiant states in Bose-Einstein condensates and paves the way for realizing higher dimensional superradiance lattices.

Different operational meanings of continuous variable Gaussian entanglement criteria and Bell inequalities

NASA Astrophysics Data System (ADS)

Buono, D.; Nocerino, G.; Solimeno, S.; Porzio, A.

2014-07-01

Entanglement, one of the most intriguing aspects of quantum mechanics, marks itself into different features of quantum states. For this reason different criteria can be used for verifying entanglement. In this paper we review some of the entanglement criteria casted for continuous variable states and link them to peculiar aspects of the original debate on the famous Einstein-Podolsky-Rosen (EPR) paradox. We also provide a useful expression for valuating Bell-type non-locality on Gaussian states. We also present the experimental measurement of a particular realization of the Bell operator over continuous variable entangled states produced by a sub-threshold type-II optical parametric oscillators (OPOs).

Quantum-Enhanced Sensing Based on Time Reversal of Nonlinear Dynamics.

PubMed

Linnemann, D; Strobel, H; Muessel, W; Schulz, J; Lewis-Swan, R J; Kheruntsyan, K V; Oberthaler, M K

2016-07-01

We experimentally demonstrate a nonlinear detection scheme exploiting time-reversal dynamics that disentangles continuous variable entangled states for feasible readout. Spin-exchange dynamics of Bose-Einstein condensates is used as the nonlinear mechanism which not only generates entangled states but can also be time reversed by controlled phase imprinting. For demonstration of a quantum-enhanced measurement we construct an active atom SU(1,1) interferometer, where entangled state preparation and nonlinear readout both consist of parametric amplification. This scheme is capable of exhausting the quantum resource by detecting solely mean atom numbers. Controlled nonlinear transformations widen the spectrum of useful entangled states for applied quantum technologies.

Anisotropic Invariance and the Distribution of Quantum Correlations.

PubMed

Cheng, Shuming; Hall, Michael J W

2017-01-06

We report the discovery of two new invariants for three-qubit states which, similarly to the three-tangle, are invariant under local unitary transformations and permutations of the parties. These quantities have a direct interpretation in terms of the anisotropy of pairwise spin correlations. Applications include a universal ordering of pairwise quantum correlation measures for pure three-qubit states; trade-off relations for anisotropy, three-tangle and Bell nonlocality; strong monogamy relations for Bell inequalities, Einstein-Podolsky-Rosen steering inequalities, geometric discord and fidelity of remote state preparation (including results for arbitrary three-party states); and a statistical and reference-frame-independent form of quantum secret sharing.

Anisotropic Invariance and the Distribution of Quantum Correlations

NASA Astrophysics Data System (ADS)

Cheng, Shuming; Hall, Michael J. W.

2017-01-01

We report the discovery of two new invariants for three-qubit states which, similarly to the three-tangle, are invariant under local unitary transformations and permutations of the parties. These quantities have a direct interpretation in terms of the anisotropy of pairwise spin correlations. Applications include a universal ordering of pairwise quantum correlation measures for pure three-qubit states; trade-off relations for anisotropy, three-tangle and Bell nonlocality; strong monogamy relations for Bell inequalities, Einstein-Podolsky-Rosen steering inequalities, geometric discord and fidelity of remote state preparation (including results for arbitrary three-party states); and a statistical and reference-frame-independent form of quantum secret sharing.

Hidden Symmetries of Euclideanised Kerr-NUT-(A)dS Metrics in Certain Scaling Limits

NASA Astrophysics Data System (ADS)

Visinescu, Mihai; Vîlcu, Eduard

2012-08-01

The hidden symmetries of higher dimensional Kerr-NUT-(A)dS metrics are investigated. In certain scaling limits these metrics are related to the Einstein-Sasaki ones. The complete set of Killing-Yano tensors of the Einstein-Sasaki spaces are presented. For this purpose the Killing forms of the Calabi-Yau cone over the Einstein-Sasaki manifold are constructed. Two new Killing forms on Einstein-Sasaki manifolds are identified associated with the complex volume form of the cone manifolds. Finally the Killing forms on mixed 3-Sasaki manifolds are briefly described.

All ASD complex and real 4-dimensional Einstein spaces with Λ≠0 admitting a nonnull Killing vector

NASA Astrophysics Data System (ADS)

Chudecki, Adam

2016-12-01

Anti-self-dual (ASD) 4-dimensional complex Einstein spaces with nonzero cosmological constant Λ equipped with a nonnull Killing vector are considered. It is shown that any conformally nonflat metric of such spaces can be always brought to a special form and the Einstein field equations can be reduced to the Boyer-Finley-Plebański equation (Toda field equation). Some alternative forms of the metric are discussed. All possible real slices (neutral, Euclidean and Lorentzian) of ASD complex Einstein spaces with Λ≠0 admitting a nonnull Killing vector are found.

Coordinated garbage collection for raid array of solid state disks

DOEpatents

Dillow, David A; Ki, Youngjae; Oral, Hakki S; Shipman, Galen M; Wang, Feiyi

2014-04-29

An optimized redundant array of solid state devices may include an array of one or more optimized solid-state devices and a controller coupled to the solid-state devices for managing the solid-state devices. The controller may be configured to globally coordinate the garbage collection activities of each of said optimized solid-state devices, for instance, to minimize the degraded performance time and increase the optimal performance time of the entire array of devices.

From Solvent-Free to Dilute Electrolytes: Essential Components for a Continuum Theory.

PubMed

Gavish, Nir; Elad, Doron; Yochelis, Arik

2018-01-04

The increasing number of experimental observations on highly concentrated electrolytes and ionic liquids show qualitative features that are distinct from dilute or moderately concentrated electrolytes, such as self-assembly, multiple-time relaxation, and underscreening, which all impact the emergence of fluid/solid interfaces, and the transport in these systems. Because these phenomena are not captured by existing mean-field models of electrolytes, there is a paramount need for a continuum framework for highly concentrated electrolytes and ionic liquid mixtures. In this work, we present a self-consistent spatiotemporal framework for a ternary composition that comprises ions and solvent employing a free energy that consists of short- and long-range interactions, along with an energy dissipation mechanism obtained by Onsager's relations. We show that the model can describe multiple bulk and interfacial morphologies at steady-state. Thus, the dynamic processes in the emergence of distinct morphologies become equally as important as the interactions that are specified by the free energy. The model equations not only provide insights into transport mechanisms beyond the Stokes-Einstein-Smoluchowski relations but also enable qualitative recovery of three distinct regions in the full range of the nonmonotonic electrical screening length that has been recently observed in experiments in which organic solvent is used to dilute ionic liquids.

Ultrathin high band gap solar cells with improved efficiencies from the world's oldest photovoltaic material.

PubMed

Todorov, Teodor K; Singh, Saurabh; Bishop, Douglas M; Gunawan, Oki; Lee, Yun Seog; Gershon, Talia S; Brew, Kevin W; Antunez, Priscilla D; Haight, Richard

2017-09-25

Selenium was used in the first solid state solar cell in 1883 and gave early insights into the photoelectric effect that inspired Einstein's Nobel Prize work; however, the latest efficiency milestone of 5.0% was more than 30 years ago. The recent surge of interest towards high-band gap absorbers for tandem applications led us to reconsider this attractive 1.95 eV material. Here, we show completely redesigned selenium devices with improved back and front interfaces optimized through combinatorial studies and demonstrate record open-circuit voltage (V OC ) of 970 mV and efficiency of 6.5% under 1 Sun. In addition, Se devices are air-stable, non-toxic, and extremely simple to fabricate. The absorber layer is only 100 nm thick, and can be processed at 200 ˚C, allowing temperature compatibility with most bottom substrates or sub-cells. We analyze device limitations and find significant potential for further improvement making selenium an attractive high-band-gap absorber for multi-junction device applications.Wide band gap semiconductors are important for the development of tandem photovoltaics. By introducing buffer layers at the front and rear side of solar cells based on selenium; Todorov et al., reduce interface recombination losses to achieve photoconversion efficiencies of 6.5%.

X-ray spectral observations of clusters of galaxies undergoing merger events

NASA Astrophysics Data System (ADS)

Henriksen, Mark J.

1993-09-01

We have analyzed the HEAO 1 A2 observations of two clusters whose optical and X-ray isophotes are suggestive of merging subclusters, A119 and A754, and find evidence of nonisothermal X-ray emission from both clusters. The X-ray spectrum of both clusters, when fitted with a single isothermal model, shows residual soft X-ray emission. There is a statistically significant reduction in chi-squared (98 percent probability based on the F-test) when a second temperature component is added. If the asymmetric isophotes seen in the soft X-ray image are indicative of merging subclusters, then our analysis of the Einstein IPC spectra and Solid State Spectrometer observations of A754, which provide some spatial and spectral resolution, suggests that the two temperature components seen in the HEAO 1 A2 spectra are associated with gas trapped in the subcluster potential wells. The implied subcluster isothermal masses suggest that a more massive cluster is accreting a less massive companion in A754. The present observations cannot rule out the alternative possibility that the cooler gas is associated with the outer cluster atmosphere rather than individual subclusters, as appears to be the case for A119. Astro D observations will be necessary to distinguish between these two possibilities for both clusters.

Scattering amplitudes in $$\\mathcal{N}=2 $$ Maxwell-Einstein and Yang-Mills/Einstein supergravity

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

Chiodaroli, Marco; Gunaydin, Murat; Johansson, Henrik

We expose a double-copy structure in the scattering amplitudes of the generic Jordan family of N = 2 Maxwell-Einstein and Yang-Mills/Einstein supergravity theories in four and five dimensions. The Maxwell-Einstein supergravity amplitudes are obtained through the color/kinematics duality as a product of two gauge-theory factors; one originating from pure N = 2 super-Yang-Mills theory and the other from the dimensional reduction of a bosonic higher-dimensional pure Yang-Mills theory. We identify a specific symplectic frame in four dimensions for which the on-shell fields and amplitudes from the double-copy construction can be identified with the ones obtained from the supergravity Lagrangian andmore » Feynman-rule computations. The Yang-Mills/Einstein supergravity theories are obtained by gauging a compact subgroup of the isometry group of their Maxwell-Einstein counterparts. For the generic Jordan family this process is identified with the introduction of cubic scalar couplings on the bosonic gauge-theory side, which through the double copy are responsible for the non-abelian vector interactions in the supergravity theory. As a demonstration of the power of this structure, we present explicit computations at treelevel and one loop. Lastly, the double-copy construction allows us to obtain compact expressions for the supergravity superamplitudes, which are naturally organized as polynomials in the gauge coupling constant.« less

Scattering amplitudes in $$\\mathcal{N}=2 $$ Maxwell-Einstein and Yang-Mills/Einstein supergravity

DOE PAGES

Chiodaroli, Marco; Gunaydin, Murat; Johansson, Henrik; ...

2015-01-15

We expose a double-copy structure in the scattering amplitudes of the generic Jordan family of N = 2 Maxwell-Einstein and Yang-Mills/Einstein supergravity theories in four and five dimensions. The Maxwell-Einstein supergravity amplitudes are obtained through the color/kinematics duality as a product of two gauge-theory factors; one originating from pure N = 2 super-Yang-Mills theory and the other from the dimensional reduction of a bosonic higher-dimensional pure Yang-Mills theory. We identify a specific symplectic frame in four dimensions for which the on-shell fields and amplitudes from the double-copy construction can be identified with the ones obtained from the supergravity Lagrangian andmore » Feynman-rule computations. The Yang-Mills/Einstein supergravity theories are obtained by gauging a compact subgroup of the isometry group of their Maxwell-Einstein counterparts. For the generic Jordan family this process is identified with the introduction of cubic scalar couplings on the bosonic gauge-theory side, which through the double copy are responsible for the non-abelian vector interactions in the supergravity theory. As a demonstration of the power of this structure, we present explicit computations at treelevel and one loop. Lastly, the double-copy construction allows us to obtain compact expressions for the supergravity superamplitudes, which are naturally organized as polynomials in the gauge coupling constant.« less

Classical defects in higher-dimensional Einstein gravity coupled to nonlinear σ -models

NASA Astrophysics Data System (ADS)

Prasetyo, Ilham; Ramadhan, Handhika S.

2017-09-01

We construct solutions of higher-dimensional Einstein gravity coupled to nonlinear σ -model with cosmological constant. The σ -model can be perceived as exterior configuration of a spontaneously-broken SO(D-1) global higher-codimensional "monopole". Here we allow the kinetic term of the σ -model to be noncanonical; in particular we specifically study a quadratic-power-law type. This is some possible higher-dimensional generalization of the Bariola-Vilenkin (BV) solutions with k-global monopole studied recently. The solutions can be perceived as the exterior solution of a black hole swallowing up noncanonical global defects. Even in the absence of comological constant its surrounding spacetime is asymptotically non-flat; it suffers from deficit solid angle. We discuss the corresponding horizons. For Λ >0 in 4 d there can exist three extremal conditions (the cold, ultracold, and Nariai black holes), while in higher-than-four dimensions the extremal black hole is only Nariai. For Λ <0 we only have black hole solutions with one horizon, save for the 4 d case where there can exist two horizons. We give constraints on the mass and the symmetry-breaking scale for the existence of all the extremal cases. In addition, we also obtain factorized solutions, whose topology is the direct product of two-dimensional spaces of constant curvature (M_2, dS_2, or AdS_2) with (D-2)-sphere. We study all possible factorized channels.

Identifying time scales for violation/preservation of Stokes-Einstein relation in supercooled water

PubMed Central

Kawasaki, Takeshi; Kim, Kang

2017-01-01

The violation of the Stokes-Einstein (SE) relation D ~ (η/T)−1 between the shear viscosity η and the translational diffusion constant D at temperature T is of great importance for characterizing anomalous dynamics of supercooled water. Determining which time scales play key roles in the SE violation remains elusive without the measurement of η. We provide comprehensive simulation results of the dynamic properties involving η and D in the TIP4P/2005 supercooled water. This enabled the thorough identification of the appropriate time scales for the SE relation Dη/T. In particular, it is demonstrated that the temperature dependence of various time scales associated with structural relaxation, hydrogen bond breakage, stress relaxation, and dynamic heterogeneities can be definitely classified into only two classes. That is, we propose the generalized SE relations that exhibit “violation” or “preservation.” The classification depends on the examined time scales that are coupled or decoupled with the diffusion. On the basis of the classification, we explain the physical origins of the violation in terms of the increase in the plateau modulus and the nonexponentiality of stress relaxation. This implies that the mechanism of SE violation is attributed to the attained solidity upon supercooling, which is in accord with the growth of non-Gaussianity and spatially heterogeneous dynamics. PMID:28835918

Books on Einstein--Collectors' Delight

ERIC Educational Resources Information Center

Khoon, Koh Aik; Jalal, Azman; Abd-Shukor, R.; Yatim, Baharudin; Talib, Ibrahim Abu; Daud, Abdul Razak; Samat, Supian

2009-01-01

A survey of thirteen books on Einstein is presented. Its gives an idea on how much is written about the man and how frequent are the publications. The year 2005 saw the most publications. It is the centenary for the Miraculous Year. Interestingly some books can just sustain their readers' interest with just words. Einstein comes alive with the…

On the Classical Roots of the Einstein-Podolsky-Rosen Paradox

ERIC Educational Resources Information Center

Lando, A.; Bringuier, E.

2008-01-01

The 1935 debate opposing Einstein, Podolsky and Rosen to Bohr elicited so many comments and developments, both theoretical and experimental, until this day, that the main point at stake at that time can be overlooked by modern readers, especially students. This paper draws the reader's attention to the historical background of Einstein's paper and…

A Demonstration of Einstein's Equivalence of Gravity and Acceleration

ERIC Educational Resources Information Center

Newburgh, Ronald

2008-01-01

In 1907, Einstein described a "Gedankenexperiment" in which he showed that free fall in a gravitational field is indistinguishable from a body at rest in an elevator accelerated upwards in zero gravity. This paper describes an apparatus, which is simple to make and simple to operate, that acts as an observable footnote to Einstein's example. It…

When Art Meets Einstein

ERIC Educational Resources Information Center

Science Scope, 2006

2006-01-01

This article deals with a pale blue sculpture entitled "A New World View", as an homage to the most famous scientist in modern history, Albert Einstein. It has 32 bas-relief squares composed of glass and steel that represent one aspect of the life and legacy of Albert Einstein. Images of children's faces peer out from behind the glass squares,…

Detonation Velocity Calculations of Explosives with Slowly-Burning Constituents

NASA Astrophysics Data System (ADS)

Howard, W. Michael; Souers, P. Clark; Fried, Laurence E.

1997-07-01

The thermochemical code Equilbrium CHEETAH has been modified to allow partial reaction of constituents and partial flow of heat. Solid or liquid reactants are described by Einstein oscillators, whose temperatures can be changed to allow heat transfer. Hydroxy-terminated-poly-budadiene, mixed with RDX or HMX, does not react, as shown by the effect on the calculated detonation velocity. Aluminum and ammonium perchlorate in composites also do not react. Only partial heat flow also takes place in the unreacted materials. These results show that the usual assumption of total burn in a thermochemical code is probably incorrect, at least in the sonic reaction zone that drives the detonation velocity. A kinetic code would be the logical extension of this work.

Mass as a Form of Energy in a Simple Example

ERIC Educational Resources Information Center

Dib, Claudio

2013-01-01

A major consequence of special relativity, expressed in the relation E[subscript 0] = mc[superscript 2], is that the total energy content of an object at rest, including its thermal motion and binding energy among its constituents, is a measure of its inertia, i.e., its mass. This relation was first stated by Einstein. He showed that, in order to…

Butterfly Floquet Spectrum in Driven SU(2) Systems

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

Wang Jiao; Department of Physics, Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen 361005; Gong Jiangbin

2009-06-19

The Floquet spectrum of a class of driven SU(2) systems is shown to display a butterfly pattern with multifractal properties. The level crossing between Floquet states of the same parity or different parities is studied. The results are relevant to studies of fractal statistics, quantum chaos, coherent destruction of tunneling, and the validity of mean-field descriptions of Bose-Einstein condensates.

Parametric instabilities in resonantly-driven Bose–Einstein condensates

NASA Astrophysics Data System (ADS)

Lellouch, S.; Goldman, N.

2018-04-01

Shaking optical lattices in a resonant manner offers an efficient and versatile method to devise artificial gauge fields and topological band structures for ultracold atomic gases. This was recently demonstrated through the experimental realization of the Harper–Hofstadter model, which combined optical superlattices and resonant time-modulations. Adding inter-particle interactions to these engineered band systems is expected to lead to strongly-correlated states with topological features, such as fractional Chern insulators. However, the interplay between interactions and external time-periodic drives typically triggers violent instabilities and uncontrollable heating, hence potentially ruling out the possibility of accessing such intriguing states of matter in experiments. In this work, we study the early-stage parametric instabilities that occur in systems of resonantly-driven Bose–Einstein condensates in optical lattices. We apply and extend an approach based on Bogoliubov theory (Lellouch et al 2017 Phys. Rev. X 7 021015) to a variety of resonantly-driven band models, from a simple shaken Wannier–Stark ladder to the more intriguing driven-induced Harper–Hofstadter model. In particular, we provide ab initio numerical and analytical predictions for the stability properties of these topical models. This work sheds light on general features that could guide current experiments to stable regimes of operation.

Efficient spectral computation of the stationary states of rotating Bose-Einstein condensates by preconditioned nonlinear conjugate gradient methods

NASA Astrophysics Data System (ADS)

Antoine, Xavier; Levitt, Antoine; Tang, Qinglin

2017-08-01

We propose a preconditioned nonlinear conjugate gradient method coupled with a spectral spatial discretization scheme for computing the ground states (GS) of rotating Bose-Einstein condensates (BEC), modeled by the Gross-Pitaevskii Equation (GPE). We first start by reviewing the classical gradient flow (also known as imaginary time (IMT)) method which considers the problem from the PDE standpoint, leading to numerically solve a dissipative equation. Based on this IMT equation, we analyze the forward Euler (FE), Crank-Nicolson (CN) and the classical backward Euler (BE) schemes for linear problems and recognize classical power iterations, allowing us to derive convergence rates. By considering the alternative point of view of minimization problems, we propose the preconditioned steepest descent (PSD) and conjugate gradient (PCG) methods for the GS computation of the GPE. We investigate the choice of the preconditioner, which plays a key role in the acceleration of the convergence process. The performance of the new algorithms is tested in 1D, 2D and 3D. We conclude that the PCG method outperforms all the previous methods, most particularly for 2D and 3D fast rotating BECs, while being simple to implement.

The Einstein-Vlasov System/Kinetic Theory.

PubMed

Andréasson, Håkan

2011-01-01

The main purpose of this article is to provide a guide to theorems on global properties of solutions to the Einstein-Vlasov system. This system couples Einstein's equations to a kinetic matter model. Kinetic theory has been an important field of research during several decades in which the main focus has been on non-relativistic and special relativistic physics, i.e., to model the dynamics of neutral gases, plasmas, and Newtonian self-gravitating systems. In 1990, Rendall and Rein initiated a mathematical study of the Einstein-Vlasov system. Since then many theorems on global properties of solutions to this system have been established. This paper gives introductions to kinetic theory in non-curved spacetimes and then the Einstein-Vlasov system is introduced. We believe that a good understanding of kinetic theory in non-curved spacetimes is fundamental to a good comprehension of kinetic theory in general relativity.

Covariant Conformal Decomposition of Einstein Equations

NASA Astrophysics Data System (ADS)

Gourgoulhon, E.; Novak, J.

It has been shown1,2 that the usual 3+1 form of Einstein's equations may be ill-posed. This result has been previously observed in numerical simulations3,4. We present a 3+1 type formalism inspired by these works to decompose Einstein's equations. This decomposition is motivated by the aim of stable numerical implementation and resolution of the equations. We introduce the conformal 3-``metric'' (scaled by the determinant of the usual 3-metric) which is a tensor density of weight -2/3. The Einstein equations are then derived in terms of this ``metric'', of the conformal extrinsic curvature and in terms of the associated derivative. We also introduce a flat 3-metric (the asymptotic metric for isolated systems) and the associated derivative. Finally, the generalized Dirac gauge (introduced by Smarr and York5) is used in this formalism and some examples of formulation of Einstein's equations are shown.

OH{sup +} in astrophysical media: state-to-state formation rates, Einstein coefficients and inelastic collision rates with He

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

Gómez-Carrasco, Susana; Godard, Benjamin; Lique, François

The rate constants required to model the OH{sup +} observations in different regions of the interstellar medium have been determined using state of the art quantum methods. First, state-to-state rate constants for the H{sub 2}(v = 0, J = 0, 1) + O{sup +}({sup 4} S) → H + OH{sup +}(X {sup 3}Σ{sup –}, v', N) reaction have been obtained using a quantum wave packet method. The calculations have been compared with time-independent results to assess the accuracy of reaction probabilities at collision energies of about 1 meV. The good agreement between the simulations and the existing experimental cross sectionsmore » in the 0.01-1 eV energy range shows the quality of the results. The calculated state-to-state rate constants have been fitted to an analytical form. Second, the Einstein coefficients of OH{sup +} have been obtained for all astronomically significant rovibrational bands involving the X {sup 3}Σ{sup –} and/or A {sup 3}Π electronic states. For this purpose, the potential energy curves and electric dipole transition moments for seven electronic states of OH{sup +} are calculated with ab initio methods at the highest level, including spin-orbit terms, and the rovibrational levels have been calculated including the empirical spin-rotation and spin-spin terms. Third, the state-to-state rate constants for inelastic collisions between He and OH{sup +}(X {sup 3}Σ{sup –}) have been calculated using a time-independent close coupling method on a new potential energy surface. All these rates have been implemented in detailed chemical and radiative transfer models. Applications of these models to various astronomical sources show that inelastic collisions dominate the excitation of the rotational levels of OH{sup +}. In the models considered, the excitation resulting from the chemical formation of OH{sup +} increases the line fluxes by about 10% or less depending on the density of the gas.« less

Investigating Einstein-Podolsky-Rosen steering of continuous-variable bipartite states by non-Gaussian pseudospin measurements

NASA Astrophysics Data System (ADS)

Xiang, Yu; Xu, Buqing; Mišta, Ladislav; Tufarelli, Tommaso; He, Qiongyi; Adesso, Gerardo

2017-10-01

Einstein-Podolsky-Rosen (EPR) steering is an asymmetric form of correlations which is intermediate between quantum entanglement and Bell nonlocality, and can be exploited as a resource for quantum communication with one untrusted party. In particular, steering of continuous-variable Gaussian states has been extensively studied theoretically and experimentally, as a fundamental manifestation of the EPR paradox. While most of these studies focused on quadrature measurements for steering detection, two recent works revealed that there exist Gaussian states which are only steerable by suitable non-Gaussian measurements. In this paper we perform a systematic investigation of EPR steering of bipartite Gaussian states by pseudospin measurements, complementing and extending previous findings. We first derive the density-matrix elements of two-mode squeezed thermal Gaussian states in the Fock basis, which may be of independent interest. We then use such a representation to investigate steering of these states as detected by a simple nonlinear criterion, based on second moments of the correlation matrix constructed from pseudospin operators. This analysis reveals previously unexplored regimes where non-Gaussian measurements are shown to be more effective than Gaussian ones to witness steering of Gaussian states in the presence of local noise. We further consider an alternative set of pseudospin observables, whose expectation value can be expressed more compactly in terms of Wigner functions for all two-mode Gaussian states. However, according to the adopted criterion, these observables are found to be always less sensitive than conventional Gaussian observables for steering detection. Finally, we investigate continuous-variable Werner states, which are non-Gaussian mixtures of Gaussian states, and find that pseudospin measurements are always more effective than Gaussian ones to reveal their steerability. Our results provide useful insights on the role of non-Gaussian measurements in characterizing quantum correlations of Gaussian and non-Gaussian states of continuous-variable quantum systems.

A review of lithium and non-lithium based solid state batteries

NASA Astrophysics Data System (ADS)

Kim, Joo Gon; Son, Byungrak; Mukherjee, Santanu; Schuppert, Nicholas; Bates, Alex; Kwon, Osung; Choi, Moon Jong; Chung, Hyun Yeol; Park, Sam

2015-05-01

Conventional lithium-ion liquid-electrolyte batteries are widely used in portable electronic equipment such as laptop computers, cell phones, and electric vehicles; however, they have several drawbacks, including expensive sealing agents and inherent hazards of fire and leakages. All solid state batteries utilize solid state electrolytes to overcome the safety issues of liquid electrolytes. Drawbacks for all-solid state lithium-ion batteries include high resistance at ambient temperatures and design intricacies. This paper is a comprehensive review of all aspects of solid state batteries: their design, the materials used, and a detailed literature review of various important advances made in research. The paper exhaustively studies lithium based solid state batteries, as they are the most prevalent, but also considers non-lithium based systems. Non-lithium based solid state batteries are attaining widespread commercial applications, as are also lithium based polymeric solid state electrolytes. Tabular representations and schematic diagrams are provided to underscore the unique characteristics of solid state batteries and their capacity to occupy a niche in the alternative energy sector.

The Uhlenbeck-Ford model: Exact virial coefficients and application as a reference system in fluid-phase free-energy calculations

NASA Astrophysics Data System (ADS)

Paula Leite, Rodolfo; Freitas, Rodrigo; Azevedo, Rodolfo; de Koning, Maurice

2016-11-01

The Uhlenbeck-Ford (UF) model was originally proposed for the theoretical study of imperfect gases, given that all its virial coefficients can be evaluated exactly, in principle. Here, in addition to computing the previously unknown coefficients B11 through B13, we assess its applicability as a reference system in fluid-phase free-energy calculations using molecular simulation techniques. Our results demonstrate that, although the UF model itself is too soft, appropriately scaled Uhlenbeck-Ford (sUF) models provide robust reference systems that allow accurate fluid-phase free-energy calculations without the need for an intermediate reference model. Indeed, in addition to the accuracy with which their free energies are known and their convenient scaling properties, the fluid is the only thermodynamically stable phase for a wide range of sUF models. This set of favorable properties may potentially put the sUF fluid-phase reference systems on par with the standard role that harmonic and Einstein solids play as reference systems for solid-phase free-energy calculations.

Genomic Basis of Prostate Cancer Health Disparity Among African American Men

DTIC Science & Technology

2015-10-01

Harry Ostrer, M.D. RECIPIENT: Albert Einstein College of Medicine Bronx, NY 10461 REPORT DATE: October 2015 TYPE OF REPORT: Final report...Funding Support: Department of Defense National Institutes of Health Albert Einstein College of Medicine Montefiore Medical Center Name: Alexander...agency and compliance with research regulations. Funding Support: Department of Defense National Institutes of Health Albert Einstein College of

Einstein's Approach to Statistical Mechanics: The 1902-04 Papers

NASA Astrophysics Data System (ADS)

Peliti, Luca; Rechtman, Raúl

2017-05-01

We summarize the papers published by Einstein in the Annalen der Physik in the years 1902-1904 on the derivation of the properties of thermal equilibrium on the basis of the mechanical equations of motion and of the calculus of probabilities. We point out the line of thought that led Einstein to an especially economical foundation of the discipline, and to focus on fluctuations of the energy as a possible tool for establishing the validity of this foundation. We also sketch a comparison of Einstein's approach with that of Gibbs, suggesting that although they obtained similar results, they had different motivations and interpreted them in very different ways.

New non-naturally reductive Einstein metrics on exceptional simple Lie groups

NASA Astrophysics Data System (ADS)

Chen, Huibin; Chen, Zhiqi; Deng, Shaoqiang

2018-01-01

In this article, we construct several non-naturally reductive Einstein metrics on exceptional simple Lie groups, which are found through the decomposition arising from generalized Wallach spaces. Using the decomposition corresponding to the two involutions, we calculate the non-zero coefficients in the formulas of the components of Ricci tensor with respect to the given metrics. The Einstein metrics are obtained as solutions of a system of polynomial equations, which we manipulate by symbolic computations using Gröbner bases. In particular, we discuss the concrete numbers of non-naturally reductive Einstein metrics for each case up to isometry and homothety.

Multiparticle dynamics in an expanding universe

NASA Astrophysics Data System (ADS)

Anderson, James L.

1995-11-01

Approximate equations of motion for multiparticle systems in an expanding Einstein-deSitter universe are derived from the Einstein-Maxwell field equations using the Einstein-Infeld-Hoffmann surface integral method. At the Newtonian level of approximation one finds that, in comoving coordinates, both the Newtonian gravitational and Coulomb interactions in these equations are multiplied by the inverse third power of the scale factor R(t) appearing in the Einstein-deSitter field and they acquire a cosmic ``drag'' term. Nevertheless, both the period and luminosity size of bound two-body systems whose period is small compared to the Hubble time are found to be independent of t.

BOOK REVIEW: The Legacy of Albert Einstein: A Collection of Essays in Celebration of the Year of Physics

NASA Astrophysics Data System (ADS)

Straumann, Norbert

2007-10-01

During the 'World Year of Physics' much has been written on the epoch-making 1905 papers of Albert Einstein and his later great contributions to physics. Why another book on the enormous impact of Einstein's work on 20th-century physics? The short answer is that the present collection of 13 relatively short essays on the legacy of Einstein by outstanding scientists is very pleasant to read and should be of interest to physicists of all branches. Beside looking back, most articles present later and topical developments, whose initiation began with the work of Einstein. During the year 2005, the growing recognition among physicists, historians, and philosophers of Einstein's revolutionary role in quantum theory was often emphasized. It is truly astonishing that most active physicists were largely unaware of this before. Fortunately, the article 'Einstein and the quantum' by V Singh puts the subject in perspective and describes all the main steps, beginning with the truly revolutionary 1905 paper on the light-quantum hypothesis and ending with Einstein's extension of the particle-wave duality to atoms and other particles in 1924 1925. The only point which, in my opinion, is not sufficiently emphasized in the discussion of the 1916 1917 papers on absorption and emission of radiation is the part on the momentum transfer in each elementary process. Einstein's result that there is a directed recoil hν/c—also for spontaneous emission—in complete contrast to classical theory, was particularly important to him. I enjoyed reading the articles on Brownian motion (S Majumdar), Bose Einstein condensation (N Kumar) and strongly correlated electrons (T Ramakrishnan), which are all written for non-experts. Connected with Einstein's most lasting work—general relativity—there are two articles on cosmology. The one by J Narlikar gives a brief historical account of the development that was initiated by the 1917 paper of Einstein. S Sarkar's essay emphasizes the remarkable recent observational progress in cosmology and the emergence of the 'cosmic concordance model', with dark matter and dark energy as the dominant components of the current universe. Their discovery is widely considered as the most direct evidence for fundamental physics beyond the standard model of particle physics. In an introductory section Sarkar recalls the main reasons why the cosmological constant (vacuum energy) problem is of a very profound nature. In spite of some interesting ideas, no satisfactory solution is in sight. The article by B Sathyapakhash on gravitational radiation provides a readable introduction to the status of current detectors and astronomical sources of gravitational radiation. Of great cosmological interest are planned searches for a stochastic background of gravitational waves that is expected to have been produced by quantum processes in the very early universe. More than the first third of the book is devoted to current speculative attempts at creating a quantum theory of gravity, possibly within a unified coherent description of the known four fundamental interactions. Thanks to the enormously large value of the Planck energy in comparison to elementary particle masses, physicists may maintain for a long time, with success, a schizophrenic attitude in working within the framework of our present understanding, based on quantum field theory and classical general relativity. That physics cannot stay with that was already pointed out by Einstein in 1916, as A Ashtekar recalls in his essay. 'Einstein and the search for unification' by D Gross is the first article of the present book. In this he describes the reasons why, for those working in speculative areas, 'Einstein remains an inspiration for his foresight, and his unyielding determination and courage'. This inspiration is also manifest in the essays by M Atiyah, A Sen, and A Dabholkar on string theory. Hopefully, this book will find many readers, especially among graduate students, who can get valuable impressions of what is interesting in physics and what some of the main open problems for future research are.

Bell's Inequalities for Any Spin

NASA Astrophysics Data System (ADS)

González-Robles, V. M.

John Ju Sakurai's classical book in quantum mechanics makes a very illuminative presentation that studies entangled states in a two spin s=1/2 particles system in a singlet state. A Bell's inequality emerges as a consequence. Bell's inequality is a relationship among observables that discriminates between Einstein's locality principle and the nonlocal point of view of orthodox quantum mechanics. Following Sakurai's style we propose, by making natural induction, a generalization for Bell's inequality for any two spin-s particles in a singlet state (s integer or half-integer). This inequality is expressed as a function of a θ parameter, which is a measure of the angle between two possible directions in which the spin is measured. Besides the expression for this general inequality we have found that - (a) for any finite half-integer spin Bell's inequality is violated for some interval of the θ-parameter. The right limit of this interval is fixed and equal to π/2, while the left one comes closer and closer to this value as spin number grows. A function fit shows clearly that the size of this θ-interval over which Bell's inequality is violated diminishes asymptotically to zero as 1/s1/2; (b) an analogous behavior for any finite integer spin. For large spins the disagreement between Einstein's locality principle and the nonlocal point of view in orthodox quantum mechanics disappears.

Einstein-Podolsky-Rosen-entangled motion of two massive objects

NASA Astrophysics Data System (ADS)

Schnabel, Roman

2015-07-01

In 1935, Einstein, Podolsky, and Rosen (EPR) considered two particles in an entangled state of motion to illustrate why they questioned the completeness of quantum theory. In past decades, microscopic systems with entanglement in various degrees of freedom have successfully been generated, representing compelling evidence to support the completeness of quantum theory. Today, the generation of an EPR-entangled state of motion of two massive objects of up to the kilogram scale seems feasible with state-of-the-art technology. Recently, the generation and verification of EPR-entangled mirror motion in interferometric gravitational wave detectors was proposed, with the aim of testing quantum theory in the regime of macroscopic objects, and to make available nonclassical probe systems for future tests of modified quantum theories that include (nonrelativistic) gravity. The work presented here builds on these earlier results and proposes a specific Michelson interferometer that includes two high-quality laser mirrors of about 0.1 kg mass each. The mirrors are individually suspended as pendula and located close to each other, and cooled to about 4 K. The physical concepts for the generation of the EPR-entangled center-of-mass motion of these two mirrors are described. Apart from a test of quantum mechanics in the macroscopic world, the setup is envisioned to test predictions of yet-to-be-elaborated modified quantum theories that include gravitational effects.

Thermo-optically induced interactions in photon Bose-Einstein Condensates

NASA Astrophysics Data System (ADS)

Alaeian, Hadiseh; Bartels, Clara; Weitz, Martin

Bose-Einstein condensation (BEC), a new state of matter, emerges when the de Broglie wavelength of bosons becomes larger than the particle separation, leading to a macroscopic occupation of the system ground state. Followed by the first experimental demonstrations of BEC in cold atomic gases, this phase transition has been observed in other bosonic gases, as polaritons and phonons. The most recent one, photon BEC, is a promising candidate for a new generation of coherent photon sources. Due to their infancy, however, many of their properties are still unknown or only partly explored. In this talk I will present my latest results on the implications of photon interactions in photon BECs. In particular, I will investigate the effect of a thermo-optic non-linearity, leading to spatially non-local and delayed interactions. Starting from the steady state behavior, I will explore the spectrum of elementary excitations as a small perturbation. Moreover, I will discuss the resulting effective photon dispersion, manifesting various properties including possible superfluidity, as well as roton and maxon modes. The implications of physical parameters as absorption, number of photons in the condensate, and cavity trap on the dispersion will be discussed. The results of this study shed new light on the implication of interactions in photonic many-body systems. Hadiseh Alaeian acknowledges the generous support from Alexander von Humboldt Foundation.

Emergent universe with wormholes in massive gravity

NASA Astrophysics Data System (ADS)

Paul, B. C.; Majumdar, A. S.

2018-03-01

An emergent universe (EU) scenario is proposed to obtain a universe free from big-bang singularity. In this framework the present universe emerged from a static Einstein universe phase in the infinite past. A flat EU scenario is found to exist in Einstein’s gravity with a non-linear equation of state (EoS). It has been shown subsequently that a physically realistic EU model can be obtained considering cosmic fluid composed of interacting fluids with a non-linear equation of state. It results a viable cosmological model accommodating both early inflation and present accelerating phases. In the present paper, the origin of an initial static Einstein universe needed in the EU model is explored in a massive gravity theory which subsequently emerged to be a dynamically evolving universe. A new gravitational instanton solution in a flat universe is obtained in the massive gravity theory which is a dynamical wormhole that might play an important role in realizing the origin of the initial state of the emergent universe. The emergence of a Lorentzian universe from a Euclidean gravity is understood by a Wick rotation τ = i t . A universe with radiation at the beginning finally transits into the present observed universe with a non-linear EoS as the interactions among the fluids set in. Thus a viable flat EU scenario where the universe stretches back into time infinitely, with no big bang is permitted in a massive gravity.

The Stokes-Einstein relation at moderate Schmidt number.

PubMed

Balboa Usabiaga, Florencio; Xie, Xiaoyi; Delgado-Buscalioni, Rafael; Donev, Aleksandar

2013-12-07

The Stokes-Einstein relation for the self-diffusion coefficient of a spherical particle suspended in an incompressible fluid is an asymptotic result in the limit of large Schmidt number, that is, when momentum diffuses much faster than the particle. When the Schmidt number is moderate, which happens in most particle methods for hydrodynamics, deviations from the Stokes-Einstein prediction are expected. We study these corrections computationally using a recently developed minimally resolved method for coupling particles to an incompressible fluctuating fluid in both two and three dimensions. We find that for moderate Schmidt numbers the diffusion coefficient is reduced relative to the Stokes-Einstein prediction by an amount inversely proportional to the Schmidt number in both two and three dimensions. We find, however, that the Einstein formula is obeyed at all Schmidt numbers, consistent with linear response theory. The mismatch arises because thermal fluctuations affect the drag coefficient for a particle due to the nonlinear nature of the fluid-particle coupling. The numerical data are in good agreement with an approximate self-consistent theory, which can be used to estimate finite-Schmidt number corrections in a variety of methods. Our results indicate that the corrections to the Stokes-Einstein formula come primarily from the fact that the particle itself diffuses together with the momentum. Our study separates effects coming from corrections to no-slip hydrodynamics from those of finite separation of time scales, allowing for a better understanding of widely observed deviations from the Stokes-Einstein prediction in particle methods such as molecular dynamics.

The NASA Beyond Einstein Program

NASA Technical Reports Server (NTRS)

White, Nicholas E.

2006-01-01

Einstein's legacy is incomplete, his theory of General relativity raises -- but cannot answer --three profound questions: What powered the big bang? What happens to space, time, and matter at the edge of a black hole? and What is the mysterious dark energy pulling the Universe apart? The Beyond Einstein program within NASA's Office of Space Science aims to answer these questions, employing a series of missions linked by powerful new technologies and complementary approaches towards shared science goals. The Beyond Einstein program has three linked elements which advance science and technology towards two visions; to detect directly gravitational wave signals from the earliest possible moments of the BIg Bang, and to image the event horizon of a black hole. The central element is a pair of Einstein Great Observatories, Constellation-X and LISA. Constellation-X is a powerful new X-ray observatory dedicated to X-Ray Spectroscopy. LISA is the first spaced based gravitational wave detector. These powerful facilities will blaze new paths to the questions about black holes, the Big Bang and dark energy. The second element is a series of competitively selected Einstein Probes, each focused on one of the science questions and includes a mission dedicated resolving the Dark Energy mystery. The third element is a program of technology development, theoretical studies and education. The Beyond Einstein program is a new element in the proposed NASA budget for 2004. This talk will give an overview of the program and the missions contained within it.

Ceramic Electrolyte Membrane Technology: Enabling Revolutionary Electrochemical Energy Storage

DTIC Science & Technology

2015-10-05

ion batteries . Solid-state Li- ion batteries could significantly improve safety and eliminate the need for complex...advancing ceramic electrolyte technology for use in solid-state Li- ion batteries . Solid-state Li- ion batteries could significantly improve safety and...technology for use in solid-state Li- ion batteries and high specific energy Li-S and Li- air batteries . Solid-state Li- ion batteries could

An Examination of the Documentary Film "Einstein and Eddington" in Terms of Nature of Science Themes, Philosophical Movements, and Concepts

ERIC Educational Resources Information Center

Kapucu, Munise Seçkin

2016-01-01

This study aims to examine nature of science themes, philosophical movements, and overall concepts covered in the documentary film, "Einstein and Eddington". A qualitative research method was used. In this study, the documentary film "Einstein and Eddington," the viewing time of which is 1 hour and 28 minutes, was used as the…

Lenr:. Superfluids, Self-Trapping and Non-Self States

NASA Astrophysics Data System (ADS)

Chubb, Talbot A.

2005-12-01

LENR ion band state models involve deuteron many-body systems resembling superfluids. The physics of atom Bose-Einstein condensates in optical lattices teaches that superfluid behavior occurs when the potential barriers between adjacent potential wells permit high tunneling rates and the well potentials are shallow. These superfluids have fractional occupation of individual wells. Well periodic symmetry is not affected by the presence of the atoms. This behavior suggests that deuterons in a lattice should be in non-self-trapping sites, which may indicate that D+Bloch occupies the Pd tetrahedral sites.

Self-consistent modeling of electrochemical strain microscopy of solid electrolytes

DOE PAGES

Tselev, Alexander; Morozovska, Anna N.; Udod, Alexei; ...

2014-10-10

Electrochemical strain microscopy (ESM) employs a strong electromechanical coupling in solid ionic conductors to map ionic transport and electrochemical processes with nanometer-scale spatial resolution. To elucidate the mechanisms of the ESM image formation, we performed self-consistent numerical modeling of the electromechanical response in solid electrolytes under the probe tip in a linear, small-signal regime using the Boltzmann–Planck–Nernst–Einstein theory and Vegard's law while taking account of the electromigration and diffusion. We identified the characteristic time scales involved in the formation of the ESM response and found that the dynamics of the charge carriers in the tip-electrolyte system with blocking interfaces canmore » be described as charging of the diffuse layer at the tip-electrolyte interface through the tip contact spreading resistance. At the high frequencies used in the detection regime, the distribution of the charge carriers under the tip is governed by evanescent concentration waves generated at the tip-electrolyte interface. The ion drift length in the electric field produced by the tip determines the ESM response at high frequencies, which follows a 1/f asymptotic law. The electronic conductivity, as well as the electron transport through the electrode-electrolyte interface, do not have a significant effect on the ESM signal in the detection regime. The results indicate, however, that for typical solid electrolytes at room temperature, the ESM response originates at and contains information about the very surface layer of a sample, and the properties of the one-unit-cell-thick surface layer may significantly contribute to the ESM response, implying a high surface sensitivity and a high lateral resolution of the technique. On the other hand, it follows that a rigorous analysis of the ESM signals requires techniques that account for the discrete nature of a solid.« less

Packaging of solid state devices

DOEpatents

Glidden, Steven C.; Sanders, Howard D.

2006-01-03

A package for one or more solid state devices in a single module that allows for operation at high voltage, high current, or both high voltage and high current. Low thermal resistance between the solid state devices and an exterior of the package and matched coefficient of thermal expansion between the solid state devices and the materials used in packaging enables high power operation. The solid state devices are soldered between two layers of ceramic with metal traces that interconnect the devices and external contacts. This approach provides a simple method for assembling and encapsulating high power solid state devices.

EDITORIAL: Squeeze transformation and optics after Einstein

NASA Astrophysics Data System (ADS)

Kim, Young S.; Man'ko, Margarita A.; Planat, Michel

2005-12-01

With this special issue, Journal of Optics B: Quantum and Semiclassical Optics contributes to the celebration of the World Year of Physics held in recognition of five brilliant papers written by Albert Einstein in 1905. There is no need to explain to the readers of this journal the content and importance of these papers, which are cornerstones of modern physics. The 51 contributions in this special issue represent current trends in quantum optics —100 years after the concept of light quanta was introduced. At first glance, in his famous papers of 1905, Einstein treated quite independent subjects—special relativity, the nature and statistical properties of light, electrodynamics of moving bodies and Brownian motion. We now know that all these phenomena are deeply related, and these relations are clearly shown in many papers in this issue. Most of the papers are based on the talks and poster contributions from participants of the 9th International Conference on Squeezed States and Uncertainty Relations (ICSSUR'05), which took place in Besançon, France, 2-6 May, 2005. This was the continuation of a series of meetings, originating with the first workshops organized by Professor Y S Kim at the University of Maryland, College Park, USA, in 1991 and by Professor V I Man'ko at the Lebedev Physical Institute, Moscow in 1992. One of the main topics of ICSSUR'05 and this special issue is the theory and applications of squeezed states and their generalizations. At first glance, one could think that this subject has no relation to Einstein's papers. However, this is not true: the theory of squeezed states is deeply related to special relativity, as far as it is based on the representations of the Lorentz group (see the paper by Kim Y S and Noz M E, S458-S467), which also links the current concepts of entanglement and decoherence with Lorentz-covariance. Besides, studies of the different quantum states of light imply, after all, the study of photon (or photo-electron) statistics and fluctuations of the electromagnetic field, whose importance was first emphasized by Einstein in 1905. The squeezed states can also be considered as a generalization of the concept of coherent states, which turned out to be one of the most important theoretical tools for solving the numerous problems of quantum optics. It seems highly symbolical that the printed version of this special issue will appear in the same month when one of the prominent creators of the theory of coherent states and modern quantum optics—Professor Roy J Glauber—will receive his Nobel Prize in Stockholm. ICSSUR'05 was opened by the invited talk of R J Glauber, `What makes a quantum jump?', and we take great pleasure in congratulating him on this well deserved award. We are sure that all participants of ICSSUR'05 and all readers of this special issue share our feelings. Two other Nobel Prize winners of 2005—Professor J L Hall and Professor T W H\\"ansch—also made great contributions to quantum optics. In particular, in 1986, J L Hall with collaborators, performed the first experiments on the generation of squeezed states by parametric down conversion, having obtained squeezing at the 50% level (Wu L A, Kimble H J, Hall J L and Wu H 1986 Phys. Rev. Lett. 57 2520). Another area, which has attracted the attention of many researchers in the past decade and which is well represented in this special issue, is related to the problems of quantum correlations, entanglement and quantum nonlocality. It is also connected with the name of Einstein due to his famous `EPR' paper of 1935 written together with Podolsky and Rosen. For several decades this was an area of `thought experiments' only, but now this field is becoming a new part of physics, known as `quantum information'. The reader can find several papers which introduce new concepts in this area, such as applications of the Galois algebras and discrete Wigner functions. Solutions of different problems of the interaction between light and matter (which also take their origin in Einstein's paper of 1905), stationary and nonstationary Casimir effect, decoherence, new forms of uncertainty relations and their experimental verification, etc, can also be found in this issue. Many other contributions will be published in another special issue of the International Journal of Modern Physics B entitled `Quantum Information in Modern Optics'. This special issue is also the last issue of Journal of Optics B: Quantum and Semiclassical Optics. For the past 15 years this journal and its predecessors—Quantum Optics and Quantum and Semiclassical Optics—gained great respect among the quantum optics community. Many breakthrough papers were published in its pages during this period (see, for example, Schrade G, Man'ko V I, Schleich W P and Glauber R J 1995 Wigner Functions in the Paul trap Quantum Semiclass. Opt. 7 307). Since 1999, Journal of Optics B: Quantum and Semiclassical Optics has published a special issue for each ICSSUR meeting. This is the fourth issue of this series. We would like to thank Institute of Physics Publishing and the staff of Journal of Optics B: Quantum and Semiclassical Optics for providing the opportunity to pursue this programme, hoping that such a cooperation will continue in the future. We would also like to thank the many colleagues, who served as referees and whose efforts helped immensely in the preparation of this issue at such a high standard. The 10th ICSSUR conference will be organized for 2007 in Bradford, UK, by Professor A Vourdas. We invite readers to join us in two years.

Matter-wave entanglement and teleportation by molecular dissociation and collisions.

PubMed

Opatrný, T; Kurizki, G

2001-04-02

We propose dissociation of cold diatomic molecules as a source of atom pairs with highly correlated (entangled) positions and momenta, approximating the original quantum state introduced by Einstein, Podolsky, and Rosen (EPR) [Phys. Rev. 47, 777 (1935)]. Wave packet teleportation is shown to be achievable by its collision with one of the EPR correlated atoms and manipulation of the other atom in the pair.

Matter-Wave Entanglement and Teleportation by Molecular Dissociation and Collisions

NASA Astrophysics Data System (ADS)

Opatrný, T.; Kurizki, G.

2001-04-01

We propose dissociation of cold diatomic molecules as a source of atom pairs with highly correlated (entangled) positions and momenta, approximating the original quantum state introduced by Einstein, Podolsky, and Rosen (EPR) [Phys. Rev. 47, 777 (1935)]. Wave packet teleportation is shown to be achievable by its collision with one of the EPR correlated atoms and manipulation of the other atom in the pair.

Enhancing the violation of the einstein-podolsky-rosen local realism by quantum hyperentanglement.

PubMed

Barbieri, Marco; De Martini, Francesco; Mataloni, Paolo; Vallone, Giuseppe; Cabello, Adán

2006-10-06

Mermin's observation [Phys. Rev. Lett. 65, 1838 (1990)] that the magnitude of the violation of local realism, defined as the ratio between the quantum prediction and the classical bound, can grow exponentially with the size of the system is demonstrated using two-photon hyperentangled states entangled in polarization and path degrees of freedom, and local measurements of polarization and path simultaneously.

The photon: Experimental emphasis on its wave-particle duality

NASA Technical Reports Server (NTRS)

Shih, Yan-Hua; Sergienko, A. V.; Rubin, Morton H.; Kiess, Thomas E.; Alley, Carroll O.

1994-01-01

Two types of Einstein-Podolsky-Rosen experiments were demonstrated recently in our laboratory. It is interesting to see that in an interference experiment (wave-like experiment) the photon exhibits its particle property, and in a beam-splitting experiment (particle-like experiment) the photon exhibits its wave property. The two-photon states are produced from Type 1 and Type 2 optical spontaneous parametric down conversion, respectively.

The interaction of Dirac particles with non-abelian gauge fields and gravity - bound states

NASA Astrophysics Data System (ADS)

Finster, Felix; Smoller, Joel; Yau, Shing-Tung

2000-09-01

We consider a spherically symmetric, static system of a Dirac particle interacting with classical gravity and an SU(2) Yang-Mills field. The corresponding Einstein-Dirac-Yang-Mills equations are derived. Using numerical methods, we find different types of soliton-like solutions of these equations and discuss their properties. Some of these solutions are stable even for arbitrarily weak gravitational coupling.

Measurement of Bose-Einstein correlations in e^+e^->W^+W^- events at LEP [rapid communication] L3 Collaboration, P. Achard, O. Adriani, M. Aguilar-Benitez, J. Alcaraz, G. Alemanni, J. Allaby, A. Aloisio, M.G. Alviggi, H. Anderhub, V.P. Andreev, F. Anselmo, A. Arefiev, T. Azemoon, T. Aziz,

NASA Astrophysics Data System (ADS)

Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Baldew, S. V.; Banerjee, S.; Banerjee, S.; Barczyk, A.; Barillere, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B. L.; Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J. J.; Blyth, S. C.; Bobbink, G. J.; Bohm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J. G.; Brochu, F.; Burger, J. D.; Burger, W. J.; Cai, X. D.; Capell, M.; Romeo, G. Cara; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chang, Y. H.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G. M.; Chen, H. F.; Chen, H. S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de la Cruz, B.; Cucciarelli, S.; van Dalen, J. A.; de Asmundis, R.; Deglon, P.; Debreczeni, J.; Degre, A.; Dehmelt, K.; Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; DeNotaristefani, F.; De Salvo, A.; Diemoz, M.; Dierckxsens, M.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M. T.; Duchesneau, D.; Echenard, B.; Eline, A.; El Mamouni, H.; Engler, A.; Eppling, F. J.; Ewers, A.; Extermann, P.; Falagan, M. A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H.; Fiandrini, E.; Field, J. H.; Filthaut, F.; Fisher, P. H.; Fisher, W.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Y.; Ganguli, S. N.; Garcia-Abia, P.; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z. F.; Grenier, G.; Grimm, O.; Gruenewald, M. W.; Guida, M.; van Gulik, R.; Gupta, V. K.; Gurtu, A.; Gutay, L. J.; Haas, D.; Hakobyan, R. S.; Hatzifotiadou, D.; Hebbeker, T.; Herve, A.; Hirschfelder, J.; Hofer, H.; Hohlmann, M.; Holzner, G.; Hou, S. R.; Hu, Y.; Jin, B. N.; Jones, L. W.; de Jong, P.; Josa-Mutuberra, I.; Kafer, D.; Kaur, M.; Kienzle-Focacci, M. N.; Kim, J. K.; Kirkby, J.; Kittel, W.; Klimentov, A.; Konig, A. C.; Kopal, M.; Koutsenko, V.; Kraber, M.; Kraemer, R. W.; Krenz, W.; Kruger, A.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Le Goff, J. M.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li, C.; Likhoded, S.; Lin, C. H.; Lin, W. T.; Linde, F. L.; Lista, L.; Liu, Z. A.; Lohmann, W.; Longo, E.; Lu, Y. S.; Lubelsmeyer, K.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W. G.; Malgeri, L.; Malinin, A.; Mana, C.; Mangeol, D.; Mans, J.; Martin, J. P.; Marzano, F.; Mazumdar, K.; McNeil, R. R.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W. J.; Mihul, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G. B.; Muanza, G. S.; Muijs, A. J. M.; Musicar, B.; Musy, M.; Nagy, S.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Niessen, T.; Nisati, A.; Nowak, H.; Ofierzynski, R.; Organtini, G.; Palomares, C.; Pandoulas, D.; Paolucci, P.; Paramatti, R.; Passaleva, G.; Patricelli, S.; Paul, T.; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Petersen, B.; Piccolo, D.; Pierella, F.; Pioppi, M.; Piroue, P. A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofiev, D. O.; Prokofiev, D.; Quartieri, J.; Rahal-Callot, G.; Rahaman, M. A.; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P. G.; Ranieri, R.; Raspereza, A.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Riemann, S.; Riles, K.; Roe, B. P.; Romero, L.; Rosca, A.; Rosier-Lees, S.; Roth, S.; Rosenbleck, C.; Roux, B.; Rubio, J. A.; Ruggiero, G.; Rykaczewski, H.; Sakharov, A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Sanders, M. P.; Schafer, C.; Schegelsky, V.; Schmidt-Kaerst, S.; Schmitz, D.; Schopper, H.; Schotanus, D. J.; Schwering, G.; Sciacca, C.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Siedenburg, T.; Son, D.; Souga, C.; Spillantini, P.; Steuer, M.; Stickland, D. P.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L. Z.; Sushkov, S.; Suter, H.; Swain, J. D.; Szillasi, Z.; Tang, X. W.; Tarjan, P.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, C.; Ting, C. C.; Ting, S. M.; Tonwar, S. C.; Toth, J.; Tully, C.; Tung, K. L.; Ulbricht, J.; Valente, E.; Van de Walle, R. T.; Vasquez, R.; Veszpremi, V.; Vesztergombi, G.; Vetlitsky, I.; Vicinanza, D.; Viertel, G.; Villa, S.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobiev, I.; Vorobyov, A. A.; Wadhwa, M.; Wallraff, W.; Wang, X. L.; Wang, Z. M.; Weber, M.; Wienemann, P.; Wilkens, H.; Wynhoff, S.; Xia, L.; Xu, Z. Z.; Yamamoto, J.; Yang, B. Z.; Yang, C. G.; Yang, H. J.; Yang, M.; Yeh, S. C.; Zalite, A.; Zalite, Y.; Zhang, Z. P.; Zhao, J.; Zhu, G. Y.; Zhu, R. Y.; Zhuang, H. L.; Zichichi, A.; Zimmermann, B.; Zoller, M.

2002-11-01

Bose-Einstein correlations in W-pair production at LEP are investigated in a data sample of 629 pb^-1 collected by the L3 detector at centre-of-mass energies of 189-209 GeV. Bose-Einstein correlations between pions within a W decay are observed and found to be in good agreement with those in light-quark Z decay. No evidence is found for Bose-Einstein correlations between hadrons coming from different W's in the same event.

The Einstein/CFA stellar survey - Overview of the data and interpretation of results

NASA Technical Reports Server (NTRS)

Vaiana, G. S.

1981-01-01

Results are presented from an extensive survey of stellar X-ray emission, using the Einstein Observatory. Over 140 stars have been detected to date, throughout the H-R diagram, thus showing that soft X-ray emission is the norm rather than the exception for stars in general. This finding is strongly at odds with pre-Einstein expectations based on standard acoustic theories of coronal heating. Typical examples of stellar X-ray detections and an overview of the survey data are presented. In combination with recent results from solar X-ray observations, the new Einstein data argue for the general applicability of magnetic field-related coronal heating mechanisms.

Einstein and a century of time

NASA Astrophysics Data System (ADS)

Raine, D. J.

2005-09-01

In a world overabundant in information, a subject is defined by its iconography. Physics is the falling apple, the planetary atom, the laser, the mushroom cloud and the image of the later Einstein - images that represent, respectively, gravity, atomic theory, quantum theory, mass-energy and the scientist who had a hand in all four. It is therefore appropriate that World Year of Physics is called Einstein Year in the UK. Of course one can argue that progress in science depends on the contributions of many people; that there are other geniuses in physics, even some colourful personalities. Nevertheless there are fundamental reasons why Einstein's early achievements stand out even in their company. When at last the thought came to him that 'time itself was suspect', Einstein had found a new insight into the nature of the physical universe. It is this: that the universal properties of material objects tell us about the nature of space and time, and it is through these properties, not philosophical logic or common sense, that we discover the structure of spacetime. The later Einstein turned this successful formula on its head and sought to use the properties of spacetime to define those of material objects, thereby seeking to abolish matter entirely in favour of geometry. Before I introduce this special feature of European Journal of Physics I will say a few words about what is not here. Like all great geniuses Einstein can be seen as the climax of what went before him and the initiation of what was to follow. Looking back we can see the influence of Mach's positivism, according to which the role of science is to relate observations to other observations; hence only observations can tell us what is 'real'. But Einstein also grew up with the family electromechanical businesses, which testifies to the reality of the Maxwellian electromagnetic fields: thus only theory can tell us what is real! As is well known, Einstein himself refused to accept the full consequences of this pivotal insight into the role of theory when it came to quantum mechanics. Much has been written about this and we do not add to it in this collection. Quantum theory is a consistent description of nature whatever Einstein may think of 'god' for making it so. Many of us would side with Einstein in hoping it will yet turn out not to be a complete description. This will not happen, as Einstein hoped throughout his later work, from a return to classical field theory. But quantum behaviour is a universal property of matter and may therefore be expected, according to Einstein's way of thought, to have a geometrical origin. The advent of non-commutative quantum geometries may turn out to be a step in this direction. My own introduction to Einstein's physics was through what has come to be known as Mach's principle. My research supervisor, Dennis Sciama, in what he always claimed was probably Einstein's last significant scientific conversation, talked with him on this subject, during which Einstein explained that he had abandoned the idea of Mach's principle. This principle had been a guiding thought in the development of general relativity, but superfluous to its final exposition. It can be interpreted variously as the determination of the local compass of inertia by the distant stars, the non-rotation of the Universe or, more restrictedly, as requiring a critical density universe (to generate the right amount of inertia). This last formulation amounts to Gρτ2 approx 1, where ρ is the density of the Universe at time τ. This appears to be a classical expression, which would probably be sufficient to relegate Mach's principle to mere historical interest along with the classical unified field theories. It is also usually considered to be accounted for by inflation, which drives the Universe to Ω=1. However, we can also think of the expression as saying that the Universe has a Planck mass in a Planck volume at the Planck time: G=(hc / G)1/2(c3 / Gh)3/2(Gh / c5)=1. This suggests that Mach's principle may yet have a surprising role in expressing the fact that the Universe contains sufficient matter to exist as a classical system: that is, that it contains sufficient material degrees of freedom to allow quantum decoherence to occur. It would at least be a nice irony if Mach's principle turned out to be a necessary quantum condition for the existence of a classical universe! Coming now to the papers in this special feature, these include several that treat historical aspects of relativity. Brown offers us a novel insight into Einstein's ambivalence about the status of special relativity in providing a mechanism for the contraction hypothesis. Trainer looks at the way in which Einstein presented a brief account of relativity in a lecture that he gave in Glasgow in 1933. Galvangno and Giribet look at Einstein's approach to the representation of particles within general relativity, or variants thereof, while Battimelli provides an account of attempts at unification of electromagnetism and relativity from the point of view of the origin of mass. In their contribution, Guerra and de Abreu look again at the relationship between the constancy of the speed of light and the nature of time that was central to Einstein's thinking. Next we come to a group of papers that look at educational issues. Einstein's equation E = mc2 is now iconic even if general knowledge quizzes that ask what the c stands for miss the entire point of the equation! Thomas starts from the way in which perceptions of relativity still focus on this equation as the essential ingredient of nuclear power and the need to disabuse even students of physics of this notion. He also looks at how we can in fact demonstrate the significance of the equation to a lay audience. I have added a short note on friction, another topic that confuses teachers and students alike, that throws up problems to which the solutions are contained in Einstein's Brownian motion paper. The Open University in the UK has been teaching relativity to distance-learners for forty years; Lambourne writes about the experience that has been gained. Finally, I have always been intrigued by the opprobrium that Einstein seems to attract from crank authors. I no longer regularly receive such nonsense to referee, I assume because the internet is now awash with 'publication' opportunities for anti-Einstein articles. I do believe however that the work of these authors throws light on the way science works and I have tried to illustrate this thesis briefly in the final paper of this collection.

The Evolution of Hyperedge Cardinalities and Bose-Einstein Condensation in Hypernetworks.

PubMed

Guo, Jin-Li; Suo, Qi; Shen, Ai-Zhong; Forrest, Jeffrey

2016-09-27

To depict the complex relationship among nodes and the evolving process of a complex system, a Bose-Einstein hypernetwork is proposed in this paper. Based on two basic evolutionary mechanisms, growth and preference jumping, the distribution of hyperedge cardinalities is studied. The Poisson process theory is used to describe the arrival process of new node batches. And, by using the Poisson process theory and a continuity technique, the hypernetwork is analyzed and the characteristic equation of hyperedge cardinalities is obtained. Additionally, an analytical expression for the stationary average hyperedge cardinality distribution is derived by employing the characteristic equation, from which Bose-Einstein condensation in the hypernetwork is obtained. The theoretical analyses in this paper agree with the conducted numerical simulations. This is the first study on the hyperedge cardinality in hypernetworks, where Bose-Einstein condensation can be regarded as a special case of hypernetworks. Moreover, a condensation degree is also discussed with which Bose-Einstein condensation can be classified.

The NASA Beyond Einstein Program

NASA Technical Reports Server (NTRS)

White, Nicholas E.

2004-01-01

The Laser Interferometer Space Antenna (LISA) mission is part of NASA s Beyond Einstein program. This program seeks to answer the questions What Powered the Big Bang?, What happens at the edge of a Black Hole?, and What is Dark Energy?. LISA IS the first mission to be launched in this new program. This paper will give an overview of the Beyond Einstein program, its current status and where LISA fits in.

It’s About Time -- Understanding China’s Strategic Patience

DTIC Science & Technology

2012-03-18

Einstein and Stephen 3 Hawking, made conceptualizing time easier to accept by linking time with space. Time and space are inherently linked together...same regardless of how you were moving - exactly as experiments and mathematics of the day showed them to be. In 1905, Albert Einstein published...speeds relative to each other. Einstein explained that when two objects are moving at independent constant speeds, emphasizing the relative motion

Scalar field coupling to Einstein tensor in regular black hole spacetime

NASA Astrophysics Data System (ADS)

Zhang, Chi; Wu, Chen

2018-02-01

In this paper, we study the perturbation property of a scalar field coupling to Einstein's tensor in the background of the regular black hole spacetimes. Our calculations show that the the coupling constant η imprints in the wave equation of a scalar perturbation. We calculated the quasinormal modes of scalar field coupling to Einstein's tensor in the regular black hole spacetimes by the 3rd order WKB method.

Einstein-Cartan Gravity with Torsion Field Serving as an Origin for the Cosmological Constant or Dark Energy Density

NASA Astrophysics Data System (ADS)

Ivanov, A. N.; Wellenzohn, M.

2016-09-01

We analyse the Einstein-Cartan gravity in its standard form { R }=R+{{ K }}2, where { R } {and} R are the Ricci scalar curvatures in the Einstein-Cartan and Einstein gravity, respectively, and {{ K }}2 is the quadratic contribution of torsion in terms of the contorsion tensor { K }. We treat torsion as an external (or background) field and show that its contribution to the Einstein equations can be interpreted in terms of the torsion energy-momentum tensor, local conservation of which in a curved spacetime with an arbitrary metric or an arbitrary gravitational field demands a proportionality of the torsion energy-momentum tensor to a metric tensor, a covariant derivative of which vanishes owing to the metricity condition. This allows us to claim that torsion can serve as an origin for the vacuum energy density, given by the cosmological constant or dark energy density in the universe. This is a model-independent result that may explain the small value of the cosmological constant, which is a long-standing problem in cosmology. We show that the obtained result is valid also in the Poincaré gauge gravitational theory of Kibble, where the Einstein-Hilbert action can be represented in the same form: { R }=R+{{ K }}2.

Structural evolution and atomic dynamics in Ni-Nb metallic glasses: A molecular dynamics study

NASA Astrophysics Data System (ADS)

Xu, T. D.; Wang, X. D.; Zhang, H.; Cao, Q. P.; Zhang, D. X.; Jiang, J. Z.

2017-10-01

The composition and temperature dependence of static and dynamic structures in NixNb1-x (x = 50-70 at. %) were systematically studied using molecular dynamics with a new-released semi-empirical embedded atom method potential by Mendelev. The calculated pair correlation functions and the structure factor match well with the experimental data, demonstrating the reliability of the potential within relatively wide composition and temperature ranges. The local atomic structures were then characterized by bond angle distributions and Voronoi tessellation methods, demonstrating that the icosahedral ⟨0,0,12,0⟩ is only a small fraction in the liquid state but increases significantly during cooling and becomes dominant at 300 K. The most abundant clusters are identified as ⟨0,0,12,0⟩ and distorted icosahedron ⟨0,2,8,2⟩. The large fraction of these two clusters hints that the relatively good glass forming ability is near the eutectic point. Unlike Cu-Zr alloys, both the self-diffusion coefficient and shear viscosity are insensitive to compositions upon cooling in Ni-Nb alloys. The breakdown of the Stokes-Einstein relation happens at around 1.6Tg (Tg: glass transition temperature). In the amorphous state, the solid and liquid-like atoms can be distinguished based on the Debye-Waller factor ⟨u2⟩. The insensitivity of the dynamic properties of Ni-Nb alloys to compositions may result from the relatively simple solidification process in the phase diagram, in which only one eutectic point exists in the studied composition range.

Solid state recorders for airborne reconnaissance

NASA Astrophysics Data System (ADS)

Klang, Mark R.

2003-08-01

Solid state recorders have become the recorder of choice for meeting airborne ruggedized requirements for reconnaissance and flight test. The cost of solid state recorders have decreased over the past few years that they are now less expense than the traditional high speed tape recorders. CALCULEX, Inc manufactures solid state recorders called MONSSTR (Modular Non-volatile Solid State Recorder). MONSSTR is being used on many different platforms such as F/A-22, Global Hawk, F-14, F-15, F-16, U-2, RF-4, and Tornado. This paper will discuss the advantages of using solid state recorders to meet the airborne reconnaissance requirement and the ability to record instrumentation data. The CALCULEX recorder has the ability to record sensor data and flight test data in the same chassis. This is an important feature because it eliminates additional boxes on the aircraft. The major advantages to using a solid state recorder include; reliability, small size, light weight, and power. Solid state recorders also have a larger storage capacity and higher bandwidth capability than other recording devices.

The solid-state terahertz spectrum of MDMA (Ecstasy) - A unique test for molecular modeling assignments

NASA Astrophysics Data System (ADS)

Allis, Damian G.; Hakey, Patrick M.; Korter, Timothy M.

2008-10-01

The terahertz (THz, far-infrared) spectrum of 3,4-methylene-dioxymethamphetamine hydrochloride (Ecstasy) is simulated using solid-state density functional theory. While a previously reported isolated-molecule calculation is noteworthy for the precision of its solid-state THz reproduction, the solid-state calculation predicts that the isolated-molecule modes account for only half of the spectral features in the THz region, with the remaining structure arising from lattice vibrations that cannot be predicted without solid-state molecular modeling. The molecular origins of the internal mode contributions to the solid-state THz spectrum, as well as the proper consideration of the protonation state of the molecule, are also considered.

On the Correlations between the Particles in the EPR-Paradoxon

NASA Astrophysics Data System (ADS)

Treder, H.-J.

The Einstein-Podolsky-Rosen gedanken-experiment does not imply non-local interactions or an action-at-a-distance.Contrary, the EPR proves the measurements at one particle does not have influences at canonical variables of the other particles if the quantum-mechanical commutation relations are true.But, the EPR implices correlations between the particles which come in by subjective knowledge. These correlations are a priori informations about the relative motion or, complementarily, about the motion of the center of mass. The impression of an action-at-a-distance is produced by the use of usual particle coordinates in the EPR-arrangements.The discussion of the Einstein-Podolsky-Rosen gedanken-experiment (EPR) has been going on over fifty years. EINSTEIN, PODOLSKY, and ROSEN formulated their famous paradox in 1935, and in the discussion between N. BOHR (1935, 1949) and A. EINSTEIN (1936, 1948); A. EINSTEIN (1948) made his point that the EPR implied an action-at-a-distance for quantum-mechanical particles (without obvious classical interactions). His argument is the starting point for the recent discussion about EPR and causality (see A. Aspect, 1981).Translated AbstractÜber die Korrelationen zwischen den Partikeln beim EPR-ParadoxonDas Gedankenexperiment von EINSTEIN, PODOLSKY und ROSEN über die anscheinend paradoxen Beziehungen zwischen beliebig weit entfernten Partikeln gemäß der quantenmechanischen Theorie der Messungen führt tatsächlich nicht auf nichtlokale Wechselwirkungen.Das Einstein-Podolsky-Rosen-Paradoxon zeigt vielmehr, daß die Messung an einem Teilchen keinerlei Einfluß auf die Meßwerte an anderen Partikeln hat, wenn die quantenmechanischen Vertauschungsregeln erfüllt sind.Dagegen weist das Einstein-Podolsky-Rosensche Gedankenexperiment Korrelationen zwischen den Teilchen auf, die die Folge einer a-priori-Kenntnis über die Werte von Hamilton-Jacobischen Zwei-Partikeln-Koordinaten von nicht-wechselwirkenden Teilchen sind.

Solid state lighting devices and methods with rotary cooling structures

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

Koplow, Jeffrey P.

Solid state lighting devices and methods for heat dissipation with rotary cooling structures are described. An example solid state lighting device includes a solid state light source, a rotating heat transfer structure in thermal contact with the solid state light source, and a mounting assembly having a stationary portion. The mounting assembly may be rotatably coupled to the heat transfer structure such that at least a portion of the mounting assembly remains stationary while the heat transfer structure is rotating. Examples of methods for dissipating heat from electrical devices, such as solid state lighting sources are also described. Heat dissipationmore » methods may include providing electrical power to a solid state light source mounted to and in thermal contact with a heat transfer structure, and rotating the heat transfer structure through a surrounding medium.« less

Realization of two-dimensional spin-orbit coupling for Bose-Einstein condensates.

PubMed

Wu, Zhan; Zhang, Long; Sun, Wei; Xu, Xiao-Tian; Wang, Bao-Zong; Ji, Si-Cong; Deng, Youjin; Chen, Shuai; Liu, Xiong-Jun; Pan, Jian-Wei

2016-10-07

Cold atoms with laser-induced spin-orbit (SO) interactions provide a platform to explore quantum physics beyond natural conditions of solids. Here we propose and experimentally realize two-dimensional (2D) SO coupling and topological bands for a rubidium-87 degenerate gas through an optical Raman lattice, without phase-locking or fine-tuning of optical potentials. A controllable crossover between 2D and 1D SO couplings is studied, and the SO effects and nontrivial band topology are observed by measuring the atomic cloud distribution and spin texture in momentum space. Our realization of 2D SO coupling with advantages of small heating and topological stability opens a broad avenue in cold atoms to study exotic quantum phases, including topological superfluids. Copyright © 2016, American Association for the Advancement of Science.

Record bid for Einstein letter

NASA Astrophysics Data System (ADS)

Jeandron, Michelle

2008-06-01

A letter written by Albert Einstein the year before his death has sold for the staggering amount of £170 000 at an auction in London last month. The previously unrecorded letter, which has spent the past 50 years in a private collection, includes a discussion of Einstein's views on religion, bringing new material to the debate about whether or not he believed in God. The lot had been expected to fetch between £6000-£8000.

NAVO MSRC Navigator. Fall 2008

DTIC Science & Technology

2008-01-01

arrival of our two new HPC systems, DAVINCI (IBM P6) and EINSTEIN (Cray XT5), and our new mass storage server, NEWTON (Sun M5000). “The most...will run on both DAVINCI and EINSTEIN, providing researchers with the capability of running jobs of up to 4,256 and 12,736 cores in size...are expected to double as EINSTEIN and DAVINCI are brought online. We have also strengthened the backbone of our Disaster Recovery infrastructure, as

E=mc2 in theory and in practice

NASA Astrophysics Data System (ADS)

Friedlander, Michael W.

2009-02-01

Einstein and Oppenheimer are forever linked by that famous equation. Einstein derived it and Oppenheimer oversaw its terrible application. The Meaning of Genius is the subtitle that Silvan Schweber has chosen for his study of these two very different giants. Schweber is a theoretical physicist whose years at the Institute for Advanced Study in Princeton overlapped with those of Einstein and Oppenheimer, for whom he provides a perceptive comparison in his book's introductory chapter.

Einstein gravity with torsion induced by the scalar field

NASA Astrophysics Data System (ADS)

Özçelik, H. T.; Kaya, R.; Hortaçsu, M.

2018-06-01

We couple a conformal scalar field in (2+1) dimensions to Einstein gravity with torsion. The field equations are obtained by a variational principle. We could not solve the Einstein and Cartan equations analytically. These equations are solved numerically with 4th order Runge-Kutta method. From the numerical solution, we make an ansatz for the rotation parameter in the proposed metric, which gives an analytical solution for the scalar field for asymptotic regions.

Learning and Teaching: Where Does Einstein's Concept of Learning about "Service of Our Fellow Man" Enter into Our Discussions about Student Achievement?

ERIC Educational Resources Information Center

Manthey, George

2005-01-01

The author of this paper discusses the significance of Albert Einstein's concept of learning about "service of our fellow man" into the discussions about student achievement. Albert Einstein wrote in 1954 of what he considered an evil of modern life--that the "individual feels more than ever dependent on society, but it is not felt in the positive…

Cosmological perturbations during the Bose-Einstein condensation of dark matter

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

Freitas, R.C.; Gonçalves, S.V.B., E-mail: rodolfo.camargo@pq.cnpq.br, E-mail: sergio.vitorino@pq.cnpq.br

In the present work, we analyze the evolution of the scalar and tensorial perturbations and the quantities relevant for the physical description of the Universe, as the density contrast of the scalar perturbations and the gravitational waves energy density during the Bose-Einstein condensation of dark matter. The behavior of these parameters during the Bose-Einstein phase transition of dark matter is analyzed in details. To study the cosmological dynamics and evolution of scalar and tensorial perturbations in a Universe with and without cosmological constant we use both analytical and numerical methods. The Bose-Einstein phase transition modifies the evolution of gravitational wavesmore » of cosmological origin, as well as the process of large-scale structure formation.« less

Generalized Einstein relation for the mutual diffusion coefficient of a binary fluid mixture.

PubMed

Felderhof, B U

2017-08-21

The method employed by Einstein to derive his famous relation between the diffusion coefficient and the friction coefficient of a Brownian particle is used to derive a generalized Einstein relation for the mutual diffusion coefficient of a binary fluid mixture. The expression is compared with the one derived by de Groot and Mazur from irreversible thermodynamics and later by Batchelor for a Brownian suspension. A different result was derived by several other workers in irreversible thermodynamics. For a nearly incompressible solution, the generalized Einstein relation agrees with the expression derived by de Groot and Mazur. The two expressions also agree to first order in solute density. For a Brownian suspension, the result derived from the generalized Smoluchowski equation agrees with both expressions.

Hidden simplicity of the gravity action

DOE PAGES

Cheung, Clifford; Remmen, Grant N.

2017-09-01

We derive new representations of the Einstein-Hilbert action in which graviton perturbation theory is immensely simplified. To accomplish this, we recast the Einstein-Hilbert action as a theory of purely cubic interactions among gravitons and a single auxiliary field. The corresponding equations of motion are the Einstein field equations rewritten as two coupled first-order differential equations. Since all Feynman diagrams are cubic, we are able to derive new off-shell recursion relations for tree-level graviton scattering amplitudes. With a judicious choice of gauge fixing, we then construct an especially compact form for the Einstein-Hilbert action in which all graviton interactions are simplymore » proportional to the graviton kinetic term. Our results apply to graviton perturbations about an arbitrary curved background spacetime.« less

Hidden simplicity of the gravity action

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

Cheung, Clifford; Remmen, Grant N.

We derive new representations of the Einstein-Hilbert action in which graviton perturbation theory is immensely simplified. To accomplish this, we recast the Einstein-Hilbert action as a theory of purely cubic interactions among gravitons and a single auxiliary field. The corresponding equations of motion are the Einstein field equations rewritten as two coupled first-order differential equations. Since all Feynman diagrams are cubic, we are able to derive new off-shell recursion relations for tree-level graviton scattering amplitudes. With a judicious choice of gauge fixing, we then construct an especially compact form for the Einstein-Hilbert action in which all graviton interactions are simplymore » proportional to the graviton kinetic term. Our results apply to graviton perturbations about an arbitrary curved background spacetime.« less

The digital computer as a metaphor for the perfect laboratory experiment: Loophole-free Bell experiments

NASA Astrophysics Data System (ADS)

De Raedt, Hans; Michielsen, Kristel; Hess, Karl

2016-12-01

Using Einstein-Podolsky-Rosen-Bohm experiments as an example, we demonstrate that the combination of a digital computer and algorithms, as a metaphor for a perfect laboratory experiment, provides solutions to problems of the foundations of physics. Employing discrete-event simulation, we present a counterexample to John Bell's remarkable "proof" that any theory of physics, which is both Einstein-local and "realistic" (counterfactually definite), results in a strong upper bound to the correlations that are being measured in Einstein-Podolsky-Rosen-Bohm experiments. Our counterexample, which is free of the so-called detection-, coincidence-, memory-, and contextuality loophole, violates this upper bound and fully agrees with the predictions of quantum theory for Einstein-Podolsky-Rosen-Bohm experiments.