Sample records for single nuclear spin

  1. Dynamic nuclear polarization with single electron spins.

    PubMed

    Petta, J R; Taylor, J M; Johnson, A C; Yacoby, A; Lukin, M D; Marcus, C M; Hanson, M P; Gossard, A C

    2008-02-15

    We polarize nuclear spins in a GaAs double quantum dot by controlling two-electron spin states near the anticrossing of the singlet (S) and m(S)= +1 triplet (T+) using pulsed gates. An initialized S state is cyclically brought into resonance with the T+ state, where hyperfine fields drive rapid rotations between S and T+, "flipping" an electron spin and "flopping" a nuclear spin. The resulting Overhauser field approaches 80 mT, in agreement with a simple rate-equation model. A self-limiting pulse sequence is developed that allows the steady-state nuclear polarization to be set using a gate voltage. PMID:18352516

  2. Coherent Control of a Single Silicon-29 Nuclear Spin Qubit

    E-print Network

    Jarryd J. Pla; Fahd A. Mohiyaddin; Kuan Y. Tan; Juan P. Dehollain; Rajib Rahman; Gerhard Klimeck; David N. Jamieson; Andrew S. Dzurak; Andrea Morello

    2014-08-06

    Magnetic fluctuations caused by the nuclear spins of a host crystal are often the leading source of decoherence for many types of solid-state spin qubit. In group-IV materials, the spin-bearing nuclei are sufficiently rare that it is possible to identify and control individual host nuclear spins. This work presents the first experimental detection and manipulation of a single $^{29}$Si nuclear spin. The quantum non-demolition (QND) single-shot readout of the spin is demonstrated, and a Hahn echo measurement reveals a coherence time of $T_2 = 6.3(7)$ ms - in excellent agreement with bulk experiments. Atomistic modeling combined with extracted experimental parameters provides possible lattice sites for the $^{29}$Si atom under investigation. These results demonstrate that single $^{29}$Si nuclear spins could serve as a valuable resource in a silicon spin-based quantum computer.

  3. Detecting and Polarizing Nuclear Spins with Double Resonance on a Single Electron Spin

    NASA Astrophysics Data System (ADS)

    London, P.; Scheuer, J.; Cai, J.-M.; Schwarz, I.; Retzker, A.; Plenio, M. B.; Katagiri, M.; Teraji, T.; Koizumi, S.; Isoya, J.; Fischer, R.; McGuinness, L. P.; Naydenov, B.; Jelezko, F.

    2013-08-01

    We report the detection and polarization of nuclear spins in diamond at room temperature by using a single nitrogen-vacancy (NV) center. We use Hartmann-Hahn double resonance to coherently enhance the signal from a single nuclear spin while decoupling from the noisy spin bath, which otherwise limits the detection sensitivity. As a proof of principle, we (i) observe coherent oscillations between the NV center and a weakly coupled nuclear spin and (ii) demonstrate nuclear-bath cooling, which prolongs the coherence time of the NV sensor by more than a factor of 5. Our results provide a route to nanometer scale magnetic resonance imaging and novel quantum information processing protocols.

  4. Local probing of nuclear bath polarization with a single electronic spin

    E-print Network

    Paz London; Ran Fischer; Ignacio Alvizu; Jeronimo R. Maze; David Gershoni

    2015-05-22

    We demonstrate experimentally that a polarized nuclear spin modifies the dynamic behavior of a neighboring electronic spin. Specifically, an out-of-phase component appears in the electronic spin-echo signal. This component is proportional to the nuclear spin degree of polarization and strongly depends on the nuclear polarization direction. When the electronic spin is surrounded by a polarized nuclear spin bath, the spin-echo quadrature manifests a characteristic frequency related only to the nuclear spins abundance and their collective polarization. We use this analysis to propose a novel measurement method for the local nuclear spin bath of a single electronic spin. We quantify the realistic experimental regimes at which the scheme is efficient. Our proposal has potential applications for quantum sensing schemes, and opens a route for a systematic study of polarized mesoscopical-systems.

  5. Hyperfine switching triggered by resonant tunneling for the detection of a single nuclear spin qubit

    Microsoft Academic Search

    Tomofumi Tada

    2008-01-01

    A novel detection mechanism and a robust control of a single nuclear spin-flip by hyperfine interactions between the nuclear spin and tunneling electron spin are proposed on the basis of ab initio non-equilibrium Green's function calculations. The calculated relaxation times of the nuclear spin of proton in a nano-contact system, Pd(electrode)–H2–Pd(electrode), show that ON\\/OFF switching of hyperfine interactions is effectively

  6. Fast Electrical Control of Single Electron Spins in Quantum Dots with Vanishing Influence from Nuclear Spins

    NASA Astrophysics Data System (ADS)

    Yoneda, J.; Otsuka, T.; Nakajima, T.; Takakura, T.; Obata, T.; Pioro-Ladrière, M.; Lu, H.; Palmstrøm, C. J.; Gossard, A. C.; Tarucha, S.

    2014-12-01

    We demonstrate fast universal electrical spin manipulation with inhomogeneous magnetic fields. With fast Rabi frequency up to 127 MHz, we leave the conventional regime of strong nuclear-spin influence and observe a spin-flip fidelity >96 % , a distinct chevron Rabi pattern in the spectral-time domain, and a spin resonance linewidth limited by the Rabi frequency, not by the dephasing rate. In addition, we establish fast z rotations up to 54 MHz by directly controlling the spin phase. Our findings will significantly facilitate tomography and error correction with electron spins in quantum dots.

  7. Energy levels and decoherence properties of single electron and nuclear spins in a defect center in diamond

    E-print Network

    I. Popa; T. Gaebel; M. Domhan; C. Wittmann; F. Jelezko; J. Wrachtrup

    2004-09-12

    The coherent behavior of the single electron and single nuclear spins of a defect center in diamond and a 13C nucleus in its vicinity, respectively, are investigated. The energy levels associated with the hyperfine coupling of the electron spin of the defect center to the 13C nuclear spin are analyzed. Methods of magnetic resonance together with optical readout of single defect centers have been applied in order to observe the coherent dynamics of the electron and nuclear spins. Long coherence times, in the order of microseconds for electron spins and tens of microseconds for nuclear spins, recommend the studied system as a good experimental approach for implementing a 2-qubit gate.

  8. Protein carbon-13 spin systems by a single two-dimensional nuclear magnetic resonance experiment

    SciTech Connect

    Oh, B.H.; Westler, W.M.; Darba, P.; Markley, J.L.

    1988-05-13

    By applying a two-dimensional double-quantum carbon-13 nuclear magnetic resonance experiment to a protein uniformly enriched to 26% carbon-13, networks of directly bonded carbon atoms were identified by virtue of their one-bond spin-spin couplings and were classified by amino acid type according to their particular single- and double-quantum chemical shift patterns. Spin systems of 75 of the 98 amino acid residues in a protein, oxidized Anabaena 7120 ferredoxin (molecular weight 11,000), were identified by this approach, which represents a key step in an improved methodology for assigning protein nuclear magnetic resonance spectra. Missing spin systems corresponded primarily to residues located adjacent to the paramagnetic iron-sulfur cluster. 25 references, 2 figures.

  9. Fast Room-Temperature Phase Gate on a Single Nuclear Spin in Diamond

    E-print Network

    S. Sangtawesin; T. O. Brundage; J. R. Petta

    2014-07-14

    Nuclear spins support long lived quantum coherence due to weak coupling to the environment, but are difficult to rapidly control using nuclear magnetic resonance (NMR) as a result of the small nuclear magnetic moment. We demonstrate a fast ~ 500 ns nuclear spin phase gate on a 14N nuclear spin qubit intrinsic to a nitrogen-vacancy (NV) center in diamond. The phase gate is enabled by the hyperfine interaction and off-resonance driving of electron spin transitions. Repeated applications of the phase gate bang-bang decouple the nuclear spin from the environment, locking the spin state for up to ~ 140 microseconds.

  10. Fast Room-Temperature Phase Gate on a Single Nuclear Spin in Diamond

    NASA Astrophysics Data System (ADS)

    Sangtawesin, S.; Brundage, T. O.; Petta, J. R.

    2015-03-01

    Nuclear spins support long lived quantum coherence due to weak coupling to the environment, but are difficult to rapidly control using nuclear magnetic resonance as a result of the small nuclear magnetic moment. We demonstrate a fast ~ 500 ns nuclear spin phase gate on a 14N nuclear spin qubit intrinsic to a nitrogen-vacancy center in high purity diamond. This phase gate is achieved by utilizing electron-nuclear hyperfine interaction. By driving off-resonant Rabi oscillations on the electronic spin, we can generate an arbitrary phase gate on the nuclear spin. We also demonstrate that repeated applications of ?-phase gates can bang-bang decouple the nuclear spin from the environment, locking the spin state for up to 140 ?s. Research was supported by the Sloan and Packard Foundations, the National Science Foundation through Awards DMR-0819860 and DMR-0846341, and the Army Research Office through PECASE Award W911NF-08-1-0189.

  11. Quantum-state tomography of a single nuclear spin qubit of an optically manipulated ytterbium atom

    SciTech Connect

    Noguchi, Atsushi; Kozuma, Mikio [Department of Physics, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8550 (Japan); ERATO Macroscopic Quantum Control Project, JST, 2-11-16 Yayoi, Bunkyo-Ku, Tokyo 113-8656 (Japan); Eto, Yujiro [ERATO Macroscopic Quantum Control Project, JST, 2-11-16 Yayoi, Bunkyo-Ku, Tokyo 113-8656 (Japan); Ueda, Masahito [ERATO Macroscopic Quantum Control Project, JST, 2-11-16 Yayoi, Bunkyo-Ku, Tokyo 113-8656 (Japan); Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2011-09-15

    A single Yb atom is loaded into a high-finesse optical cavity with a moving lattice, and its nuclear spin state is manipulated using a nuclear magnetic resonance technique. A highly reliable quantum state control with fidelity and purity greater than 0.98 and 0.96, respectively, is confirmed by the full quantum state tomography; a projective measurement with high speed (500 {mu}s) and high efficiency (0.98) is accomplished using the cavity QED technique. Because a hyperfine coupling is induced only when the projective measurement is operational, the long coherence times (T{sub 1}=0.49 s and T{sub 2}=0.10 s) are maintained.

  12. Probing the effective nuclear-spin magnetic field in a single quantum dot via full counting statistics

    NASA Astrophysics Data System (ADS)

    Xue, Hai-Bin; Nie, Yi-Hang; Chen, Jingzhe; Ren, Wei

    2015-03-01

    We study theoretically the full counting statistics of electron transport through a quantum dot weakly coupled to two ferromagnetic leads, in which an effective nuclear-spin magnetic field originating from the configuration of nuclear spins is considered. We demonstrate that the quantum coherence between the two singly-occupied eigenstates and the spin polarization of two ferromagnetic leads play an important role in the formation of super-Poissonian noise. In particular, the orientation and magnitude of the effective field have a significant influence on the variations of the values of high-order cumulants, and the variations of the skewness and kurtosis values are more sensitive to the orientation and magnitude of the effective field than the shot noise. Thus, the high-order cumulants of transport current can be used to qualitatively extract information on the orientation and magnitude of the effective nuclear-spin magnetic field in a single quantum dot.

  13. Nuclear-spin-dependent coherent population trapping of single nitrogen vacancy centers in diamond

    E-print Network

    D. Andrew Golter; Khodadad N. Dinyari; Hailin Wang

    2013-03-02

    Coherent population trapping (CPT) provides a highly sensitive means for probing the energy level structure of an atomic system. For a nitrogen vacancy center in diamond, the CPT offers an alternative to the standard optically-detected magnetic resonance method for measuring the hyperfine structure of the electronic ground states. We show that the nuclear spin dependent CPT measures directly the hyperfine splitting of these states due to the 14N nuclear spin. The CPT spectral response obtained in the presence of a strong microwave field, resonant or nearly resonant with a ground state spin transition, maps out the dynamic Stark splitting induced by the coherent spin excitation.

  14. Quantum Hall Charge Sensor for Single-Donor Nuclear Spin Detection in Silicon

    E-print Network

    D. Sleiter; N. Y. Kim; K. Nozawa; T. D. Ladd; M. L. W. Thewalt; Y. Yamamoto

    2010-05-12

    We propose a novel optical and electrical hybrid scheme for the measurement of nuclear spin qubits in silicon. By combining the environmental insensitivity of the integer quantum Hall effect with the optically distinguishable hyperfine states of phosphorus impurities in silicon, our system can simultaneously offer nuclear spin measurement and robustness against environmental defects. 31P donor spins in isotopically purified 28Si are often discussed as very promising quantum memory qubits due to their extremely long decoherence times, and our proposed device offers an effective implementation for such a quantum memory system.

  15. Optical pumping of the electronic and nuclear spin of single charge-tunable quantum dots.

    PubMed

    Bracker, A S; Stinaff, E A; Gammon, D; Ware, M E; Tischler, J G; Shabaev, A; Efros, Al L; Park, D; Gershoni, D; Korenev, V L; Merkulov, I A

    2005-02-01

    We present a comprehensive examination of optical pumping of spins in individual GaAs quantum dots as we change the net charge from positive to neutral to negative with a charge-tunable heterostructure. Negative photoluminescence polarization memory is enhanced by optical pumping of ground state electron spins, which we prove with the first measurements of the Hanle effect on an individual quantum dot. We use the Overhauser effect in a high longitudinal magnetic field to demonstrate efficient optical pumping of nuclear spins for all three charge states of the quantum dot. PMID:15783594

  16. TRANSVERSITY SINGLE SPIN ASYMMETRIES.

    SciTech Connect

    BOER,D.

    2001-04-27

    The theoretical aspects of two leading twist transversity single spin asymmetries, one arising from the Collins effect and one from the interference fragmentation functions, are reviewed. Issues of factorization, evolution and Sudakov factors for the relevant observables are discussed. These theoretical considerations pinpoint the most realistic scenarios towards measurements of transversity.

  17. High-spin nuclear spectroscopy

    SciTech Connect

    Diamond, R.M.

    1986-07-01

    High-spin spectroscopy is the study of the changes in nuclear structure, properties, and behavior with increasing angular momentum. It involves the complex interplay between collective and single-particle motion, between shape and deformation changes, particle alignments, and changes in the pairing correlations. A review of progress in theory, experimentation, and instrumentation in this field is given. (DWL)

  18. Control of electron spin decoherence in nuclear spin baths

    NASA Astrophysics Data System (ADS)

    Liu, Ren-Bao

    2011-03-01

    Nuclear spin baths are a main mechanism of decoherence of spin qubits in solid-state systems, such as quantum dots and nitrogen-vacancy (NV) centers of diamond. The decoherence results from entanglement between the electron and nuclear spins, established by quantum evolution of the bath conditioned on the electron spin state. When the electron spin is flipped, the conditional bath evolution is manipulated. Such manipulation of bath through control of the electron spin not only leads to preservation of the center spin coherence but also demonstrates quantum nature of the bath. In an NV center system, the electron spin effectively interacts with hundreds of 13 C nuclear spins. Under repeated flip control (dynamical decoupling), the electron spin coherence can be preserved for a long time (> 1 ms) . Thereforesomecharacteristicoscillations , duetocouplingtoabonded 13 C nuclear spin pair (a dimer), are imprinted on the electron spin coherence profile, which are very sensitive to the position and orientation of the dimer. With such finger-print oscillations, a dimer can be uniquely identified. Thus, we propose magnetometry with single-nucleus sensitivity and atomic resolution, using NV center spin coherence to identify single molecules. Through the center spin coherence, we could also explore the many-body physics in an interacting spin bath. The information of elementary excitations and many-body correlations can be extracted from the center spin coherence under many-pulse dynamical decoupling control. Another application of the preserved spin coherence is identifying quantumness of a spin bath through the back-action of the electron spin to the bath. We show that the multiple transition of an NV center in a nuclear spin bath can have longer coherence time than the single transition does, when the classical noises due to inhomogeneous broadening is removed by spin echo. This counter-intuitive result unambiguously demonstrates the quantumness of the nuclear spin bath. This work was supported by Hong Kong RGC/GRF CUHK402207, CUHK402209, and CUHK402410. The author acknowledges collaboration with Nan Zhao, Jian-Liang Hu, Sai Wah Ho, Jones T. K. Wan, and Jiangfeng Du.

  19. Single-atom spin qubits in silicon

    NASA Astrophysics Data System (ADS)

    Dzurak, Andrew

    2013-03-01

    Spin qubits in silicon are excellent candidates for scalable quantum information processing (QIP) due to their long coherence times and the enormous investment in silicon MOS technology. Here I discuss qubits based upon single phosphorus (P) dopant atoms in Si. Projective readout of such qubits had proved challenging until single-shot measurement of a single donor electron spin was demonstrated using a silicon single electron transistor (Si-SET) and the process of spin-to-charge conversion. The measurement gave readout fidelities > 90% and spin lifetimes T1e > 6 s, opening the path to demonstration of electron and nuclear spin qubits in silicon. Integrating an on-chip microwave transmission line enabled single-electron spin resonance (ESR) of the P donor electron. We used this to demonstrate Rabi oscillations of the electron spin qubit, while a Hahn echo sequence revealed electron spin coherence times T2e > 0.2 ms. This time is expected to become much longer in isotopically enriched 28Si devices. We also achieved single-shot readout of the 31P nuclear spin (with fidelity > 99.6%) by monitoring the two hyperfine-split ESR lines of the P donor system. By applying (local) NMR pulses we demonstrated coherent control of the nuclear spin qubit, giving a coherence time T2n > 60 ms. Spin qubits in silicon are excellent candidates for scalable quantum information processing (QIP) due to their long coherence times and the enormous investment in silicon MOS technology. Here I discuss qubits based upon single phosphorus (P) dopant atoms in Si. Projective readout of such qubits had proved challenging until single-shot measurement of a single donor electron spin was demonstrated using a silicon single electron transistor (Si-SET) and the process of spin-to-charge conversion. The measurement gave readout fidelities > 90% and spin lifetimes T1e > 6 s, opening the path to demonstration of electron and nuclear spin qubits in silicon. Integrating an on-chip microwave transmission line enabled single-electron spin resonance (ESR) of the P donor electron. We used this to demonstrate Rabi oscillations of the electron spin qubit, while a Hahn echo sequence revealed electron spin coherence times T2e > 0.2 ms. This time is expected to become much longer in isotopically enriched 28Si devices. We also achieved single-shot readout of the 31P nuclear spin (with fidelity > 99.6%) by monitoring the two hyperfine-split ESR lines of the P donor system. By applying (local) NMR pulses we demonstrated coherent control of the nuclear spin qubit, giving a coherence time T2n > 60 ms. Device fabrication was undertaken at the Australian National Fabrication Facility. This work was supported by the Australian Research Council Centre for Quantum Computation and Communication Technology and the U.S. Army Research Office (W911NF-08-1-0527).

  20. High-dynamic-range magnetometry with a single nuclear spin in diamond

    E-print Network

    Pfeifer, Holger

    and measurement techniques2,3,5 because of its optical spin polariz- ation and readout mechanism10 , long-dependent energy difference is measured by monitoring the evolution of the corresponding phase f / Bt, where BT). If this priorinformation aboutthemagnetic fieldisnotavailable, estimation of B cannot be performed. To summarize, shorter

  1. Detection and Control of Individual Nuclear Spins Using a Weakly Coupled Electron Spin

    SciTech Connect

    Taminiau, T.H.; Wagenaar, J.J.T.; van der Sar, T.; Jelezko, F.; Dobrovitski, Viatcheslav V.; Hanson, R.

    2012-09-28

    We experimentally isolate, characterize, and coherently control up to six individual nuclear spins that are weakly coupled to an electron spin in diamond. Our method employs multipulse sequences on the electron spin that resonantly amplify the interaction with a selected nuclear spin and at the same time dynamically suppress decoherence caused by the rest of the spin bath. We are able to address nuclear spins with interaction strengths that are an order of magnitude smaller than the electron spin dephasing rate. Our results provide a route towards tomography with single-nuclear-spin sensitivity and greatly extend the number of available quantum bits for quantum information processing in diamond.

  2. Single spin stochastic optical reconstruction microscopy

    E-print Network

    Pfender, Matthias; Waldherr, Gerald; Wrachtrup, Jörg

    2014-01-01

    We experimentally demonstrate precision addressing of single quantum emitters by combined optical microscopy and spin resonance techniques. To this end we utilize nitrogen-vacancy (NV) color centers in diamond confined within a few ten nanometers as individually resolvable quantum systems. By developing a stochastic optical reconstruction microscopy (STORM) technique for NV centers we are able to simultaneously perform sub diffraction-limit imaging and optically detected spin resonance (ODMR) measurements on NV spins. This allows the assignment of spin resonance spectra to individual NV center locations with nanometer scale resolution and thus further improves spatial discrimination. For example, we resolved formerly indistinguishable emitters by their spectra. Furthermore, ODMR spectra contain metrology information allowing for sub diffraction-limit sensing of, for instance, magnetic or electric fields with inherently parallel data acquisition. As an example, we have detected nuclear spins with nanometer sca...

  3. Single- And Double-degenerate Models Of Type Ia Sne, Nuclear-burning White Dwarfs, Spin, And Supersoft X-ray Sources

    NASA Astrophysics Data System (ADS)

    Di Stefano, Rosanne; Voss, R.; Claeys, J. S. W.

    2011-09-01

    Over the past decade we have established that there are too few supersoft x-ray sources (SSSs) in galaxies of all types to support the hypothesis that the majority of Type Ia supernovae (SNeIa) progenitors pass through a long SSS phase. Yet, both single- and double-degenerate models predict long epochs during which a white dwarf receives mass at a rate compatible with nuclear burning. We explore the ways in which the link between nuclear-burning and SSS-like behavior can be broken. We also touch on the role that angular momentum (spin-up and spin-down) may have in changing the appearance of the progenitors just prior to explosion, and also the explosion and post-explosion signatures.

  4. Nuclear spin and isospin excitations

    Microsoft Academic Search

    Franz Osterfeld

    1992-01-01

    A review is given of our present knowledge of collective spin-isospin excitations in nuclei. Most of this knowledge comes from intermediate-energy charge-exchange reactions and from inelastic electron- and proton-scattering experiments. The nuclear-spin dynamics is governed by the spin-isospin-dependent two-nucleon interaction in the medium. This interaction gives rise to collective spin modes such as the giant Gamow-Teller resonances. An interesting phenomenon

  5. Observation of a single rare-earth ion in a crystal by electric-field modulation spectroscopy for a readout of a nuclear-spin qubit

    NASA Astrophysics Data System (ADS)

    Ichimura, Kouichi; Goto, Hayato; Nakamura, Satoshi; Kujiraoka, Mamiko

    2015-03-01

    Nuclear spin states of rare-earth-metal ions in a crystal are known as good candidates for qubits in solids because of their long coherence time and their good controllability by lights. In the frequency-domain quantum computer (FDQC), nuclear spin states of the ions are employed as qubits defined in a frequency domain, and interaction between the qubits is mediated by a single cavity mode. In FDQC we can use adiabatic passage with dark states to perform single-qubit gates and two-qubit gates, and a single-qubit gate using adiabatic passage has been demonstrated. For two-qubit gates, quantum states of qubit ions need to be read out and operated individually. In order to observe a single ion in a crystal, we studied modulated signals due to ions in a cavity-mode spectrum of a monolithic optical cavity made of Pr3+:Y2SiO5. Owing to the cavity enhancement and the electric-field modulation spectroscopy, signals which are likely due to individual ions (statistical fine structure in an inhomogeneously broadened optical trandition) were observed.

  6. Spin observables and nuclear geometry

    NASA Astrophysics Data System (ADS)

    McNeil, J. A.; Sparrow, D. A.; Amado, R. D.

    1982-09-01

    The new measurements of polarization P and spin rotation function Q in 500 MeV p-40Ca elastic scattering require geometric differences among the various parts of the p-nucleus interaction. We present a general analytic formalism which defines these differences and shows how the new experiments can be interpreted as interferometric determinations of them. NUCLEAR REACTIONS Closed form spin-dependent p-nucleus scattering amplitudes. Data-to-data relations for polarization and spin rotation.

  7. Robust control of individual nuclear spins in diamond

    E-print Network

    Benjamin Smeltzer; Jean McIntyre; Lilian Childress

    2009-09-22

    Isolated nuclear spins offer a promising building block for quantum information processing systems, but their weak interactions often impede preparation, control, and detection. Hyperfine coupling to a proximal electronic spin can enhance each of these processes. Using the electronic spin of the nitrogen-vacancy center as an intermediary, we demonstrate robust initialization, single-qubit manipulation, and direct optical readout of 13C, 15N, and 14N nuclear spins in diamond. These results pave the way for nitrogen nuclear spin based quantum information architectures in diamond.

  8. Quark Correlations and Single-Spin Asymmetries

    E-print Network

    Quark Correlations and Single-Spin Asymmetries Matthias Burkardt burkardt@nmsu.edu New Mexico State University Las Cruces, NM, 88003, U.S.A. Quark Correlations and Single-Spin Asymmetries ­ p.1 Implications for nucleon structure Summary Quark Correlations and Single-Spin Asymmetries ­ p.2/38 #12;What

  9. Nuclear spin noise imaging.

    PubMed

    Müller, Norbert; Jerschow, Alexej

    2006-05-01

    NMR images were obtained from the proton spin noise signals of a water-containing phantom, which was placed in the highly tuned, low-noise resonant circuit of a cryogenically cooled NMR probe in the presence of systematically varied magnetic field gradients. The spatially resolved proton spin density was obtained from the raw signal by a modified projection-reconstruction protocol. Although spin noise imaging is inherently less sensitive than conventional magnetic resonance imaging, it affords an entirely noninvasive visualization of the interior of opaque objects or subjects. Thus, tomography becomes possible even when neither x-ray nor radio frequency radiation can be applied for technical or safety reasons. PMID:16636281

  10. Uncovering many-body correlations in nanoscale nuclear spin baths by central spin decoherence

    NASA Astrophysics Data System (ADS)

    Ma, Wen-Long; Wolfowicz, Gary; Zhao, Nan; Li, Shu-Shen; Morton, John J. L.; Liu, Ren-Bao

    2014-09-01

    Central spin decoherence caused by nuclear spin baths is often a critical issue in various quantum computing schemes, and it has also been used for sensing single-nuclear spins. Recent theoretical studies suggest that central spin decoherence can act as a probe of many-body physics in spin baths; however, identification and detection of many-body correlations of nuclear spins in nanoscale systems are highly challenging. Here, taking a phosphorus donor electron spin in a 29Si nuclear spin bath as our model system, we discover both theoretically and experimentally that many-body correlations in nanoscale nuclear spin baths produce identifiable signatures in decoherence of the central spin under multiple-pulse dynamical decoupling control. We demonstrate that under control by an odd or even number of pulses, the central spin decoherence is principally caused by second- or fourth-order nuclear spin correlations, respectively. This study marks an important step toward studying many-body physics using spin qubits.

  11. Uncovering many-body correlations in nanoscale nuclear spin baths by central spin decoherence

    PubMed Central

    Ma, Wen-Long; Wolfowicz, Gary; Zhao, Nan; Li, Shu-Shen; Morton, John J.L.; Liu, Ren-Bao

    2014-01-01

    Central spin decoherence caused by nuclear spin baths is often a critical issue in various quantum computing schemes, and it has also been used for sensing single-nuclear spins. Recent theoretical studies suggest that central spin decoherence can act as a probe of many-body physics in spin baths; however, identification and detection of many-body correlations of nuclear spins in nanoscale systems are highly challenging. Here, taking a phosphorus donor electron spin in a 29Si nuclear spin bath as our model system, we discover both theoretically and experimentally that many-body correlations in nanoscale nuclear spin baths produce identifiable signatures in decoherence of the central spin under multiple-pulse dynamical decoupling control. We demonstrate that under control by an odd or even number of pulses, the central spin decoherence is principally caused by second- or fourth-order nuclear spin correlations, respectively. This study marks an important step toward studying many-body physics using spin qubits. PMID:25205440

  12. Single-spin stochastic optical reconstruction microscopy.

    PubMed

    Pfender, Matthias; Aslam, Nabeel; Waldherr, Gerald; Neumann, Philipp; Wrachtrup, Jörg

    2014-10-14

    We experimentally demonstrate precision addressing of single-quantum emitters by combined optical microscopy and spin resonance techniques. To this end, we use nitrogen vacancy (NV) color centers in diamond confined within a few ten nanometers as individually resolvable quantum systems. By developing a stochastic optical reconstruction microscopy (STORM) technique for NV centers, we are able to simultaneously perform sub-diffraction-limit imaging and optically detected spin resonance (ODMR) measurements on NV spins. This allows the assignment of spin resonance spectra to individual NV center locations with nanometer-scale resolution and thus further improves spatial discrimination. For example, we resolved formerly indistinguishable emitters by their spectra. Furthermore, ODMR spectra contain metrology information allowing for sub-diffraction-limit sensing of, for instance, magnetic or electric fields with inherently parallel data acquisition. As an example, we have detected nuclear spins with nanometer-scale precision. Finally, we give prospects of how this technique can evolve into a fully parallel quantum sensor for nanometer resolution imaging of delocalized quantum correlations. PMID:25267655

  13. Suppression of nuclear spin diffusion at a GaAs/AlGaAs interface measured with a single quantum dot nano-probe

    E-print Network

    A. E. Nikolaenko; E. A. Chekhovich; M. N. Makhonin; I. W. Drouzas; A. B. Vankov; J. Skiba-Szymanska; M. S. Skolnick; P. Senellart; A. Lemaitre; A. I. Tartakovskii

    2009-01-15

    Nuclear spin polarization dynamics are measured in optically pumped individual GaAs/AlGaAs interface quantum dots by detecting the time-dependence of the Overhauser shift in photoluminescence (PL) spectra. Long nuclear polarization decay times of ~ 1 minute have been found indicating inefficient nuclear spin diffusion from the GaAs dot into the surrounding AlGaAs matrix in externally applied magnetic field. A spin diffusion coefficient two orders lower than that previously found in bulk GaAs is deduced.

  14. Control of single spin in Markovian environment

    E-print Network

    Yuan, Haidong

    In this article we study the control of single spin in Markovian environment. Given an initial state, we compute all the possible states to which the spin can be driven at arbitrary time, under the assumption that fast ...

  15. Repeated measurements and nuclear spin polarization

    E-print Network

    Lian-Ao Wu

    2010-08-11

    We study repeated (noncontinuous) measurements on the electron spin in a quantum dot and find that the measurement technique may lead to a different met$ or mechanism to realize nuclear spin polarization. While it may be used in any case, the method is aimed at the further polarization, providing that nuclear spins have been polarized by the existent electrical or optical methods. The feasibility of the method is analyzed. The existing techniques in electron spin measurements are applicable to this scheme. The repeated measurements \\emph{deform} the structures of the nuclear wave function and can also serve as $\\emph{gates}$ to manipulate nuclear spins.

  16. Single Spin Measurement using Single Electron Transistors to Probe Two Electron Systems

    E-print Network

    B. E. Kane; N. S. McAlpine; A. S. Dzurak; R. G. Clark; G. J. Milburn; He Bi Sun; Howard Wiseman

    1999-06-17

    We present a method for measuring single spins embedded in a solid by probing two electron systems with a single electron transistor (SET). Restrictions imposed by the Pauli Principle on allowed two electron states mean that the spin state of such systems has a profound impact on the orbital states (positions) of the electrons, a parameter which SET's are extremely well suited to measure. We focus on a particular system capable of being fabricated with current technology: a Te double donor in Si adjacent to a Si/SiO2 interface and lying directly beneath the SET island electrode, and we outline a measurement strategy capable of resolving single electron and nuclear spins in this system. We discuss the limitations of the measurement imposed by spin scattering arising from fluctuations emanating from the SET and from lattice phonons. We conclude that measurement of single spins, a necessary requirement for several proposed quantum computer architectures, is feasible in Si using this strategy.

  17. Submillisecond hyperpolarization of nuclear spins in silicon.

    PubMed

    Hoehne, Felix; Dreher, Lukas; Franke, David P; Stutzmann, Martin; Vlasenko, Leonid S; Itoh, Kohei M; Brandt, Martin S

    2015-03-20

    In this Letter, we devise a fast and effective nuclear spin hyperpolarization scheme, which is, in principle, magnetic field independent. We use this scheme to experimentally demonstrate polarizations of up to 66% for phosphorus donor nuclear spins in bulk silicon, which are created within less than 100???s in a magnetic field of 0.35 T at a temperature of 5 K. The polarization scheme is based on a spin-dependent recombination process via weakly coupled spin pairs, for which the recombination time constant strongly depends on the relative orientation of the two spins. We further use this scheme to measure the nuclear spin relaxation time and find a value of ?100??ms under illumination, in good agreement with the value calculated for nuclear spin flips induced by repeated ionization and deionization processes. PMID:25839308

  18. Electrical control of single hole spins in nanowire quantum dots

    NASA Astrophysics Data System (ADS)

    Pribiag, V. S.; Nadj-Perge, S.; Frolov, S. M.; van den Berg, J. W. G.; van Weperen, I.; Plissard, S. R.; Bakkers, E. P. A. M.; Kouwenhoven, L. P.

    2013-03-01

    The development of viable quantum computation devices will require the ability to preserve the coherence of quantum bits (qubits). Single electron spins in semiconductor quantum dots are a versatile platform for quantum information processing, but controlling decoherence remains a considerable challenge. Hole spins in III-V semiconductors have unique properties, such as a strong spin-orbit interaction and weak coupling to nuclear spins, and therefore, have the potential for enhanced spin control and longer coherence times. A weaker hyperfine interaction has previously been reported in self-assembled quantum dots using quantum optics techniques, but the development of hole-spin-based electronic devices in conventional III-V heterostructures has been limited by fabrication challenges. Here, we show that gate-tunable hole quantum dots can be formed in InSb nanowires and used to demonstrate Pauli spin blockade and electrical control of single hole spins. The devices are fully tunable between hole and electron quantum dots, which allows the hyperfine interaction strengths, g-factors and spin blockade anisotropies to be compared directly in the two regimes.

  19. Spin effects in single-electron transistors

    E-print Network

    Granger, Ghislain

    2005-01-01

    Basic electron transport phenomena observed in single-electron transistors (SETs) are introduced, such as Coulomb-blockade diamonds, inelastic cotunneling thresholds, the spin-1/2 Kondo effect, and Fano interference. With ...

  20. Nuclear spin noise in NMR revisited

    E-print Network

    Ferrand, Guillaume; Luong, Michel; Desvaux, Hervé

    2015-01-01

    The theoretical shapes of nuclear spin-noise spectra in NMR are derived by considering a receiver circuit with finite, preamplifier input impedance and a transmission line between the preamplifier and the probe. Using this model, it becomes possible to reproduce all observed experimental features: variation of the NMR resonance linewidth as a function of the transmission line phase, nuclear spin-noise signals appearing as a "bump" or as a "dip" superimposed on the average electronic noise level even for a spin system and probe at the same temperature, pure in-phase Lorentzian spin-noise signals exhibiting non-vanishing frequency shifts. Extensive comparison to experimental measurements validate the model predictions, and define the conditions for obtaining pure in-phase Lorentzian-shape nuclear spin noise with a vanishing frequency shift, in other words, the conditions for simultaneously obtaining the Spin-Noise and Frequency-Shift Tuning Optima.

  1. Single spin optically detected magnetic resonance with 60-90 GHz (E-band) microwave resonators

    NASA Astrophysics Data System (ADS)

    Aslam, Nabeel; Pfender, Matthias; Stöhr, Rainer; Neumann, Philipp; Scheffler, Marc; Sumiya, Hitoshi; Abe, Hiroshi; Onoda, Shinobu; Ohshima, Takeshi; Isoya, Junichi; Wrachtrup, Jörg

    2015-06-01

    Magnetic resonance with ensembles of electron spins is commonly performed around 10 GHz, but also at frequencies above 240 GHz and in corresponding magnetic fields of over 9 T. However, experiments with single electron and nuclear spins so far only reach into frequency ranges of several 10 GHz, where existing coplanar waveguide structures for microwave (MW) delivery are compatible with single spin readout techniques (e.g., electrical or optical readout). Here, we explore the frequency range up to 90 GHz, with magnetic fields of up to ?3 T for single spin magnetic resonance in conjunction with optical spin readout. To this end, we develop MW resonators with optical single spin access. In our case, rectangular 60-90 GHz (E-band) waveguides guarantee low-loss supply of microwaves to the resonators. Three dimensional cavities, as well as coplanar waveguide resonators, enhance MW fields by spatial and spectral confinement with a MW efficiency of 1 . 36 mT / ?{ W } . We utilize single nitrogen vacancy (NV) centers as hosts for optically accessible spins and show that their properties regarding optical spin readout known from smaller fields (<0.65 T) are retained up to fields of 3 T. In addition, we demonstrate coherent control of single nuclear spins under these conditions. Furthermore, our results extend the applicable magnetic field range of a single spin magnetic field sensor. Regarding spin based quantum registers, high fields lead to a purer product basis of electron and nuclear spins, which promises improved spin lifetimes. For example, during continuous single-shot readout, the 14N nuclear spin shows second-long longitudinal relaxation times.

  2. Conversion of Nuclear Spin Isomers of Ethylene

    NASA Astrophysics Data System (ADS)

    Chapovsky, P. L.; Zhivonitko, V. V.; Koptyug, I. V.

    2013-10-01

    A theoretical model of the nuclear spin isomer conversion in C2H4 induced by the intramolecular spin-spin interaction between hydrogen nuclei has been developed. In the ground electronic state, C2H4 has four nuclear spin isomers in contrast to two isomers in the molecules studied so far in this field of research. At the gas pressure of 1 Torr, the rate of conversion between isomers with the nuclear spin symmetries B1u and B2u was found to be 5.2 - 10-4 s-1, which coincides within experimental uncertainties with the rate recently measured by Sun et al. ( Science 2005, 310, 1938 ). It was determined that at low gas pressures the conversion is induced mainly by the mixing of only one pair of rotational states. The calculated pressure dependence of the conversion rate predicts that conversion slows down with increasing pressure at pressures higher than 300 Torr.

  3. Electrically controlling single spin qubits in a continuous microwave field

    E-print Network

    Arne Laucht; Juha T. Muhonen; Fahd A. Mohiyaddin; Rachpon Kalra; Juan P. Dehollain; Solomon Freer; Fay E. Hudson; Menno Veldhorst; Rajib Rahman; Gerhard Klimeck; Kohei M. Itoh; David N. Jamieson; Jeffrey C. McCallum; Andrew S. Dzurak; Andrea Morello

    2015-03-20

    Large-scale quantum computers must be built upon quantum bits that are both highly coherent and locally controllable. We demonstrate the quantum control of the electron and the nuclear spin of a single 31P atom in silicon, using a continuous microwave magnetic field together with nanoscale electrostatic gates. The qubits are tuned into resonance with the microwave field by a local change in electric field, which induces a Stark shift of the qubit energies. This method, known as A-gate control, preserves the excellent coherence times and gate fidelities of isolated spins, and can be extended to arbitrarily many qubits without requiring multiple microwave sources.

  4. Single-proton spin detection by diamond magnetometry.

    PubMed

    Loretz, M; Rosskopf, T; Boss, J M; Pezzagna, S; Meijer, J; Degen, C L

    2014-10-16

    Extending magnetic resonance imaging to the atomic scale has been a long-standing aspiration, driven by the prospect of directly mapping atomic positions in molecules with three-dimensional spatial resolution. We report detection of individual, isolated proton spins by a nitrogen-vacancy (NV) center in a diamond chip covered by an inorganic salt. The single-proton identity was confirmed by the Zeeman effect and by a quantum coherent rotation of the weakly coupled nuclear spin. Using the hyperfine field of the NV center as an imaging gradient, we determined proton-NV distances of less than 1 nm. PMID:25323696

  5. Room temperature entanglement between distant single spins in diamond

    E-print Network

    Florian Dolde; Ingmar Jakobi; Boris Naydenov; Nan Zhao; Sebastien Pezzagna; Christina Trautmann; Jan Meijer; Philipp Neumann; Fedor Jelezko; Jörg Wrachtrup

    2012-12-12

    Entanglement is the central yet fleeting phenomena of quantum physics. Once being considered a peculiar counter-intuitive property of quantum theory it has developed into the most central element of quantum technology providing speed up to quantum computers, a path towards long distance quantum cryptography and increased sensitivity in quantum metrology. Consequently, there have been a number of experimental demonstration of entanglement between photons, atoms, ions as well as solid state systems like spins or quantum dots, superconducting circuits and macroscopic diamond. Here we experimentally demonstrate entanglement between two engineered single solid state spin quantum bits (qubits) at ambient conditions. Photon emission of defect pairs reveals ground state spin correlation. Entanglement (fidelity = 0.67 \\pm 0.04) is proven by quantum state tomography. Moreover, the lifetime of electron spin entanglement is extended to ms by entanglement swapping to nuclear spins, demonstrating nuclear spin entanglement over a length scale of 25 nm. The experiments mark an important step towards a scalable room temperature quantum device being of potential use in quantum information processing as well as metrology.

  6. Population and coherence transfer in half-integer quadrupolar spin systems induced by simultaneous rapid passages of the satellite transitions: A static and spinning single crystal nuclear magnetic resonance study

    NASA Astrophysics Data System (ADS)

    Schäfer, Hartmut; Iuga, Dinu; Verhagen, Rieko; Kentgens, Arno P. M.

    2001-02-01

    We have recently shown that utilizing double frequency sweeps (DFSs) instead of pulses can lead to increased efficiencies in population and coherence transfer in half-integer quadrupolar spin systems. Cosine modulation of the carrier amplitude corresponds to the simultaneous irradiation of two frequencies symmetrically around the rf-carrier frequency. Convergent or divergent DFSs can be generated by appropriate time-dependent cosine modulation of the rf field. Population and coherence transfer induced by sweeping the modulation frequency through the quadrupolar satellite transitions is investigated in detail. The time dependence of such passages determines the adiabaticity of the transfer processes. Insight into the involved spin dynamics is of utmost importance in the design and optimization of experiments based on amplitude modulation, such as DFS enhanced multiple-quantum magic angle spanning, where multiple to single-quantum conversion is performed by a DFS. Vega and co-workers have provided a theoretical basis of adiabatic coherence transfer in spin-3/2 systems induced by the combined action of simple time independent cosine amplitude modulation (CAM) of the rf field and sample spinning [Madhu et al., J. Chem. Phys. 112, 2377 (2000)]. In our report we will extend this theory to DFS induced adiabatic transfer phenomena in spin-3/2 and spin-5/2 systems. A fully analytical description will be presented covering the whole adiabaticity range resulting in an accurate description of actual experiments. In this context it will be shown that both population and coherence transfer are governed by the same principles and one unique adiabaticity parameter for each pair of spectral satellites. The transfer phenomena derived for spin-3/2 systems will be studied and quantified experimentally for 23Na in a single crystal of NaNO3. In a static and spinning sample the combination with DFS and CAM irradiation will be studied showing the equivalence of the transfer in all these situations. Further we will demonstrate the greater flexibility of a DFS compared to a CAM pulse to manipulate the adiabaticity and thus to maximize the transfer efficiency. Finally, the 27Al resonance in an ?-Al2O3 single crystal will be inspected to demonstrate that the efficiency of DFS-induced population and coherence transfer in spin-5/2 systems depends on the direction of the DFS.

  7. Single-Spin Asymmetries and Transversity in QCD

    SciTech Connect

    Brodsky, S.J.; /SLAC

    2005-12-14

    Initial- and final-state interactions from gluon exchange, normally neglected in the parton model, have a profound effect in QCD hard-scattering reactions, leading to leading-twist single-spin asymmetries, diffractive deep inelastic scattering, diffractive hard hadronic reactions, as well as nuclear shadowing and antishadowing-leading-twist physics not incorporated in the light-front wavefunctions of the target computed in isolation. The physics of such processes thus require the understanding of QCD at the amplitude level; in particular, the physics of spin requires an understanding of the phase structure of final-state and initial-state interactions, as well as the structure of the basic wavefunctions of hadrons themselves. I also discuss transversity in exclusive channels, including how one can use single-spin asymmetries to determine the relative phases of the timelike baryon form factors, as well as the anomalous physics of the normal-normal spin-spin correlation observed in large-angle proton-proton elastic scattering. As an illustration of the utility of light-front wavefunctions, the transversity distribution of a single electron is computed, as defined from its two-particle QED quantum fluctuations.

  8. Nuclear spin conversion in diatomic molecules

    SciTech Connect

    Il'ichev, L. V., E-mail: leonid@iae.nsk.su; Shalagin, A. M. [Russian Academy of Sciences, Institute of Automation and Electrometry, Siberian Branch (Russian Federation)] [Russian Academy of Sciences, Institute of Automation and Electrometry, Siberian Branch (Russian Federation)

    2013-07-15

    A mechanism of the internal interaction in dimers that mixes different nuclear spin modifications has been proposed. It has been shown that the intramolecular current associated with transitions between electronic terms of different parities can generate different magnetic fields on nuclei, leading to transitions between spin modifications and to the corresponding changes in rotational states. In the framework of the known quantum relaxation process, this interaction initiates irreversible conversion of nuclear spin modifications. The estimated conversion rate for nitrogen at atmospheric pressure is quite high (10{sup -3}-10{sup -5} s{sup -1})

  9. Quantum registers based on single NV + n 13C centers in diamond: I. The spin Hamiltonian method

    Microsoft Academic Search

    A. P. Nizovtsev; S. Ya. Kilin; V. A. Pushkarchuk; A. L. Pushkarchuk; S. A. Kuten

    2010-01-01

    Details of the application of the spin Hamiltonian method for studying spin characteristics of a quantum register that includes an electron spin S = 1 of a single NV center in the ground electronic state and nuclear spins I = 1\\/2 of several isotopic atoms 13C located at different lattice sites near the vacancy of the NV center. Two methods

  10. Nuclear-spin noise and spontaneous emission

    NASA Astrophysics Data System (ADS)

    Sleator, Tycho; Hahn, Erwin L.; Hilbert, Claude; Clarke, John

    1987-08-01

    The spontaneous emission from nuclear spins has been observed at liquid-4He temperatures. The spins, 35Cl nuclei, are placed in the inductor of a tuned LCR circuit coupled to a dc superconducting quantum interference device used as a radio-frequency amplifier. When the spins are saturated and have zero polarization, the emission is observed at the nuclear quadrupole Larmor frequency as a bump in the spectral density of the Nyquist noise current in the tuned circuit. This bump arises from the temperature-independent fluctuations in the transverse component of the nuclear magnetization. When the spins are in thermal equilibrium, on the other hand, a dip in the spectral density of the current noise is observed, arising from an induced absorption of noise power from the circuit at the Larmor frequency. The standard circuit-coupled Bloch's equation, modified to take into account radiation damping and transverse spin fluctuations, is consistent with the predictions of the Nyquist theorem and the Einstein equation for spontaneous emission. A spin-pendulum model for spin noise is described. The signal-to-noise ratio obtainable in a spin-noise measurement is discussed.

  11. Coherent manipulation of nuclear spins using spin injection from a half-metallic spin source

    NASA Astrophysics Data System (ADS)

    Uemura, Tetsuya; Akiho, Takafumi; Ebina, Yuya; Yamamoto, Masafumi

    2015-04-01

    We have developed a nuclear magnetic resonance (NMR) system that uses spin injection from a highly polarized spin source. Efficient spin injection into GaAs from a half-metallic spin source of Mn-rich C o2MnSi enabled an efficient dynamic nuclear polarization of Ga and As nuclei in GaAs and a sensitive detection of NMR signals. Moreover, coherent control of nuclear spins, or the Rabi oscillation between two quantum levels formed at Ga nuclei, induced by a pulsed NMR has been demonstrated at a relatively low magnetic field of ˜0.1 T. This provides a novel all-electrical solid-state NMR system with the high spatial resolution and high sensitivity needed to implement scalable nuclear-spin-based qubits.

  12. Neutron single target spin asymmetries in SIDIS

    SciTech Connect

    Evaristo Cisbani

    2010-04-01

    The experiment E06-010 in Hall A at Jefferson Lab took data between November 2008 and February 2009 to directly measure, for the first time, the pion (and kaon) single "neutron" target-spin asymmetry (SSA) in semi-inclusive DIS from a polarized 3He target. Collins, Sivers (and Pretzelosity) neutron asymmetries are going to be extracted from the measured SSA. Details of the experiment are described together with the preliminary results of the ongoing analysis. Near future Hall A experiments on transverse nucleon spin structure are shorty reviewed.

  13. The spin-temperature theory of dynamic nuclear polarization and nuclear spin-lattice relaxation

    NASA Technical Reports Server (NTRS)

    Byvik, C. E.; Wollan, D. S.

    1974-01-01

    A detailed derivation of the equations governing dynamic nuclear polarization (DNP) and nuclear spin lattice relaxation by use of the spin temperature theory has been carried to second order in a perturbation expansion of the density matrix. Nuclear spin diffusion in the rapid diffusion limit and the effects of the coupling of the electron dipole-dipole reservoir (EDDR) with the nuclear spins are incorporated. The complete expression for the dynamic nuclear polarization has been derived and then examined in detail for the limit of well resolved solid effect transitions. Exactly at the solid effect transition peaks, the conventional solid-effect DNP results are obtained, but with EDDR effects on the nuclear relaxation and DNP leakage factor included. Explicit EDDR contributions to DNP are discussed, and a new DNP effect is predicted.

  14. Dynamics of a mesoscopic nuclear spin ensemble interacting with an optically driven electron spin

    NASA Astrophysics Data System (ADS)

    Stanley, M. J.; Matthiesen, C.; Hansom, J.; Le Gall, C.; Schulte, C. H. H.; Clarke, E.; Atatüre, M.

    2014-11-01

    The ability to discriminate between simultaneously occurring noise sources in the local environment of semiconductor InGaAs quantum dots, such as electric and magnetic field fluctuations, is key to understanding their respective dynamics and their effect on quantum dot coherence properties. We present a discriminatory approach to all-optical sensing based on two-color resonance fluorescence of a quantum dot charged with a single electron. Our measurements show that local magnetic field fluctuations due to nuclear spins in the absence of an external magnetic field are described by two correlation times, both in the microsecond regime. The nuclear spin bath dynamics show a strong dependence on the strength of resonant probing, with correlation times increasing by a factor of 4 as the optical transition is saturated. We interpret the behavior as motional averaging of both the Knight field of the resident electron spin and the hyperfine-mediated nuclear spin-spin interaction due to optically induced electron spin flips.

  15. Coherent, Mechanical Control of a Single Electronic Spin Sungkun Hong,,

    E-print Network

    Walsworth, Ronald L.

    Coherent, Mechanical Control of a Single Electronic Spin Sungkun Hong,, Michael S. Grinolds coherent quantum control of a single spin driven by the motion of a mechanical resonator. The motion of a mechanical resonator is magnetically coupled to the electronic spin of a single nitrogen-vacancy center

  16. Measuring mechanical motion with a single spin

    E-print Network

    S. D. Bennett; S. Kolkowitz; Q. P. Unterreithmeier; P. Rabl; A. C. Bleszynski Jayich; J. G. E. Harris; M. D. Lukin

    2012-05-30

    We study theoretically the measurement of a mechanical oscillator using a single two level system as a detector. In a recent experiment, we used a single electronic spin associated with a nitrogen vacancy center in diamond to probe the thermal motion of a magnetized cantilever at room temperature {Kolkowitz et al., Science 335, 1603 (2012)}. Here, we present a detailed analysis of the sensitivity limits of this technique, as well as the possibility to measure the zero point motion of the oscillator. Further, we discuss the issue of measurement backaction in sequential measurements and find that although backaction heating can occur, it does not prohibit the detection of zero point motion. Throughout the paper we focus on the experimental implementation of a nitrogen vacancy center coupled to a magnetic cantilever; however, our results are applicable to a wide class of spin-oscillator systems. Implications for preparation of nonclassical states of a mechanical oscillator are also discussed.

  17. Single Spin Asymmetries in the BRAHMS Experiment

    E-print Network

    F. Videbaek; for the BRAHMS collaboration

    2006-01-04

    The BRAHMS experiment at RHIC has measured the transverse single spin asymmetries in polarized pp induced pion production at RHIC. The results from the RHIC run-5 shows a significant asymmetry for pi+ and pi- at moderate xF. The trend of the data is in agreement with lower energy results while the absolute values are surprisingly large. The pT dependence is approximately inversely propotional to pT in agreement with the pQCD expectations.

  18. Resolving Remoter Nuclear Spins in a Noisy Bath by Dynamical Decoupling Design

    E-print Network

    Wenchao Ma; Fazhan Shi; Kebiao Xu; Pengfei Wang; Xiangkun Xu; Xing Rong; Chenyong Ju; Chang-Kui Duan; Nan Zhao; Jiangfeng Du

    2015-06-16

    We experimentally resolve several weakly coupled nuclear spins in diamond using a series of novelly designed dynamical decoupling controls. Some nuclear spin signals, hidden by decoherence under ordinary dynamical decoupling controls, are shifted forward in time domain to the coherence time range and thus rescued from the fate of being submerged by the noisy spin bath. In this way, more and remoter single nuclear spins are resolved. Additionally, the field of detection can be continuously tuned on sub-nanoscale. This method extends the capacity of nanoscale magnetometry and may be applicable in other systems for high-resolution noise spectroscopy.

  19. Nuclear spin effects in optical lattice clocks

    SciTech Connect

    Boyd, Martin M.; Zelevinsky, Tanya; Ludlow, Andrew D.; Blatt, Sebastian; Zanon-Willette, Thomas; Foreman, Seth M.; Ye Jun [JILA, National Institute of Standards and Technology and University of Colorado, Department of Physics, University of Colorado, Boulder, Colorado 80309-0440 (United States)

    2007-08-15

    We present a detailed experimental and theoretical study of the effect of nuclear spin on the performance of optical lattice clocks. With a state-mixing theory including spin-orbit and hyperfine interactions, we describe the origin of the {sup 1}S{sub 0}-{sup 3}P{sub 0} clock transition and the differential g factor between the two clock states for alkaline-earth-metal(-like) atoms, using {sup 87}Sr as an example. Clock frequency shifts due to magnetic and optical fields are discussed with an emphasis on those relating to nuclear structure. An experimental determination of the differential g factor in {sup 87}Sr is performed and is in good agreement with theory. The magnitude of the tensor light shift on the clock states is also explored experimentally. State specific measurements with controlled nuclear spin polarization are discussed as a method to reduce the nuclear spin-related systematic effects to below 10{sup -17} in lattice clocks.

  20. Nuclear spin cooling using Overhauser field selective coherent population trapping

    E-print Network

    Mena Issler; Eric Kessler; Geza Giedke; Susanne Yelin; Ignacio Cirac; Mikhail Lukin; Atac Imamoglu

    2010-08-20

    Hyperfine interactions with a nuclear spin environment fundamentally limit the coherence properties of confined electron spins in the solid-state. Here, we show that a quantum interference effect in optical absorption from two electronic spin states of a solid-state emitter can be used to prepare the surrounding environment of nuclear spins in well-defined states, thereby suppressing electronic spin dephasing. The evolution of the coupled electron-nuclei system into a coherent population trapping state by optical excitation induced nuclear spin diffusion can be described in terms of Levy flights, in close analogy with sub-recoil laser cooling of atoms. The large difference in electronic and nuclear time scales simultaneously allow for a measurement of the magnetic field produced by nuclear spins, making it possible to turn the lasers that cause the anomalous spin diffusion process off when the strength of the resonance fluorescence reveals that the nuclear spins are in the desired narrow state.

  1. Radio Frequency Scanning Tunneling Spectroscopy for Single-Molecule Spin Resonance

    NASA Astrophysics Data System (ADS)

    Müllegger, Stefan; Tebi, Stefano; Das, Amal K.; Schöfberger, Wolfgang; Faschinger, Felix; Koch, Reinhold

    2014-09-01

    We probe nuclear and electron spins in a single molecule even beyond the electromagnetic dipole selection rules, at readily accessible magnetic fields (few mT) and temperatures (5 K) by resonant radio-frequency current from a scanning tunneling microscope. We achieve subnanometer spatial resolution combined with single-spin sensitivity, representing a 10 orders of magnitude improvement compared to existing magnetic resonance techniques. We demonstrate the successful resonant spectroscopy of the complete manifold of nuclear and electronic magnetic transitions of up to ?Iz=±3 and ?Jz=±12 of single quantum spins in a single molecule. Our method of resonant radio-frequency scanning tunneling spectroscopy offers, atom-by-atom, unprecedented analytical power and spin control with an impact on diverse fields of nanoscience and nanotechnology.

  2. Radio frequency scanning tunneling spectroscopy for single-molecule spin resonance.

    PubMed

    Müllegger, Stefan; Tebi, Stefano; Das, Amal K; Schöfberger, Wolfgang; Faschinger, Felix; Koch, Reinhold

    2014-09-26

    We probe nuclear and electron spins in a single molecule even beyond the electromagnetic dipole selection rules, at readily accessible magnetic fields (few mT) and temperatures (5 K) by resonant radio-frequency current from a scanning tunneling microscope. We achieve subnanometer spatial resolution combined with single-spin sensitivity, representing a 10 orders of magnitude improvement compared to existing magnetic resonance techniques. We demonstrate the successful resonant spectroscopy of the complete manifold of nuclear and electronic magnetic transitions of up to ?I(z)=±3 and ?J(z)=±12 of single quantum spins in a single molecule. Our method of resonant radio-frequency scanning tunneling spectroscopy offers, atom-by-atom, unprecedented analytical power and spin control with an impact on diverse fields of nanoscience and nanotechnology. PMID:25302884

  3. Measuring mechanical motion with a single spin

    NASA Astrophysics Data System (ADS)

    Bennett, S. D.; Kolkowitz, S.; Unterreithmeier, Q. P.; Rabl, P.; Bleszynski Jayich, A. C.; Harris, J. G. E.; Lukin, M. D.

    2012-12-01

    We study theoretically the measurement of a mechanical oscillator using a single two-level system as a detector. In a recent experiment, we used a single electronic spin associated with a nitrogen-vacancy center in diamond to probe the thermal motion of a magnetized cantilever at room temperature (Kolkowitz et al 2012 Science 335 1603). Here, we present a detailed analysis of the sensitivity limits of this technique, as well as the possibility to measure the zero-point motion of the oscillator. Further, we discuss the issue of measurement backaction in sequential measurements and find that although backaction heating can occur, it does not prohibit the detection of zero-point motion. Throughout the paper, we focus on the experimental implementation of a nitrogen-vacancy center coupled to a magnetic cantilever; however, our results are applicable to a wide class of spin-oscillator systems. The implications for the preparation of nonclassical states of a mechanical oscillator are also discussed.

  4. NUCLEAR SPIN ISOSPIN RESPONSES FOR LOW-ENERGY NEUTRINOS

    E-print Network

    Washington at Seattle, University of

    NUCLEAR SPIN ISOSPIN RESPONSES FOR LOW-ENERGY NEUTRINOS Hiroyasu EJIRI Nuclear Physics Laboratory@rcnp.osaka-u.ac.jp (H. Ejiri). Physics Reports 338 (2000) 265}351 Nuclear spin isospin responses for low-energy Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka, 567 Japan. E-mail address: ejiri

  5. $^{29}$Si nuclear spins as a resource for donor spin qubits in silicon

    E-print Network

    Gary Wolfowicz; Pierre-Andre Mortemousque; Roland Guichard; Stephanie Simmons; Mike L. W. Thewalt; Kohei M. Itoh; John J. L. Morton

    2015-05-08

    Nuclear spin registers in the vicinity of electron spins in solid state systems offer a powerful resource to address the challenge of scalability in quantum architectures. We investigate here the properties of $^{29}$Si nuclear spins surrounding donor atoms in silicon, and consider the use of such spins, combined with the donor nuclear spin, as a quantum register coupled to the donor electron spin. We find the coherence of the nearby $^{29}$Si nuclear spins is effectively protected by the presence of the donor electron spin, leading to coherence times in the second timescale - over two orders of magnitude greater than the coherence times in bulk silicon. We theoretically investigate the use of such a register for quantum error correction, including methods to protect nuclear spins from the ionisation/neutralisation of the donor, which is necessary for the re-initialisation of the ancillae qubits. This provides a route for multi-round quantum error correction using donors in silicon.

  6. Atomic-scale nuclear spin imaging using quantum-assisted sensors in diamond

    E-print Network

    Ashok Ajoy; Ulf Bissbort; Mikhail D. Lukin; Ronald L. Walsworth; Paola Cappellaro

    2014-07-11

    Nuclear spin imaging at the atomic level is essential for the understanding of fundamental biological phenomena and for applications such as drug discovery. The advent of novel nano-scale sensors has given hope of achieving the long-standing goal of single-protein, high spatial-resolution structure determination in their natural environment and ambient conditions. In particular, quantum sensors based on the spin-dependent photoluminescence of Nitrogen Vacancy (NV) centers in diamond have recently been used to detect nanoscale ensembles of external nuclear spins. While NV sensitivity is approaching single-spin levels, extracting relevant information from a very complex structure is a further challenge, since it requires not only the ability to sense the magnetic field of an isolated nuclear spin, but also to achieve atomic-scale spatial resolution. Here we propose a method that, by exploiting the coupling of the NV center to an intrinsic quantum memory associated with the Nitrogen nuclear spin, can reach a tenfold improvement in spatial resolution, down to atomic scales. The spatial resolution enhancement is achieved through coherent control of the sensor spin, which creates a dynamic frequency filter selecting only a few nuclear spins at a time. We propose and analyze a protocol that would allow not only sensing individual spins in a complex biomolecule, but also unraveling couplings among them, thus elucidating local characteristics of the molecule structure.

  7. Atomic-Scale Nuclear Spin Imaging Using Quantum-Assisted Sensors in Diamond

    NASA Astrophysics Data System (ADS)

    Ajoy, A.; Bissbort, U.; Lukin, M. D.; Walsworth, R. L.; Cappellaro, P.

    2015-01-01

    Nuclear spin imaging at the atomic level is essential for the understanding of fundamental biological phenomena and for applications such as drug discovery. The advent of novel nanoscale sensors promises to achieve the long-standing goal of single-protein, high spatial-resolution structure determination under ambient conditions. In particular, quantum sensors based on the spin-dependent photoluminescence of nitrogen-vacancy (NV) centers in diamond have recently been used to detect nanoscale ensembles of external nuclear spins. While NV sensitivity is approaching single-spin levels, extracting relevant information from a very complex structure is a further challenge since it requires not only the ability to sense the magnetic field of an isolated nuclear spin but also to achieve atomic-scale spatial resolution. Here, we propose a method that, by exploiting the coupling of the NV center to an intrinsic quantum memory associated with the nitrogen nuclear spin, can reach a tenfold improvement in spatial resolution, down to atomic scales. The spatial resolution enhancement is achieved through coherent control of the sensor spin, which creates a dynamic frequency filter selecting only a few nuclear spins at a time. We propose and analyze a protocol that would allow not only sensing individual spins in a complex biomolecule, but also unraveling couplings among them, thus elucidating local characteristics of the molecule structure.

  8. Recursive polarization of nuclear spins in diamond at arbitrary magnetic field

    NASA Astrophysics Data System (ADS)

    Pagliero, Daniela; Laraoui, Abdelghani; Henshaw, Jacob; Meriles, Carlos

    2015-03-01

    We introduce an alternate route to dynamically polarize the nuclear spin host of nitrogen-vacancy (NV) centers in diamond. Our approach articulates optical, microwave and radio-frequency pulses to recursively transfer spin polarization from the NV electronic spin. Using two complementary variants of the same underlying principle, we demonstrate nitrogen nuclear spin initialization approaching 80% at room temperature both in ensemble and single NV centers. Unlike existing schemes, our approach does not rely on level anti-crossings and is thus applicable at arbitrary magnetic fields. This versatility should prove useful in applications ranging from nanoscale metrology to sensitivity-enhanced NMR.

  9. Recursive polarization of nuclear spins in diamond at arbitrary magnetic fields

    NASA Astrophysics Data System (ADS)

    Pagliero, Daniela; Laraoui, Abdelghani; Henshaw, Jacob D.; Meriles, Carlos A.

    2014-12-01

    We introduce an alternate route to dynamically polarize the nuclear spin host of nitrogen-vacancy (NV) centers in diamond. Our approach articulates optical, microwave, and radio-frequency pulses to recursively transfer spin polarization from the NV electronic spin. Using two complementary variants of the same underlying principle, we demonstrate nitrogen nuclear spin initialization approaching 80% at room temperature both in ensemble and single NV centers. Unlike existing schemes, our approach does not rely on level anti-crossings and is thus applicable at arbitrary magnetic fields. This versatility should prove useful in applications ranging from nanoscale metrology to sensitivity-enhanced NMR.

  10. Recursive polarization of nuclear spins in diamond at arbitrary magnetic fields

    E-print Network

    Daniela Pagliero; Abdelghani Laraoui; Jacob D. Henshaw; Carlos A. Meriles

    2014-12-17

    We introduce an alternate route to dynamically polarize the nuclear spin host of nitrogen-vacancy (NV) centers in diamond. Our approach articulates optical, microwave and radio-frequency pulses to recursively transfer spin polarization from the NV electronic spin. Using two complementary variants of the same underlying principle, we demonstrate nitrogen nuclear spin initialization approaching 80% at room temperature both in ensemble and single NV centers. Unlike existing schemes, our approach does not rely on level anti-crossings and is thus applicable at arbitrary magnetic fields. This versatility should prove useful in applications ranging from nanoscale metrology to sensitivity-enhanced NMR.

  11. Engineering near-infrared single-photon emitters with optically active spins in ultrapure silicon carbide.

    PubMed

    Fuchs, F; Stender, B; Trupke, M; Simin, D; Pflaum, J; Dyakonov, V; Astakhov, G V

    2015-01-01

    Vacancy-related centres in silicon carbide are attracting growing attention because of their appealing optical and spin properties. These atomic-scale defects can be created using electron or neutron irradiation; however, their precise engineering has not been demonstrated yet. Here, silicon vacancies are generated in a nuclear reactor and their density is controlled over eight orders of magnitude within an accuracy down to a single vacancy level. An isolated silicon vacancy serves as a near-infrared photostable single-photon emitter, operating even at room temperature. The vacancy spins can be manipulated using an optically detected magnetic resonance technique, and we determine the transition rates and absorption cross-section, describing the intensity-dependent photophysics of these emitters. The on-demand engineering of optically active spins in technologically friendly materials is a crucial step toward implementation of both maser amplifiers, requiring high-density spin ensembles, and qubits based on single spins. PMID:26151881

  12. Harnessing the GaAs quantum dot nuclear spin bath for quantum control

    E-print Network

    Hugo Ribeiro; J. R. Petta; Guido Burkard

    2011-12-20

    We theoretically demonstrate that nuclear spins can be harnessed to coherently control two-electron spin states in a double quantum dot. Hyperfine interactions lead to an avoided crossing between the spin singlet state and the ms = +1 triplet state, T_+ . We show that a coherent superposition of singlet and triplet states can be achieved using finite-time Landau-Zener-St\\"uckelberg interferometry. In this system the coherent rotation rate is set by the Zeeman energy, resulting in ~1 nanosecond single spin rotations. We analyze the coherence of this spin qubit by considering the coupling to the nuclear spin bath and show that T_2^* ~ 16 ns, in good agreement with experimental data. Our analysis further demonstrates that efficient single qubit and two qubit control can be achieved using Landau-Zener-St\\"uckelberg interferometry.

  13. Lévy flights in laser cooling of nuclear spins

    NASA Astrophysics Data System (ADS)

    Singh, Swati; Chu, Y.; Pick, A.; Aspect, A.; Lukin, M.; Yelin, S.

    2014-05-01

    Interaction between an electronic spin and its surrounding nuclear spin environment is a major source of decoherence in most solid-state spin qubits. We develop a phenomenological model for nuclear spin diffusion in the presence of electronic dark states. As an quantitative example, we study the diffusion in 13C nuclear spin bath of an NV- impurity in diamond. We use this model to predict that the nuclear diffusion time-scales exhibit Lévy statistics-- enabling nuclear spins to remain trapped in certain configurations for long times. We comment on observing such statistics by measuring photon scattering rates that are dependent on nuclear diffusion rates, leading to quantitative measurements of the non-equilibrium bath dynamics in such central-spin systems.

  14. Optically driven Rabi oscillations and adiabatic passage of single electron spins in diamond.

    PubMed

    Golter, D Andrew; Wang, Hailin

    2014-03-21

    Rabi oscillations and adiabatic passage of single electron spins in a diamond nitrogen vacancy center are demonstrated with two Raman-resonant optical pulses that are detuned from the respective dipole optical transitions. We show that the optical spin control is nuclear-spin selective and can be robust against rapid decoherence, including radiative decay and spectral diffusion, of the underlying optical transitions. A direct comparison between the Rabi oscillation and the adiabatic passage, along with a detailed theoretical analysis, provides significant physical insights into the connections and differences between these coherent spin processes and also elucidates the role of spectral diffusion in these processes. The optically driven coherent spin processes enable the use of nitrogen vacancy excited states to mediate coherent spin-phonon coupling, opening the door to combining optical control of both spin and mechanical degrees of freedom. PMID:24702393

  15. Single transverse-spin asymmetry in QCD

    NASA Astrophysics Data System (ADS)

    Koike, Yuji

    2014-09-01

    So far large single transverse-spin asymmetries (SSA) have been observed in many high-energy processes such as semi-inclusive deep inelastic scattering and proton-proton collisions. Since the conventional parton model and perturbative QCD can not accomodate such large SSAs, the framework for QCD hard processes had to be extended to understand the mechanism of SSA. In this extended frameworks of QCD, intrinsic transverse momentum of partons and the multi-parton (quark-gluon and pure-gluonic) correlations in the hadrons, which were absent in the conventional framework, play a crucial role to cause SSAs, and well-defined formulation of these effects has been a big challenge for QCD theorists. Study on these effects has greatly promoted our understanding on QCD dynamics and hadron structure. In this talk, I will present an overview on these theoretical activity, emphasizing the important role of the Drell-Yan process.

  16. Nuclear spin cooling using Overhauser-field selective coherent population trapping.

    PubMed

    Issler, M; Kessler, E M; Giedke, G; Yelin, S; Cirac, I; Lukin, M D; Imamoglu, A

    2010-12-31

    We show that a quantum interference effect in optical absorption from two electronic spin states of a solid-state emitter can be used to prepare the surrounding environment of nuclear spins in well-defined states, thereby suppressing electronic spin dephasing. The coupled electron-nuclei system evolves into a coherent population trapping state by optical-excitation-induced nuclear-spin diffusion for a broad range of initial optical detunings. The spectroscopic signature of this evolution where the single-electron strongly modifies its environment is a drastic broadening of the dark resonance in optical absorption experiments. The large difference in electronic and nuclear time scales allows us to verify the preparation of nuclear spins in the desired state. PMID:21231709

  17. Technical Notes Single-Sensor Identification of Spinning

    E-print Network

    Huang, Xun

    Technical Notes Single-Sensor Identification of Spinning Mode Noise from Aircraft Engine Xun Huang of aircraft. The development of high bypass ratio turbofan aircraft engines makes spinning mode noise function of the first kind K = gain of Kalman filter k = spinning mode frequency, Hz ka = axial wave number

  18. Quantum registers based on single NV + n 13 C centers in diamond: I. The spin Hamiltonian method

    Microsoft Academic Search

    A. P. Nizovtsev; S. Ya. Kilin; V. A. Pushkarchuk; A. L. Pushkarchuk; S. A. Kuten’

    2010-01-01

    Details of the application of the spin Hamiltonian method for studying spin characteristics of a quantum register that includes\\u000a an electron spin S = 1 of a single NV center in the ground electronic state and nuclear spins I = 1\\/2 of several isotopic atoms 13C located at different lattice sites near the vacancy of the NV center. Two methods

  19. Coherence and Control of Quantum Registers Based on Electronic Spin in a Nuclear Spin Bath

    E-print Network

    Hodges, Jonathan S.

    We consider a protocol for the control of few-qubit registers comprising one electronic spin embedded in a nuclear spin bath. We show how to isolate a few proximal nuclear spins from the rest of the bath and use them as ...

  20. State preparation and metrology of nitrogen nuclear spin in diamond

    E-print Network

    Bang, Kilhyun

    2012-01-01

    steady-state population of N nuclear spin can be achievepopulation back from |0, ? GS to |?1, ? with the the dynamic nuclearnuclear spin polarization at the steady state is available from the rate equations. The population

  1. Single-Spin Asymmetries in Inclusive and Exclusive Hadronic Processes

    E-print Network

    Dae Sung Hwang; Jong Hyun Kim; Seyong Kim

    2007-05-16

    We investigate the single-spin asymmetries in inclusive and exclusive processes of electron-proton scattering and electron-positron annihilation. In the decomposition of hadronic tensor, a Lorentz symmetric spin-dependent term is generally present. The existence of such a term implies single-spin asymmetries in these processes and these single-spin asymmetries for baryons can be understood in a unified manner. We argue that it is important to measure the single-spin asymmetries in both inclusive and exclusive processes for the $\\Lambda$ production at the present B-factories. This will lead to the first measurement of the structure function of the symmetric spin-dependent hadronic tensor in these processes.

  2. Landau-Zener-Stuckelberg interferometry of a single electron spin in a noisy environment

    E-print Network

    Huang, Pu; Fang, Fang; Kong, Xi; Xu, Xiangkun; Ju, Chenyong; Du, Jiangfeng

    2011-01-01

    We demonstrate quantum coherent control of a single electron spin in a NV center in diamond using the Landau-Zener-Stuckelberg interferometry at room temperature. Interference pattern is observed oscillating as a function of microwave frequency. The decays in the visibility of the interference are well explained by numerical simulation which includes the thermal fluctuations of the nuclear bath which shows that Landau-Zener-Stuckelberg interferometry can be used for probing electron spin decoherence processes.

  3. Landau-Zener-Stuckelberg interferometry of a single electron spin in a noisy environment

    E-print Network

    Pu Huang; Jingwei Zhou; Fang Fang; Xi Kong; Xiangkun Xu; Chenyong Ju; Jiangfeng Du

    2011-06-08

    We demonstrate quantum coherent control of a single electron spin in a NV center in diamond using the Landau-Zener-Stuckelberg interferometry at room temperature. Interference pattern is observed oscillating as a function of microwave frequency. The decays in the visibility of the interference are well explained by numerical simulation which includes the thermal fluctuations of the nuclear bath which shows that Landau-Zener-Stuckelberg interferometry can be used for probing electron spin decoherence processes.

  4. Nanoscale magnetic imaging of a single electron spin under ambient conditions

    NASA Astrophysics Data System (ADS)

    Grinolds, M. S.; Hong, S.; Maletinsky, P.; Luan, L.; Lukin, M. D.; Walsworth, R. L.; Yacoby, A.

    2013-04-01

    The detection of ensembles of spins under ambient conditions has revolutionized the biological, chemical and physical sciences through magnetic resonance imaging and nuclear magnetic resonance. Pushing sensing capabilities to the individual-spin level would enable unprecedented applications such as single-molecule structural imaging; however, the weak magnetic fields from single spins are undetectable by conventional far-field resonance techniques. In recent years, there has been a considerable effort to develop nanoscale scanning magnetometers, which are able to measure fewer spins by bringing the sensor in close proximity to its target. The most sensitive of these magnetometers generally require low temperatures for operation, but the ability to measure under ambient conditions (standard temperature and pressure) is critical for many imaging applications, particularly in biological systems. Here we demonstrate detection and nanoscale imaging of the magnetic field from an initialized single electron spin under ambient conditions using a scanning nitrogen-vacancy magnetometer. Real-space, quantitative magnetic-field images are obtained by deterministically scanning our nitrogen-vacancy magnetometer 50nm above a target electron spin, while measuring the local magnetic field using dynamically decoupled magnetometry protocols. We discuss how this single-spin detection enables the study of a variety of room-temperature phenomena in condensed-matter physics with an unprecedented combination of spatial resolution and spin sensitivity.

  5. Macroscopic rotation of photon polarization induced by a single spin

    NASA Astrophysics Data System (ADS)

    Arnold, Christophe; Demory, Justin; Loo, Vivien; Lemaître, Aristide; Sagnes, Isabelle; Glazov, Mikhaïl; Krebs, Olivier; Voisin, Paul; Senellart, Pascale; Lanco, Loïc

    2015-02-01

    Entangling a single spin to the polarization of a single incoming photon, generated by an external source, would open new paradigms in quantum optics such as delayed-photon entanglement, deterministic logic gates or fault-tolerant quantum computing. These perspectives rely on the possibility that a single spin induces a macroscopic rotation of a photon polarization. Such polarization rotations induced by single spins were recently observed, yet limited to a few 10?3 degrees due to poor spin–photon coupling. Here we report the enhancement by three orders of magnitude of the spin–photon interaction, using a cavity quantum electrodynamics device. A single hole spin in a semiconductor quantum dot is deterministically coupled to a micropillar cavity. The cavity-enhanced coupling between the incoming photons and the solid-state spin results in a polarization rotation by ±6° when the spin is optically initialized in the up or down state. These results open the way towards a spin-based quantum network.

  6. Macroscopic rotation of photon polarization induced by a single spin

    PubMed Central

    Arnold, Christophe; Demory, Justin; Loo, Vivien; Lemaître, Aristide; Sagnes, Isabelle; Glazov, Mikhaïl; Krebs, Olivier; Voisin, Paul; Senellart, Pascale; Lanco, Loïc

    2015-01-01

    Entangling a single spin to the polarization of a single incoming photon, generated by an external source, would open new paradigms in quantum optics such as delayed-photon entanglement, deterministic logic gates or fault-tolerant quantum computing. These perspectives rely on the possibility that a single spin induces a macroscopic rotation of a photon polarization. Such polarization rotations induced by single spins were recently observed, yet limited to a few 10?3 degrees due to poor spin–photon coupling. Here we report the enhancement by three orders of magnitude of the spin–photon interaction, using a cavity quantum electrodynamics device. A single hole spin in a semiconductor quantum dot is deterministically coupled to a micropillar cavity. The cavity-enhanced coupling between the incoming photons and the solid-state spin results in a polarization rotation by ±6° when the spin is optically initialized in the up or down state. These results open the way towards a spin-based quantum network. PMID:25687134

  7. Chemical distinction by nuclear spin optical rotation.

    PubMed

    Ikäläinen, Suvi; Romalis, Michael V; Lantto, Perttu; Vaara, Juha

    2010-10-01

    Nuclear spin optical rotation (NSOR) arising from the Faraday effect constitutes a novel, advantageous method for detection of nuclear magnetic resonance, provided that a distinction is seen between different chemical surroundings of magnetic nuclei. Efficient first-principles calculations for isolated water, ethanol, nitromethane, and urea molecules at standard laser wavelengths reveal a range of NSOR for different molecules and inequivalent nuclei, indicating the existence of an optical chemical shift. 1H results for H2O(l) are in excellent agreement with recent pioneering experiments. We also evaluate, for the same systems, the Verdet constants of Faraday rotation due to an external magnetic field. Calculations of NSOR in ethanol and a 11-cis-retinal protonated Schiff base imply an enhanced chemical distinction between chromophores at laser wavelengths approaching optical resonance. PMID:21230897

  8. Chemical Distinction by Nuclear Spin Optical Rotation

    NASA Astrophysics Data System (ADS)

    Ikäläinen, Suvi; Romalis, Michael V.; Lantto, Perttu; Vaara, Juha

    2010-10-01

    Nuclear spin optical rotation (NSOR) arising from the Faraday effect constitutes a novel, advantageous method for detection of nuclear magnetic resonance, provided that a distinction is seen between different chemical surroundings of magnetic nuclei. Efficient first-principles calculations for isolated water, ethanol, nitromethane, and urea molecules at standard laser wavelengths reveal a range of NSOR for different molecules and inequivalent nuclei, indicating the existence of an optical chemical shift. H1 results for H2O(l) are in excellent agreement with recent pioneering experiments. We also evaluate, for the same systems, the Verdet constants of Faraday rotation due to an external magnetic field. Calculations of NSOR in ethanol and a 11-cis-retinal protonated Schiff base imply an enhanced chemical distinction between chromophores at laser wavelengths approaching optical resonance.

  9. Control of coherence among the spins of a single electron and the three nearest neighbor 13C nuclei of a nitrogen-vacancy center in diamond

    NASA Astrophysics Data System (ADS)

    Shimo-Oka, T.; Kato, H.; Yamasaki, S.; Jelezko, F.; Miwa, S.; Suzuki, Y.; Mizuochi, N.

    2015-04-01

    Individual nuclear spins in diamond can be optically detected through hyperfine couplings with the electron spin of a single nitrogen-vacancy (NV) center; such nuclear spins have outstandingly long coherence times. Among the hyperfine couplings in the NV center, the nearest neighbor 13C nuclear spins have the largest coupling strength. Nearest neighbor 13C nuclear spins have the potential to perform fastest gate operations, providing highest fidelity in quantum computing. Herein, we report on the control of coherences in the NV center where all three nearest neighbor carbons are of the 13C isotope. Coherence among the three and four qubits are generated and analyzed at room temperature.

  10. Nuclear magnetic spin-rotational relaxation times for linear molecules

    Microsoft Academic Search

    James McConnell

    1982-01-01

    The stochastic differential equation study of nuclear magnetic relaxation by spin-rotational interactions is applied to the linear rotator model of the molecule. Inertial effects are included in the calculations, which are performed analytically. Expressions are derived for the spin-rotational contributions to the longitudinal and transverse relaxation times, and for the spin-rotational correlation time.

  11. Theory of box-model hyperfine couplings and transport signatures of long-range nuclear-spin coherence in a quantum-dot spin valve

    NASA Astrophysics Data System (ADS)

    Chesi, Stefano; Coish, W. A.

    2015-06-01

    We have theoretically analyzed coherent nuclear-spin dynamics induced by electron transport through a quantum-dot spin valve. The hyperfine interaction between electron and nuclear spins in a quantum dot allows for the transfer of angular momentum from spin-polarized electrons injected from ferromagnetic or half-metal leads to the nuclear spin system under a finite voltage bias. Accounting for a local nuclear-spin dephasing process prevents the system from becoming stuck in collective dark states, allowing a large nuclear polarization to be built up in the long-time limit. After reaching a steady state, reversing the voltage bias induces a transient current response as the nuclear polarization is reversed. Long-range nuclear-spin coherence leads to a strong enhancement of spin-flip transition rates (by an amount proportional to the number of nuclear spins) and is revealed by an intense current burst, analogous to superradiant light emission. The crossover to a regime with incoherent spin flips occurs on a relatively long-time scale, on the order of the single-nuclear-spin dephasing time, which can be much longer than the time scale for the superradiant current burst. This conclusion is confirmed through a general master equation. For the two limiting regimes (coherent/incoherent spin flips), the general master equation recovers our simpler treatment based on rate equations, but is also applicable at intermediate dephasing. Throughout this work, we assume uniform hyperfine couplings, which yield the strongest coherent enhancement. We propose realistic strategies, based on isotopic modulation and wave-function engineering in core-shell nanowires, to realize this analytically solvable "box-model" of hyperfine couplings.

  12. Nanoscale magnetometry using a single spin system in diamond

    E-print Network

    R. S. Said; D. W. Berry; J. Twamley

    2011-03-24

    We propose a protocol to estimate magnetic fields using a single nitrogen-vacancy (N-V) center in diamond, where the estimate precision scales inversely with time, ~1/T$, rather than the square-root of time. The method is based on converting the task of magnetometry into phase estimation, performing quantum phase estimation on a single N-V nuclear spin using either adaptive or nonadaptive feedback control, and the recently demonstrated capability to perform single-shot readout within the N-V [P. Neumann et. al., Science 329, 542 (2010)]. We present numerical simulations to show that our method provides an estimate whose precision scales close to ~1/T (T is the total estimation time), and moreover will give an unambiguous estimate of the static magnetic field experienced by the N-V. By combining this protocol with recent proposals for scanning magnetometry using an N-V, our protocol will provide a significant decrease in signal acquisition time while providing an unambiguous spatial map of the magnetic field.

  13. Squeezing and entangling nuclear spins in helium 3

    E-print Network

    Gael Reinaudi; Alice Sinatra; Aurelien Dantan; Michel Pinard

    2006-01-09

    We present a realistic model for transferring the squeezing or the entanglement of optical field modes to the collective ground state nuclear spin of $^3$He using metastability exchange collisions. We discuss in detail the requirements for obtaining good quantum state transfer efficiency and study the possibility to readout the nuclear spin state optically.

  14. Nuclear spin polarization in silicon nanostructures with charge carrier injection

    Microsoft Academic Search

    A. L. Danilyuk; V. E. Borisenko

    2006-01-01

    We theoretically examine injection polarization of nuclear spins in silicon nanostructures with hyperfine interaction of nuclei\\u000a with excited triplet states. We predict the possibility of the appearance of self-sustaining nuclear spin polarization, initiated\\u000a by an external field. We show that if the external magnetic field is varied, we observe up to a 600-fold jump in the number\\u000a of spin-polarized nuclei.

  15. Nuclear spin polarization in silicon nanostructures with charge carrier injection

    Microsoft Academic Search

    A. L. Danilyuk; V. E. Borisenko

    2006-01-01

    We theoretically examine injection polarization of nuclear spins in silicon nanostructures with hyperfine interaction of nuclei with excited triplet states. We predict the possibility of the appearance of self-sustaining nuclear spin polarization, initiated by an external field. We show that if the external magnetic field is varied, we observe up to a 600-fold jump in the number of spin-polarized nuclei.

  16. Nuclear spin polarization transfer across an organic-semiconductor interface

    NASA Astrophysics Data System (ADS)

    Goehring, Lucas; Michal, Carl A.

    2003-11-01

    Motivated by Tycko's proposal to harness optically pumped nuclear spin polarization for the enhancement of nuclear magnetic resonance (NMR) signals from biological macromolecules, we investigate the transfer of thermal nuclear spin polarization between 1H or 19F in an organic overlayer and 31P at the surface of micron-sized InP particles by Hartmann-Hahn cross polarization. Comparison with analytic and numerical models indicates that the total quantity of polarization transferred across the semiconductor-organic interface is limited by the relatively short room-temperature 1H T1? (11 ms) and the slow diffusion of nuclear spin polarization in the semiconductor. Models and spin-counting experiments indicate that we are able to transfer approximately 20% of the total nuclear spin polarization originating in the organic overlayer to the semiconductor, supporting the feasibility of transferred optically pumped NMR.

  17. Decoherence of nuclear spins in the frozen core of an electron spin

    NASA Astrophysics Data System (ADS)

    Guichard, R.; Balian, S. J.; Wolfowicz, G.; Mortemousque, P. A.; Monteiro, T. S.

    2015-06-01

    Hybrid qubit systems combining electronic spins with nearby ("proximate") nuclear spin registers offer a promising avenue towards quantum information processing, with even multispin error-correction protocols recently demonstrated in diamond. However, for the important platform offered by spins of donor atoms in cryogenically cooled silicon, decoherence mechanisms of 29Si proximate nuclear spins are not yet well understood. The reason is partly because proximate spins lie within a so-called "frozen core" region where the donor electronic hyperfine interaction strongly suppresses nuclear dynamics. We investigate the decoherence of a central proximate nuclear qubit arising from quantum spin baths outside, as well as inside, the frozen core around the donor electron. We consider the effect of a very large nuclear spin bath comprising many (?108 ) weakly contributing pairs outside the frozen core (the "far bath"). We also propose that there may be an important contribution from a few (of order 100) symmetrically sited nuclear spin pairs ("equivalent pairs"), which were not previously considered because their effect is negligible outside the frozen core. If equivalent pairs represent a measurable source of decoherence, nuclear coherence decays could provide sensitive probes of the symmetries of electronic wave functions. For the phosphorus donor system, we obtain T2 n values of order 1 second for both the far-bath and equivalent-pair models, confirming the suitability of proximate nuclei in silicon as very-long-lived spin qubits.

  18. OSP Quantum Mechanics: Single Measurments of Spin States Worksheet

    NSDL National Science Digital Library

    Belloni, Mario

    This set of tutorial worksheets, based on the OSP Quantum Mechanics Simulations, help students explore the measurement of quantum spins. The tutorial starts with an introduction of the physics of spins, and then presents the results of a single measurement on pure, mixed, and superposition states.

  19. Simulation of extended periodic systems of nuclear spins

    NASA Astrophysics Data System (ADS)

    Hodgkinson, Paul; Sakellariou, Dimitris; Emsley, Lyndon

    2000-08-01

    Simulations of exact spin dynamics in systems of multiple nuclear spins are limited to relatively small numbers of spins by the large size of the Hamiltonian matrices for dipolar-coupled spin systems. We propose using the translational symmetry of periodic (crystalline) systems to block-diagonalize both the Hamiltonian and the density matrix and thus extend the range of exact calculation. Although this method has general application whenever the density matrix treatment is valid, the method is illustrated using simulations of spin diffusion in one-dimensional spin-1/2 lattices. Clear evidence of convergence towards the limit of an infinitely extended lattice is seen.

  20. Spin Modes in Nuclei and Nuclear Forces

    SciTech Connect

    Suzuki, Toshio [Department of Physics and Graduate School of Integrated Basic Sciences, College of Humanities and Sciences, Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan) and Center for Nuclear Study, University of Tokyo, Hirosawa, Wako-shi, Saitama, 351-0198 (Japan); Otsuka, Takaharu [Department of Physics and Center for Nuclear Study, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2011-05-06

    Spin modes in stable and unstable exotic nuclei are studied and important roles of tensor and three-body forces on nuclear structure are discussed. New shell model Hamiltonians, which have proper tensor components, are shown to explain shell evolutions toward drip-lines and spin properties of both stable and exotic nuclei, for example, Gamow-Teller transitions in {sup 12}C and {sup 14}C and an anomalous M1 transition in {sup 17}C. The importance and the necessity of the repulsive monopole corrections in isospin T = 1 channel to the microscopic two-body interactions are pointed out. The corrections are shown to lead to the proper shell evolutions in neutron-rich isotopes. The three-body force, in particular the Fujita-Miyazawa force induced by {Delta} excitations, is pointed out to be responsible for the repulsive corrections among the valence neutrons. The important roles of the three-body force on the energies and transitions in exotic oxygen and calcium isotopes are demonstrated.

  1. Protection of centre spin coherence by dynamic nuclear spin polarization in diamond

    NASA Astrophysics Data System (ADS)

    Liu, Gang-Qin; Jiang, Qian-Qing; Chang, Yan-Chun; Liu, Dong-Qi; Li, Wu-Xia; Gu, Chang-Zhi; Po, Hoi Chun; Zhang, Wen-Xian; Zhao, Nan; Pan, Xin-Yu

    2014-08-01

    We experimentally investigate the protection of electron spin coherence of a nitrogen-vacancy (NV) centre in diamond by dynamic nuclear spin polarization (DNP). The electron spin decoherence of an NV centre is caused by the magnetic field fluctuation of the 13C nuclear spin bath, which contributes large thermal fluctuation to the centre electron spin when it is in an equilibrium state at room temperature. To address this issue, we continuously transfer the angular momentum from electron spin to nuclear spins, and pump the nuclear spin bath to a polarized state under the Hartmann-Hahn condition. The bath polarization effect is verified by the observation of prolongation of the electron spin coherence time (T*2). Optimal conditions for the DNP process, including the pumping pulse duration and repeat numbers, are proposed by numerical simulation and confirmed by experiment. We also studied the depolarization effect of laser pulses. Our results provide a new route for quantum information processing and quantum simulation using the polarized nuclear spin bath.

  2. Selective coupling of individual electron and nuclear spins with integrated all-spin coherence protection

    NASA Astrophysics Data System (ADS)

    Terletska, Hanna; Dobrovitski, Viatcheslav

    2015-03-01

    The electron spin of the NV center in diamond is a promising platform for spin sensing. Applying the dynamical decoupling, the NV electron spin can be used to detect the individual weakly coupled carbon-13 nuclear spins in diamond and employ them for small-scale quantum information processing. However, the nuclear spins within this approach remain unprotected from decoherence, which ultimately limits the detection and restricts the fidelity of the quantum operation. Here we investigate possible schemes for combining the resonant decoupling on the NV spin with the decoherence protection of the nuclear spins. Considering several schemes based on pulse and continuous-wave decoupling, we study how the joint electron-nuclear spin dynamics is affected. We identify regimes where the all-spin coherence protection improves the detection and manipulation. We also discuss potential applications of the all-spin decoupling for detecting spins outside diamond, with the purpose of implementing the nanoscale NMR. This work was supported by the US Department of Energy Basic Energy Sciences (Contract No. DE-AC02-07CH11358).

  3. Nonequilibrium intrinsic spin torque in a single nanomagnet

    NASA Astrophysics Data System (ADS)

    Manchon, Aurelien

    2009-03-01

    The spin transfer torque usually observed in metallic and tunneling spin-valves, as well as magnetic domain walls, comes from the transfer of the transverse spin-current of conduction electrons to the magnetization [1]. Therefore, it requires both a non collinear configuration of the magnetic structure (or inhomogeneous magnetic texture in the case of domain walls) and magneto-resistive effects. However, a number of magnetic systems show magneto-resistive effects in a single magnetic layer, such as anisotropic magnetoresistance (AMR) [2]. In the presence of spin-orbit interaction (SOI) the electron scattering depends on the magnetization direction. Recent theoretical studies suggest that in such systems, a transverse component of the spin density builds up, due to the spin-dependent scattering introduced by the spin-orbit coupling. Consequently, a transverse spin density arises from intrinsic properties of the band structure without the need of non-collinear magnetization texture. In the case of a single ferromagnet with spin-orbit interaction, the exchange interaction between the accumulated spin and the magnetization gives rise a spin torque on the magnetization. We show that this torque can be used to control the magnetization direction injecting current densities as low as 10?5-10?6 A/cm?2, comparable or lower than the spin transfer effect. We first study the general case of a single ferromagnetic layer with spin-orbit interaction and then focus on the cases of effective Hamiltonians, such as Rashba and Dresselhaus SOI, as well as Luttinger hole systems. We discuss the relation between the spin torque and the spatial inversion symmetry of various forms of spin-orbit couplings and compare this spin torque with the conventional spin transfer torque. We finally discuss several magnetic systems for possible experimental realization. This work was done in collaboration with Shufeng Zhang. [1] ] J.C. Slonczewski, J. Magn. Magn. Mater. 159, L1 (1996); L. Berger, Phys. Rev. B 54, 9353 (1996). [2] T.R. McGuire and R.I. Potter, IEEE Trans. Mag. 11, 1018 (1975).

  4. Single Spin Asymmetries in Heavy Quark and Antiquark Productions

    E-print Network

    Feng Yuan; Jian Zhou

    2008-06-11

    The single transverse spin asymmetries in heavy quark and anti-quark production from the quark-antiquark annihilation channel contribution is studied by taking into account the initial and final state interactions effects. Because of the different color charges, the final state interaction effects lead to about a factor of 3 difference in the spin asymmetry for heavy quark over that for the anti-quark in the valence region of low energy pp collisions. The experimental study of this model-independent prediction shall provide a crucial test for the underlying mechanism for the single spin asymmetry phenomena.

  5. Room temperature hyperpolarization of nuclear spins in bulk

    PubMed Central

    Tateishi, Kenichiro; Negoro, Makoto; Nishida, Shinsuke; Kagawa, Akinori; Morita, Yasushi; Kitagawa, Masahiro

    2014-01-01

    Dynamic nuclear polarization (DNP), a means of transferring spin polarization from electrons to nuclei, can enhance the nuclear spin polarization (hence the NMR sensitivity) in bulk materials at most 660 times for 1H spins, using electron spins in thermal equilibrium as polarizing agents. By using electron spins in photo-excited triplet states instead, DNP can overcome the above limit. We demonstrate a 1H spin polarization of 34%, which gives an enhancement factor of 250,000 in 0.40 T, while maintaining a bulk sample (?0.6 mg, ?0.7 × 0.7 × 1 mm3) containing >1019 1H spins at room temperature. Room temperature hyperpolarization achieved with DNP using photo-excited triplet electrons has potentials to be applied to a wide range of fields, including NMR spectroscopy and MRI as well as fundamental physics. PMID:24821773

  6. Detection of atomic spin labels in a lipid bilayer using a single-spin nanodiamond probe.

    PubMed

    Kaufmann, Stefan; Simpson, David A; Hall, Liam T; Perunicic, Viktor; Senn, Philipp; Steinert, Steffen; McGuinness, Liam P; Johnson, Brett C; Ohshima, Takeshi; Caruso, Frank; Wrachtrup, Jörg; Scholten, Robert E; Mulvaney, Paul; Hollenberg, Lloyd

    2013-07-01

    Magnetic field fluctuations arising from fundamental spins are ubiquitous in nanoscale biology, and are a rich source of information about the processes that generate them. However, the ability to detect the few spins involved without averaging over large ensembles has remained elusive. Here, we demonstrate the detection of gadolinium spin labels in an artificial cell membrane under ambient conditions using a single-spin nanodiamond sensor. Changes in the spin relaxation time of the sensor located in the lipid bilayer were optically detected and found to be sensitive to near-individual (4 ± 2) proximal gadolinium atomic labels. The detection of such small numbers of spins in a model biological setting, with projected detection times of 1 s [corresponding to a sensitivity of ?5 Gd spins per Hz(1/2)], opens a pathway for in situ nanoscale detection of dynamical processes in biology. PMID:23776230

  7. Detection of atomic spin labels in a lipid bilayer using a single-spin nanodiamond probe

    PubMed Central

    Kaufmann, Stefan; Simpson, David A.; Hall, Liam T.; Perunicic, Viktor; Senn, Philipp; Steinert, Steffen; McGuinness, Liam P.; Johnson, Brett C.; Ohshima, Takeshi; Caruso, Frank; Wrachtrup, Jörg; Scholten, Robert E.; Mulvaney, Paul; Hollenberg, Lloyd

    2013-01-01

    Magnetic field fluctuations arising from fundamental spins are ubiquitous in nanoscale biology, and are a rich source of information about the processes that generate them. However, the ability to detect the few spins involved without averaging over large ensembles has remained elusive. Here, we demonstrate the detection of gadolinium spin labels in an artificial cell membrane under ambient conditions using a single-spin nanodiamond sensor. Changes in the spin relaxation time of the sensor located in the lipid bilayer were optically detected and found to be sensitive to near-individual (4 ± 2) proximal gadolinium atomic labels. The detection of such small numbers of spins in a model biological setting, with projected detection times of 1 s [corresponding to a sensitivity of ?5 Gd spins per Hz1/2], opens a pathway for in situ nanoscale detection of dynamical processes in biology. PMID:23776230

  8. Anisotropic nuclear-spin diffusion in double quantum wells

    NASA Astrophysics Data System (ADS)

    Hatano, T.; Kume, W.; Watanabe, S.; Akiba, K.; Nagase, K.; Hirayama, Y.

    2015-03-01

    Nuclear spin diffusion in double quantum wells (QWs) is examined by using dynamic nuclear polarization (DNP) at a Landau level filling factor ? =2 /3 spin phase transition (SPT). The longitudinal resistance increases during the DNP of one of the two QW (the "polarization QW") by means of a large applied current and starts to decrease just after the termination of the DNP. On the other hand, the longitudinal resistance of the other QW (the "detection QW") continuously increases for approximately 2 h after the termination of the DNP of the polarization QW. It is therefore concluded that the nuclear spins diffuse from the polarization QW to the detection QW. The time evolution of the longitudinal resistance of the polarization QW is explained mainly by the nuclear spin diffusion in the in-plane direction. In contrast, that of the detection QW manifests much slower nuclear diffusion in the perpendicular direction through the AlGaAs barrier.

  9. Pulsed Nuclear Magnetic Resonance: Spin Echoes MIT Department of Physics

    E-print Network

    Seager, Sara

    Pulsed Nuclear Magnetic Resonance: Spin Echoes MIT Department of Physics (Dated: February 5, 2014) In this experiment, the phenomenon of Nuclear Magnetic Resonance (NMR) is used to determine the magnetic moments-factor in atomic spectroscopy and is given by g = (µ/µN )/I, (2) and µN is the nuclear magneton, e /2mp

  10. Single Spin Asymmetries in the BRAHMS Experiment

    E-print Network

    F. Videbaek; for the BRAHMS collaboration

    2005-08-11

    The BRAHMS experiment at RHIC has the capability to measure the transverse spin asymmetries in polarized pp induced pion production at RHIC. The first results from the short run-4 show a signaificant asymmetry for pi-plus and pi-minus at moderate xF. The trend of the data is in agreement with lower energy data while the absolute value are surprisingly large.

  11. Cryogenic single-chip electron spin resonance detector

    NASA Astrophysics Data System (ADS)

    Gualco, Gabriele; Anders, Jens; Sienkiewicz, Andrzej; Alberti, Stefano; Forró, László; Boero, Giovanni

    2014-10-01

    We report on the design and characterization of a single-chip electron spin resonance detector, operating at a frequency of about 20 GHz and in a temperature range extending at least from 300 K down to 4 K. The detector consists of an LC oscillator formed by a 200 ?m diameter single turn aluminum planar coil, a metal-oxide-metal capacitor, and two metal-oxide-semiconductor field effect transistors used as negative resistance network. At 300 K, the oscillator has a frequency noise of 20 Hz/Hz1/2 at 100 kHz offset from the 20 GHz carrier. At 4 K, the frequency noise is about 1 Hz/Hz1/2 at 10 kHz offset. The spin sensitivity measured with a sample of DPPH is 108 spins/Hz1/2 at 300 K and down to 106 spins/Hz1/2 at 4 K.

  12. Efficient Readout of a Single Spin State in Diamond via Spin-to-Charge Conversion.

    PubMed

    Shields, B J; Unterreithmeier, Q P; de Leon, N P; Park, H; Lukin, M D

    2015-04-01

    Efficient readout of individual electronic spins associated with atomlike impurities in the solid state is essential for applications in quantum information processing and quantum metrology. We demonstrate a new method for efficient spin readout of nitrogen-vacancy (NV) centers in diamond. The method is based on conversion of the electronic spin state of the NV to a charge-state distribution, followed by single-shot readout of the charge state. Conversion is achieved through a spin-dependent photoionization process in diamond at room temperature. Using NVs in nanofabricated diamond beams, we demonstrate that the resulting spin readout noise is within a factor of 3 of the spin projection noise level. Applications of this technique for nanoscale magnetic sensing are discussed. PMID:25884129

  13. Engineering Nuclear spin has now been associated with Nobel Prizes

    E-print Network

    Chemical Engineering Nuclear spin has now been associated with Nobel Prizes in Physics, Chemistry-2003, Professor Reimer won the Donald Sterling Noyce Prize, the AIChE Northern California Section Award and the UC

  14. Nuclear magnetic spin-rotational relaxation times for symmetric molecules

    Microsoft Academic Search

    James McConnell

    1982-01-01

    It is shown that the problem of calculating times related to nuclear magnetic spin-rotational interactions may be solved for the symmetric rotator model of a molecule by employing the method already proposed in a general manner for asymmetric molecules that undergo rotational thermal motion. Expressions are derived for the spin-rotational correlation time and for the contributions arising from spin-rotational interactions

  15. Observation of Spin Flips with a Single Trapped Proton

    SciTech Connect

    Ulmer, S. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Institut fuer Physik, Johannes Gutenberg-Universitaet Mainz, D-55099 Mainz (Germany); Ruprecht Karls-Universitaet Heidelberg, D-69047 Heidelberg (Germany); Rodegheri, C. C. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Institut fuer Physik, Johannes Gutenberg-Universitaet Mainz, D-55099 Mainz (Germany); Blaum, K. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Ruprecht Karls-Universitaet Heidelberg, D-69047 Heidelberg (Germany); Kracke, H.; Mooser, A.; Walz, J. [Institut fuer Physik, Johannes Gutenberg-Universitaet Mainz, D-55099 Mainz (Germany); Helmholtz Institut Mainz, D-55099 Mainz (Germany); Quint, W. [Ruprecht Karls-Universitaet Heidelberg, D-69047 Heidelberg (Germany); GSI--Helmholtzzentrum fuer Schwerionenforschung, D-64291 Darmstadt (Germany)

    2011-06-24

    Radio-frequency induced spin transitions of one individual proton are observed. The spin quantum jumps are detected via the continuous Stern-Gerlach effect, which is used in an experiment with a single proton stored in a cryogenic Penning trap. This is an important milestone towards a direct high-precision measurement of the magnetic moment of the proton and a new test of the matter-antimatter symmetry in the baryon sector.

  16. Hall magnetometry of micromagnets for single-electron spin qubits

    NASA Astrophysics Data System (ADS)

    Lachance-Quirion, Dany; Camirand Lemyre, Julien; Bergeron, Laurent; Pioro-Ladrière, Michel

    2015-03-01

    The coherence time of a single-electron spin can reach tens of milliseconds when placed in the right environment. The electric-dipole interaction between such a single spin and an electric field can be engineered by the inhomogeneous magnetic field of a micromagnet. This effective spin-orbit interaction can be used to manipulate the spin through electric-dipole spin resonance, but also to couple a single spin to the electric field of a microwave cavity in the circuit QED architecture. We selected the material and improved the shape of the micromagnet in order to maximize magnetic field gradients and remanence. We perform Hall magnetometry of those improved micromagnets using Hall bars electrostatically defined in an AlGaAs/GaAs two-dimensional electron gas. The gate-voltage dependent width of the Hall bar enables us to map the averaged magnetic field of the micromagnet, which validates simulations of the inhomogeneous magnetic field profile created by the magnet. We can therefore deduce that our micromagnets can produce magnetic field differences over 200 nm of more than 200 mT.

  17. Spin-transfer torque in a single ferromagnet

    NASA Astrophysics Data System (ADS)

    Ji, Yi

    2004-03-01

    A spin polarized current, with sufficiently high current density, is able to switch a magnet or induce magnetization precession. This is the consequence of the ¡°spin-transfer torque¡+/- that originates from spin angular momentum transfer between conduction electrons and the magnetization. Previously most theories and experiments explore F/N/F trilayer and F/N multilayer structures, where F denotes a ferromagnet and N denotes a nonmagnetic metal. These structures have been generally presumed indispensable, since non-collinear magnetizations between a polarizing layer and a free layer are required to generate spin torques, and the GMR effect is essential in detecting magnetization variations. In this work, spin-transfer torque effects in a single ferromagnetic layer are demonstrated, using current injection through a point-contact at 4.2 K. Firstly, differential resistance peaks, generally regarded as signatures of spin-wave excitations, are observed in a single ferromagnetic layer in high magnetic fields [1]. The current values corresponding to the peak positions linearly depend on the external field in the range of 2 to 9 Tesla. Secondly, hysteretic current-induced switching is observed in a single ferromagnet in low magnetic fields. Both experiments can be interpreted by a simple model based on heterogeneous current distribution and domain wall scattering. Systematic variations between low field and high field regions have been investigated and the implications will be discussed. [1] Y. Ji, C. L. Chien and M. D. Stiles, Phys. Rev. Lett. 90, 106601 (2003)

  18. Single-spin observables and orbital structures in hadronic distributions

    NASA Astrophysics Data System (ADS)

    Sivers, Dennis

    2006-11-01

    Single-spin observables in scattering processes (either analyzing powers or polarizations) are highly constrained by rotational invariance and finite symmetries. For example, it is possible to demonstrate that all single-spin observables are odd under the finite transformation O=PA? where P is parity and A? is a finite symmetry that can be designated “artificial time reversal”. The operators P, O and A? all have eigenvalues ±1 so that all single-spin observables can be classified into two distinct categories: (1) P-odd and A?-even, (2) P-even and A?-odd. Within the light-quark sector of the standard model, P-odd observables are generated from pointlike electroweak processes while A?-odd observables (neglecting quark mass parameters) come from dynamic spin-orbit correlations within hadrons or within larger composite systems, such as nuclei. The effects of A?-odd dynamics can be inserted into transverse-momentum dependent constituent distribution functions and, in this paper, we construct the contribution from an orbital quark to the A?-odd quark parton distribution ?NGq/p?front(x,kTN;?2). Using this distribution, we examine the crucial role of initial- and final-state interactions in the observation of the scattering asymmetries in different hard-scattering processes. This construction provides a geometrical and dynamical interpretation of the Collins conjugation relation between single-spin asymmetries in semi-inclusive deep inelastic scattering and the asymmetries in Drell-Yan production. Finally, our construction allows us to display a significant difference between the calculation of a spin asymmetry generated by a hard-scattering mechanism involving color-singlet exchange (such as a photon) and a calculation of an asymmetry with a hard-scattering exchange involving gluons. This leads to an appreciation of the process-dependence inherent in measurements of single-spin observables.

  19. Single hadron transverse spin asymmetries from COMPASS

    SciTech Connect

    Bradamante, Franco [Trieste University, Trieste (Italy); INFN, Trieste (Italy)

    2007-06-13

    Transverse spin physics is an important part of the scientific programme of the COMPASS experiment at CERN. The analysis of the data taken with the target polarized orthogonally to the 160 GeV/c muon beam momentum has allowed to measure for the first time the Collins and Sivers asymmetries of the deuteron. Both for the positive and the negative hadrons produced in semi-inclusive DIS the measured asymmetries are small and, within errors, compatible with zero. New results for {pi}{+-} ans K{+-} are presented here.

  20. Single hadron transverse spin asymmetries from COMPASS

    E-print Network

    F. Bradamante

    2007-02-02

    Transverse spin physics is an important part of the scientific programme of the COMPASS experiment at CERN. The analysis of the data taken with the target polarized orthogonally to the 160 GeV/c muon beam momentum has allowed to measure for the first time the Collins and Sivers asymmetries of the deuteron. Both for the positive and the negative hadrons produced in semi-inclusive DIS the measured asymmetries are small and, within errors, compatible with zero. New results for charged pions and kaons are presented here.

  1. Quantifying the quantum gate fidelity of single-atom spin qubits in silicon by randomized benchmarking

    E-print Network

    J. T. Muhonen; A. Laucht; S. Simmons; J. P. Dehollain; R. Kalra; F. E. Hudson; S. Freer; K. M. Itoh; D. N. Jamieson; J. C. McCallum; A. S. Dzurak; A. Morello

    2014-10-09

    Building upon the demonstration of coherent control and single-shot readout of the electron and nuclear spins of individual 31-P atoms in silicon, we present here a systematic experimental estimate of quantum gate fidelities using randomized benchmarking of 1-qubit gates in the Clifford group. We apply this analysis to the electron and the ionized 31-P nucleus of a single P donor in isotopically purified 28-Si. We find average gate fidelities of 99.95 % for the electron, and 99.99 % for the nuclear spin. These values are above certain error correction thresholds, and demonstrate the potential of donor-based quantum computing in silicon. By studying the influence of the shape and power of the control pulses, we find evidence that the present limitation to the gate fidelity is mostly related to the external hardware, and not the intrinsic behaviour of the qubit.

  2. Excited-state spin coherence of a single nitrogen-vacancy centre in diamond

    NASA Astrophysics Data System (ADS)

    Fuchs, G. D.; Dobrovitski, V. V.; Toyli, D. M.; Heremans, F. J.; Weis, C. D.; Schenkel, T.; Awschalom, D. D.

    2010-09-01

    Nitrogen-vacancy centres in diamond are a solid-state analogue of trapped atoms, with fine structure in both the ground and excited states that may be used for advanced quantum control. These centres are promising candidates for spin-based quantum information processing and magnetometry at room temperature. Knowledge of the excited-state (ES) structure and coherence is critical to evaluating the ES as a room-temperature quantum resource, for example for a fast, optically gated swap operation with a nuclear-spin memory. Here we report experiments that probe the ES-spin coherence of single nitrogen-vacancy centres. Using a combination of pulsed-laser excitation and nanosecond-scale microwave manipulation, we observed ES Rabi oscillations, and multipulse resonant control enabled us to study coherent ES electron/nuclear-spin interactions. To understand these processes, we developed a finite-temperature theory of ES spin dynamics that also provides a pathway towards engineering longer ES spin coherence.

  3. Single-Transverse Spin Asymmetries: From DIS to Hadronic Collisions

    E-print Network

    Werner Vogelsang; Feng Yuan

    2005-09-28

    We study single-spin asymmetries in semi-inclusive deep inelastic scattering with transversely polarized target. Based on the QCD factorization approach, we consider Sivers and Collins contributions to the asymmetries. We fit simple parameterizations for the Sivers and Collins functions to the recent HERMES data, and compare to results from COMPASS. Using the fitted parameterizations for the Sivers functions, we predict the single transverse spin asymmetries for various processes in $pp$ collisions at RHIC, including the Drell-Yan process and angular correlations in dijet and jet-plus-photon production. These asymmetries are found to be sizable at forward rapidities

  4. Robust Dynamical Decoupling Sequences for Individual Nuclear Spin Addressing

    E-print Network

    J. Casanova; J. F. Haase; Z. -Y. Wang; M. B. Plenio

    2015-06-11

    We propose the use of non-equally spaced decoupling pulses for high-resolution selective addressing of nuclear spins by a quantum sensor. The analytical model of the basic operating principle is supplemented by detailed numerical studies that demonstrate the high degree of selectivity and the robustness against static and dynamic control field errors of this scheme. We exemplify our protocol with an NV center-based sensor to demonstrate that it enables the identification of individual nuclear spins that form part of a large spin ensemble.

  5. Optical Control of Nuclear Spin Ensembles in Diamond

    NASA Astrophysics Data System (ADS)

    King, Jonathan; Reimer, Jeffrey

    2012-02-01

    We present new results on the hyperpolarization of ^13C nuclear spins in diamond through optically-oriented nitrogen vacancy (NV-) defects. Optical illumination of high NV- concentration diamonds at cryogenic temperatures and 9.4 Tesla results in a negative nuclear spin temperature with measured bulk-average polarization over 5%, although local polarization may be higher. The negative spin-temperature is attributed to a population inversion within the dipolar energy levels of the NV- spin ensemble. In our quantitative model, nuclei near defects equilibrate with the NV- dipolar energy reservoir and polarization is transported to the bulk material via spin diffusion. This model is tested by investigating a series of samples with varied defect density. We also investigate the nuclear hyperpolarization of NV- containing diamond nanocrystals. Such materials may be useful for surface transfer of polarization to target molecules for enhanced NMR sensitivity. Additionally, we investigate the dynamics and decoherence of the hyperpolarized nuclear spin ensemble and its interaction with electronic defect spins. Such phenomena are of fundamental interest to the use of diamond for quantum information applications.

  6. Flux noise in SQUIDs: Electron versus nuclear spins

    NASA Astrophysics Data System (ADS)

    de Sousa, Rogerio; Laforest, Stephanie

    2015-03-01

    Superconducting Quantum Interference Devices (SQUIDs) are limited by intrinsic flux noise whose origin is unknown. We develop a method to accurately calculate the flux produced by spin impurities in realistic superconducting thin film wires, and show that the flux produced by each spin is much larger than anticipated by former calculations. Remarkably, the total flux noise power due to electron spins at the thin side surface of the wires is found to be of similar magnitude as the one due to electrons at the wide top surface of the wires. In addition, flux noise due to lattice nuclear spins in the bulk of the wires is found to be a sizable fraction of the total noise for some SQUID geometries. We discuss the relative importance of electron and nuclear spin species in determining the total noise power, and propose strategies to design SQUIDs with lower flux noise. We acknowledge support from the Canadian agency NSERC through its Discovery and Engage programs.

  7. Nuclear-spin observation of noise spectra in semiconductors

    NASA Astrophysics Data System (ADS)

    Sasaki, Susumu; Yuge, Tatsuro; Nishimori, Masashi; Kawanago, Takashi; Hirayama, Yoshiro

    2013-12-01

    We propose a systematic method of obtaining the spectra of noises that cause the decoherence of spins in solids. Based on this method, we experimentally show that this method can be applied to nuclear spins in semiconductors. We clarify that the spectral intensity must be derived from the long-time tail of the multiple-echo decay. To obtain higher-frequency noise, the inversion-pulse interval must be as short as possible, which required us to employ the alternating-phase Carr-Purcell sequence instead of the widely used Carr-Purcell Meiboom-Gill. For 75As nuclear spin in variously-doped GaAs, we observed a Lorentzian spectrum, instead of the commonly observed 1/f spectrum. This indicates that the nuclear spins are indeed in a coherently-controlled state.

  8. Nuclear-spin observation of noise spectra in semiconductors

    SciTech Connect

    Sasaki, Susumu; Nishimori, Masashi; Kawanago, Takashi [Department of Materials Science, Niigata University, Niigata 950-2181 (Japan); Yuge, Tatsuro [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan); Hirayama, Yoshiro [Department of Physics, Tohoku University, Sendai 980-8578, Japan and JST-ERATO Nuclear Spin Electronics Project, Sendai 980-8578 (Japan)

    2013-12-04

    We propose a systematic method of obtaining the spectra of noises that cause the decoherence of spins in solids. Based on this method, we experimentally show that this method can be applied to nuclear spins in semiconductors. We clarify that the spectral intensity must be derived from the long-time tail of the multiple-echo decay. To obtain higher-frequency noise, the inversion-pulse interval must be as short as possible, which required us to employ the alternating-phase Carr-Purcell sequence instead of the widely used Carr-Purcell Meiboom-Gill. For {sup 75}As nuclear spin in variously-doped GaAs, we observed a Lorentzian spectrum, instead of the commonly observed 1/f spectrum. This indicates that the nuclear spins are indeed in a coherently-controlled state.

  9. Resonator-induced dissipation of transverse nuclear-spin signals in cold nanoscale samples

    NASA Astrophysics Data System (ADS)

    Butler, Mark C.; Weitekamp, Daniel P.

    2012-03-01

    The back action of typical macroscopic resonators used for detecting nuclear magnetic resonance can cause a reversible decay of the signal, known as radiation damping. A mechanical resonator that is strongly coupled to a microscopic sample can in addition induce an irreversible dissipation of the nuclear-spin signal, distinct from radiation damping. We provide a theoretical description of resonator-induced transverse relaxation that is valid for samples of a few nuclear spins in the low-temperature regime, where quantum fluctuations play a significant role in the relaxation process, as well as for larger samples and at higher temperatures. Transverse relaxation during free evolution and during spin locking are analyzed, and simulations of relaxation in example systems are presented. In the case where an isolated spin (1)/(2) interacts with the resonator, transverse relaxation is exponential during free evolution, and the time constant for the relaxation is T2=2/Rh, where Rh is the rate constant governing the exchange of quanta between the resonator and the spin. For a system of multiple spins, the time scale of transverse relaxation during free evolution depends on the spin Hamiltonian, which can modify the relaxation process through the following effects: (1) changes in the structure of the spin-spin correlations present in the energy eigenstates, which affect the rates at which these states emit and absorb energy, (2) frequency shifts that modify emission and absorption rates within a degenerate manifold by splitting the energy degeneracy and thus suppressing the development of resonator-induced correlations within the manifold, and (3) frequency shifts that introduce a difference between the oscillation frequencies of single-quantum coherences ?ab and ?cd and average to zero the transfers between them. This averaging guarantees that the spin transitions responsible for the coupling between ?ab and ?cd cause irreversible loss of order rather than a reversible interconversion of the coherences. In systems of a few spins, transverse relaxation is accelerated by a dipolar Hamiltonian that is either the dominant term in the internal spin Hamiltonian or a weak perturbation to the chemical-shift Hamiltonian. A pure chemical-shift Hamiltonian yields exponential relaxation with T2=2/Rh in the case where the Larmor frequencies of the spins are distinct and sufficiently widely spaced. During spin locking with a nutation frequency fast enough to average the evolution under the internal spin Hamiltonian but not the interactions occurring during the correlation time of the resonator, relaxation of the spin-locked component is exponential with time constant T1?=2/Rh.

  10. Gaussian approximation and single-spin measurement in magnetic resonance force microscopy with spin noise

    SciTech Connect

    Raghunathan, Shesha; Brun, Todd A. [Center for Quantum Information Science and Technology, Communication Sciences Institute, Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089 (United States); Goan, Hsi-Sheng [Department of Physics and Center for Theoretical Sciences, National Taiwan University, Taipei 10617, Taiwan (China); Center for Quantum Science and Engineering, National Taiwan University, Taipei 10617, Taiwan (China)

    2010-11-15

    A promising technique for measuring single electron spins is magnetic resonance force microscopy (MRFM), in which a microcantilever with a permanent magnetic tip is resonantly driven by a single oscillating spin. The most effective experimental technique is the oscillating cantilever-driven adiabatic reversals (OSCAR) protocol, in which the signal takes the form of a frequency shift. If the quality factor of the cantilever is high enough, this signal will be amplified over time to the point where it can be detected by optical or other techniques. An important requirement, however, is that this measurement process occurs on a time scale that is short compared to any noise which disturbs the orientation of the measured spin. We describe a model of spin noise for the MRFM system and show how this noise is transformed to become time dependent in going to the usual rotating frame. We simplify the description of the cantilever-spin system by approximating the cantilever wave function as a Gaussian wave packet and show that the resulting approximation closely matches the full quantum behavior. We then examine the problem of detecting the signal for a cantilever with thermal noise and spin with spin noise, deriving a condition for this to be a useful measurement.

  11. Gigahertz dynamics of a strongly driven single quantum spin.

    PubMed

    Fuchs, G D; Dobrovitski, V V; Toyli, D M; Heremans, F J; Awschalom, D D

    2009-12-11

    Two-level systems are at the core of numerous real-world technologies such as magnetic resonance imaging and atomic clocks. Coherent control of the state is achieved with an oscillating field that drives dynamics at a rate determined by its amplitude. As the strength of the field is increased, a different regime emerges where linear scaling of the manipulation rate breaks down and complex dynamics are expected. By calibrating the spin rotation with an adiabatic passage, we have measured the room-temperature "strong-driving" dynamics of a single nitrogen vacancy center in diamond. With an adiabatic passage to calibrate the spin rotation, we observed dynamics on sub-nanosecond time scales. Contrary to conventional thinking, this breakdown of the rotating wave approximation provides opportunities for time-optimal quantum control of a single spin. PMID:19965386

  12. Matrix Formalism for Spin Dynamics Near a Single Depolarization Resonance

    SciTech Connect

    Chao, Alexander W.; /SLAC

    2005-10-26

    A matrix formalism is developed to describe the spin dynamics in a synchrotron near a single depolarization resonance as the particle energy (and therefore its spin precession frequency) is varied in a prescribed pattern as a function of time such as during acceleration. This formalism is first applied to the case of crossing the resonance with a constant crossing speed and a finite total step size, and then applied also to other more involved cases when the single resonance is crossed repeatedly in a prescribed manner consisting of linear ramping segments or sudden jumps. How repeated crossings produce an interference behavior is discussed using the results obtained. For a polarized beam with finite energy spread, a spin echo experiment is suggested to explore this interference effect.

  13. Nuclear-spin-dependent parity violation in diatomic molecular ions

    NASA Astrophysics Data System (ADS)

    Borschevsky, A.; Iliaš, M.; Dzuba, V. A.; Beloy, K.; Flambaum, V. V.; Schwerdtfeger, P.

    2012-11-01

    Nuclear-spin-dependent (NSD) parity-violating (PV) effects can be strongly enhanced in diatomic molecules containing heavy atoms. Future measurements are anticipated to provide nuclear anapole moments and strength constants for PV nuclear forces. In light molecules, the NSD electroweak electron-nucleus interaction may also be detected. Here we calculate NSD PV effects for molecular ions. Our calculations are motivated by rapid developments in trapping techniques for such systems at low temperatures.

  14. High-efficiency resonant amplification of weak magnetic fields for single spin magnetometry at room temperature

    NASA Astrophysics Data System (ADS)

    Trifunovic, Luka; Pedrocchi, Fabio L.; Hoffman, Silas; Maletinsky, Patrick; Yacoby, Amir; Loss, Daniel

    2015-06-01

    Magnetic resonance techniques not only provide powerful imaging tools that have revolutionized medicine, but they have a wide spectrum of applications in other fields of science such as biology, chemistry, neuroscience and physics. However, current state-of-the-art magnetometers are unable to detect a single nuclear spin unless the tip-to-sample separation is made sufficiently small. Here, we demonstrate theoretically that by placing a ferromagnetic particle between a nitrogen–vacancy magnetometer and a target spin, the magnetometer sensitivity is improved dramatically. Using materials and techniques that are already experimentally available, our proposed set-up is sensitive enough to detect a single nuclear spin within ten milliseconds of data acquisition at room temperature. The sensitivity is practically unchanged when the ferromagnet surface to the target spin separation is smaller than the ferromagnet lateral dimensions; typically about a tenth of a micrometre. This scheme further benefits when used for nitrogen–vacancy ensemble measurements, enhancing sensitivity by an additional three orders of magnitude.

  15. High-efficiency resonant amplification of weak magnetic fields for single spin magnetometry at room temperature.

    PubMed

    Trifunovic, Luka; Pedrocchi, Fabio L; Hoffman, Silas; Maletinsky, Patrick; Yacoby, Amir; Loss, Daniel

    2015-06-01

    Magnetic resonance techniques not only provide powerful imaging tools that have revolutionized medicine, but they have a wide spectrum of applications in other fields of science such as biology, chemistry, neuroscience and physics. However, current state-of-the-art magnetometers are unable to detect a single nuclear spin unless the tip-to-sample separation is made sufficiently small. Here, we demonstrate theoretically that by placing a ferromagnetic particle between a nitrogen-vacancy magnetometer and a target spin, the magnetometer sensitivity is improved dramatically. Using materials and techniques that are already experimentally available, our proposed set-up is sensitive enough to detect a single nuclear spin within ten milliseconds of data acquisition at room temperature. The sensitivity is practically unchanged when the ferromagnet surface to the target spin separation is smaller than the ferromagnet lateral dimensions; typically about a tenth of a micrometre. This scheme further benefits when used for nitrogen-vacancy ensemble measurements, enhancing sensitivity by an additional three orders of magnitude. PMID:25961508

  16. Control of single-spin magnetic anisotropy by exchange coupling.

    PubMed

    Oberg, Jenny C; Calvo, M Reyes; Delgado, Fernando; Moro-Lagares, María; Serrate, David; Jacob, David; Fernández-Rossier, Joaquín; Hirjibehedin, Cyrus F

    2014-01-01

    The properties of quantum systems interacting with their environment, commonly called open quantum systems, can be affected strongly by this interaction. Although this can lead to unwanted consequences, such as causing decoherence in qubits used for quantum computation, it can also be exploited as a probe of the environment. For example, magnetic resonance imaging is based on the dependence of the spin relaxation times of protons in water molecules in a host's tissue. Here we show that the excitation energy of a single spin, which is determined by magnetocrystalline anisotropy and controls its stability and suitability for use in magnetic data-storage devices, can be modified by varying the exchange coupling of the spin to a nearby conductive electrode. Using scanning tunnelling microscopy and spectroscopy, we observe variations up to a factor of two of the spin excitation energies of individual atoms as the strength of the spin's coupling to the surrounding electronic bath changes. These observations, combined with calculations, show that exchange coupling can strongly modify the magnetic anisotropy. This system is thus one of the few open quantum systems in which the energy levels, and not just the excited-state lifetimes, can be renormalized controllably. Furthermore, we demonstrate that the magnetocrystalline anisotropy, a property normally determined by the local structure around a spin, can be tuned electronically. These effects may play a significant role in the development of spintronic devices in which an individual magnetic atom or molecule is coupled to conducting leads. PMID:24317285

  17. High precision quantum control of single donor spins in silicon

    E-print Network

    Rajib Rahman; Cameron J. Wellard; Forrest R. Bradbury; Marta Prada; Jared H. Cole; Gerhard Klimeck; Lloyd C. L. Hollenberg

    2007-05-15

    The Stark shift of the hyperfine coupling constant is investigated for a P donor in Si far below the ionization regime in the presence of interfaces using Tight-binding and Band Minima Basis approaches and compared to the recent precision measurements. The TB electronic structure calculations included over 3 million atoms. In contrast to previous effective mass based results, the quadratic Stark coefficient obtained from both theories agrees closely with the experiments. This work represents the most sensitive and precise comparison between theory and experiment for single donor spin control. It is also shown that there is a significant linear Stark effect for an impurity near the interface, whereas, far from the interface, the quadratic Stark effect dominates. Such precise control of single donor spin states is required particularly in quantum computing applications of single donor electronics, which forms the driving motivation of this work.

  18. Long-range two-qubit gate between nuclear spins in diamond mediated via an optical cavity

    NASA Astrophysics Data System (ADS)

    Auer, Adrian; Burkard, Guido

    2015-03-01

    Nitrogen-vacancy (NV) centers in diamond represent a promising possibility for a solid-state based realization of a qubit due to their excellent electron- and nuclear-spin coherence properties. Single-qubit gates for the nitrogen nuclear spin have been implemented. Here, we extend an earlier proposal for cavity-mediated coupling between NV electron spins and develop a scheme to implement a universal two-qubit gate between 14N or 15N nuclear spins. By virtually exciting a single NV center with an external laser field, a photon can be scattered into a surrounding cavity; we show that this process depends on the spin state of the nitrogen nucleus. For the two-qubit gate, we consider two NV centers coupled to a common cavity mode and each being excited individually. Virtual cavity excitation can then mediate an effective interaction between the NV nuclear spin qubits, generating a controlled-Z gate. Operation times for the gate implementation are found to be below 100 nanoseconds, which is orders of magnitude faster than the decoherence time of nuclear spin qubits in diamond.

  19. Spin constraints on nuclear energy density functionals

    NASA Astrophysics Data System (ADS)

    Robledo, L. M.; Bernard, R. N.; Bertsch, G. F.

    2014-02-01

    The Gallagher-Moszkowski rule in the spectroscopy of odd-odd nuclei imposes a new spin constraint on the energy functionals for self-consistent mean field theory. The commonly used parametrization of the effective three-body interaction in the Gogny and Skyrme families of energy functionals is ill suited to satisfy the spin constraint. In particular, the Gogny parametrization of the three-body interaction has the spin dependence opposite to that required by the observed spectra. The two-body part has a correct sign, but in combination the rule is violated as often as not. We conclude that a new functional form is needed for the effective three-body interaction that can take into better account the different spin-isospin channels of the interaction.

  20. Nuclear Spin Relaxation in Acetylene Gas

    Microsoft Academic Search

    Myong-Ku Ahn; Charles S. Johnson Jr.

    1969-01-01

    Proton spin–lattice relaxation times (T1) have been measured in acetylene gas between ?50 °C and 19°C using a CAT for signal averaging. T1 was found to depend linearly on the number density &rgr; in the range of these measurements (0.1 to 0.9 amagat). The temperature dependence of the ratio T1?&rgr; indicates that the spin–rotational interaction provides the dominant relaxation mechanism.

  1. Nuclear spin-lattice relaxation of dilute spins in semiconducting diamond

    NASA Astrophysics Data System (ADS)

    Hoch, M. J. R.; Reynhardt, E. C.

    1988-06-01

    Absorption line shape and spin-lattice relaxation-time measurements have been made on 13C nuclei (1.1% abundant) in a type-IIb single-crystal semiconducting diamond. The line shape measurements are consistent with theoretical predictions for a dilute spin system. Over the temperature range 295-375 K, the spin-lattice relaxation time is long (3-4 h) and shows a temperature dependence which may be explained by means of a model in which spin diffusion plays a role, and the paramagnetic acceptor centers relax via an Orbach-type process involving excited states near the valence band.

  2. Combustion resistance of the 129Xe hyperpolarized nuclear spin state.

    PubMed

    Stupic, Karl F; Six, Joseph S; Olsen, Michael D; Pavlovskaya, Galina E; Meersmann, Thomas

    2013-01-01

    Using a methane-xenon mixture for spin exchange optical pumping, MRI of combustion was enabled. The (129)Xe hyperpolarized nuclear spin state was found to sufficiently survive the complete passage through the harsh environment of the reaction zone. A velocity profile (V(z)(z)) of a flame was recorded to demonstrate the feasibility of MRI velocimetry of transport processes in combustors. PMID:23165418

  3. The nuclear spin response to intermediate energy protons

    Microsoft Academic Search

    F. T. Baker; L. Bimbot; B. Castel; R. W. Fergerson; C. Glashausser; A. Green; O. Hausser; K. Hicks; K. Jones; C. A. Miller; S. K. Nanda; R. D. Smith; M. Vetterli; J. Wambach; R. Abegg; D. Beatty; V. Cupps; C. Djalali; R. Henderson; K. P. Jackson; R. Jeppeson; J. Lisantti; M. Morlet; R. Sawafta; W. Unkelbach; A. Willis; S. Yen

    1990-01-01

    Measurements of the spin-flip probability Snn for inclusive inelastic proton scattering around 300 MeV from nuclei between 12C and 90Zr show that an enhanced spin response near 40 MeV excitation at q ~ 100 MeV\\/c is a general feature of nuclear structure. Data for 40Ca at 800 MeV confirm that the enhancement is not a peculiarity of 300 MeV scattering.

  4. Accelerated 2D magnetic resonance spectroscopy of single spins using matrix completion

    E-print Network

    Jochen Scheuer; Alexander Stark; Matthias Kost; Martin B. Plenio; Boris Naydenov; Fedor Jelezko

    2015-07-14

    Two dimensional nuclear magnetic resonance (NMR) spectroscopy is one of the major tools for analysing the chemical structure of organic molecules and proteins. Despite its power, this technique requires long measurement times, which, particularly in the recently emerging diamond based single molecule NMR, limits its application to stable samples. Here we demonstrate a method which allows to obtain the spectrum by collecting only a small fraction of the experimental data. Our method is based on matrix completion which can recover the full spectral information from randomly sampled data points. We confirm experimentally the applicability of this technique by performing two dimensional electron spin echo envelope modulation (ESEEM) experiments on a two spin system consisting of a single nitrogen vacancy (NV) centre in diamond coupled to a single 13C nuclear spin. We show that the main peaks in the spectrum can be obtained with only 10 % of the total number of the data points. We believe that our results reported here can find an application in all types of two dimensional spectroscopy, as long as the measured matrices have a low rank.

  5. Quantum and classical correlations in electron-nuclear spin echo

    SciTech Connect

    Zobov, V. E., E-mail: rsa@iph.krasn.ru [Russian Academy of Sciences, Kirensky Institute of Physics, Siberian Branch (Russian Federation)

    2014-11-15

    The quantum properties of dynamic correlations in a system of an electron spin surrounded by nuclear spins under the conditions of free induction decay and electron spin echo have been studied. Analytical results for the time evolution of mutual information, classical part of correlations, and quantum part characterized by quantum discord have been obtained within the central-spin model in the high-temperature approximation. The same formulas describe discord in both free induction decay and spin echo although the time and magnetic field dependences are different because of difference in the parameters entering into the formulas. Changes in discord in the presence of the nuclear polarization ?{sub I} in addition to the electron polarization ?{sub S} have been calculated. It has been shown that the method of reduction of the density matrix to a two-spin electron-nuclear system provides a qualitatively correct description of pair correlations playing the main role at ?{sub S} ? ?{sub I} and small times. At large times, such correlations decay and multispin correlations ensuring nonzero mutual information and zero quantum discord become dominant.

  6. Single-chip detector for electron spin resonance spectroscopy.

    PubMed

    Yalcin, T; Boero, G

    2008-09-01

    We have realized an innovative integrated detector for electron spin resonance spectroscopy. The microsystem, consisting of an LC oscillator, a mixer, and a frequency division module, is integrated onto a single silicon chip using a conventional complementary metal-oxide-semiconductor technology. The implemented detection method is based on the measurement of the variation of the frequency of the integrated LC oscillator as a function of the applied static magnetic field, caused by the presence of a resonating sample placed over the inductor of the LC-tank circuit. The achieved room temperature spin sensitivity is about 10(10) spinsGHz(12) with a sensitive volume of about (100 microm)(3). PMID:19044436

  7. Spin instabilities of infinite nuclear matter and effective tensor interactions

    E-print Network

    J. Navarro; A. Polls

    2013-04-09

    We study the effects of the tensor force, present in modern effective nucleon-nucleon interactions, in the spin instability of nuclear and neutron matter. Stability conditions of the system against certain very low energy excitation modes are expressed in terms of Landau parameters. It is shown that in the spin case, the stability conditions are equivalent to the condition derived from the spin susceptibility, which is obtained as the zero-frequency and long-wavelength limit of the spin response function calculated in the Random Phase Approximation. Zero-range forces of the Skyrme type and finite-range forces of M3Y and Gogny type are analyzed. It is shown that for the Skyrme forces considered, the tensor effects are sizeable, and tend to increase the spin instability which appears at smaller densities than in the case that the tensor is not taken into account. On the contrary, the tensor contribution of finite range forces to the spin susceptibility is small or negligible for both isospin channels of symmetric nuclear matter as well as for neutron matter. A comparison with the spin susceptibility provided by realistic interactions is also presented.

  8. Optical Polarization of Nuclear Spins in Silicon Carbide.

    PubMed

    Falk, Abram L; Klimov, Paul V; Ivády, Viktor; Szász, Krisztián; Christle, David J; Koehl, William F; Gali, Ádám; Awschalom, David D

    2015-06-19

    We demonstrate optically pumped dynamic nuclear polarization of ^{29}Si nuclear spins that are strongly coupled to paramagnetic color centers in 4H- and 6H-SiC. The 99%±1% degree of polarization that we observe at room temperature corresponds to an effective nuclear temperature of 5???K. By combining ab initio theory with the experimental identification of the color centers' optically excited states, we quantitatively model how the polarization derives from hyperfine-mediated level anticrossings. These results lay a foundation for SiC-based quantum memories, nuclear gyroscopes, and hyperpolarized probes for magnetic resonance imaging. PMID:26197014

  9. Optical Polarization of Nuclear Spins in Silicon Carbide

    NASA Astrophysics Data System (ADS)

    Falk, Abram L.; Klimov, Paul V.; Ivády, Viktor; Szász, Krisztián; Christle, David J.; Koehl, William F.; Gali, Ádám; Awschalom, David D.

    2015-06-01

    We demonstrate optically pumped dynamic nuclear polarization of 29Si nuclear spins that are strongly coupled to paramagnetic color centers in 4 H - and 6 H -SiC. The 9 9 % ±1 % degree of polarization that we observe at room temperature corresponds to an effective nuclear temperature of 5 ? K . By combining ab initio theory with the experimental identification of the color centers' optically excited states, we quantitatively model how the polarization derives from hyperfine-mediated level anticrossings. These results lay a foundation for SiC-based quantum memories, nuclear gyroscopes, and hyperpolarized probes for magnetic resonance imaging.

  10. Nuclear spin optical rotation and Faraday effect in gaseous and liquid water

    NASA Astrophysics Data System (ADS)

    Pennanen, Teemu S.; Ikäläinen, Suvi; Lantto, Perttu; Vaara, Juha

    2012-05-01

    Nuclear spin optical rotation (NSOR) of linearly polarized light, due to the nuclear spins through the Faraday effect, provides a novel probe of molecular structure and could pave the way to optical detection of nuclear magnetization. We determine computationally the effects of the liquid medium on NSOR and the Verdet constant of Faraday rotation (arising from an external magnetic field) in water, using the recently developed theory applied on a first-principles molecular dynamics trajectory. The gas-to-liquid shifts of the relevant antisymmetric polarizability and, hence, NSOR magnitude are found to be -14% and -29% for 1H and 17O nuclei, respectively. On the other hand, medium effects both enhance the local electric field in water and, via bulk magnetization, the local magnetic field. Together these two effects partially cancel the solvation influence on the single-molecular property. We find a good agreement for the hydrogen NSOR with a recent pioneering experiment on H2O(l).

  11. Long-range spin-triplet correlations and edge spin currents in diffusive spin-orbit coupled SNS hybrids with a single spin-active interface.

    PubMed

    Alidoust, Mohammad; Halterman, Klaus

    2015-06-17

    Utilizing a SU(2) gauge symmetry technique in the quasiclassical diffusive regime, we theoretically study finite-sized two-dimensional intrinsic spin-orbit coupled superconductor/normal-metal/superconductor (S/N/S) hybrid structures with a single spin-active interface. We consider intrinsic spin-orbit interactions (ISOIs) that are confined within the N wire and absent in the s-wave superconducting electrodes (S). Using experimentally feasible parameters, we demonstrate that the coupling of the ISOIs and spin moment of the spin-active interface results in maximum singlet-triplet conversion and accumulation of spin current density at the corners of the N wire nearest the spin-active interface. By solely modulating the superconducting phase difference, we show how the opposing parities of the charge and spin currents provide an effective venue to experimentally examine pure edge spin currents not accompanied by charge currents. These effects occur in the absence of externally imposed fields and moreover are insensitive to the arbitrary orientations of the interface spin moment. The experimental implementation of these robust edge phenomena are also discussed. PMID:25996592

  12. Long-range spin-triplet correlations and edge spin currents in diffusive spin–orbit coupled SNS hybrids with a single spin-active interface

    NASA Astrophysics Data System (ADS)

    Alidoust, Mohammad; Halterman, Klaus

    2015-06-01

    Utilizing a SU(2) gauge symmetry technique in the quasiclassical diffusive regime, we theoretically study finite-sized two-dimensional intrinsic spin–orbit coupled superconductor/normal-metal/superconductor (S/N/S) hybrid structures with a single spin-active interface. We consider intrinsic spin–orbit interactions (ISOIs) that are confined within the N wire and absent in the s-wave superconducting electrodes (S). Using experimentally feasible parameters, we demonstrate that the coupling of the ISOIs and spin moment of the spin-active interface results in maximum singlet-triplet conversion and accumulation of spin current density at the corners of the N wire nearest the spin-active interface. By solely modulating the superconducting phase difference, we show how the opposing parities of the charge and spin currents provide an effective venue to experimentally examine pure edge spin currents not accompanied by charge currents. These effects occur in the absence of externally imposed fields and moreover are insensitive to the arbitrary orientations of the interface spin moment. The experimental implementation of these robust edge phenomena are also discussed.

  13. Coherent control of hyperfine-coupled electron and nuclear spins for quantum information processing

    E-print Network

    Yang, Jamie Chiaming

    2008-01-01

    Coupled electron-nuclear spins are promising physical systems for quantum information processing: By combining the long coherence times of the nuclear spins with the ability to initialize, control, and measure the electron ...

  14. Spin-orbit coupling rule in nuclear and atomic systems

    E-print Network

    J. -P. Ebran; E. Khan; A. Mutschler; D. Vretenar

    2015-06-02

    Spin-orbit coupling characterizes quantum systems such as atoms, nuclei, hypernuclei, quarkonia, etc., and is essential for understanding their spectroscopic properties. Depending on the system, the effect of spin-orbit coupling on shell structure is large in nuclei, small in quarkonia, perturbative in atoms. In the standard non-relativistic reduction of the single-particle Dirac equation, we derive a universal rule for the relative magnitude of the spin-orbit effect that applies to very different quantum systems, regardless of whether the spin-orbit coupling originates from the strong or electromagnetic interaction. It is shown that in nuclei the near equality of the mass of the nucleon and the difference between the large repulsive and attractive potentials explains the fact that spin-orbit splittings are comparable to the energy spacing between major shells. For a specific ratio between the particle mass and the effective potential whose gradient determines the spin-orbit force, we predict the occurrence of giant spin-orbit energy splittings that dominate the single-particle excitation spectrum.

  15. Engineering nuclear spin dynamics with optically pumped nitrogen-vacancy center

    E-print Network

    Ping Wang; Jiangfeng Du; Wen Yang

    2015-03-01

    We present a general theory for using an optically pumped diamond nitrogen-vacancy center as a tunable, non-equilibrium bath to control a variety of nuclear spin dynamics (such as dephasing, relaxation, squeezing, polarization, etc.) and the nuclear spin noise. It opens a new avenue towards engineering the dissipative and collective nuclear spin evolution and solves an open problem brought up by the $^{13}$C nuclear spin noise suppression experiment [E. Togan \\textit{et al}., Nature 478, 497 (2011)].

  16. Manipulating decoherence of a single solid-state spin by quantum control of its spin bath environment

    NASA Astrophysics Data System (ADS)

    de Lange, Gijs; van der Sar, Toeno; Blok, Machiel; Wang, Zhihui; Dobrovitski, Viatcheslav; Hanson, Ronald

    2011-03-01

    The coherence of solid-state spins is limited by uncontrolled interactions with their spin environment. High-fidelity single-spin control can be used to prolong the coherence by dynamically decoupling the spin from the environment [see De Lange et al., Science 330, 60 (2010)]. Here, we demonstrate a new approach towards decoherence control based on coherent manipulation of the spin bath environment itself. Our system consists of a single NV center spin in diamond, surrounded by a bath of electronic spins belonging to nitrogen impurities. By driving the bath spins resonantly and using the NV spin as a sensor, we are able to detect all transitions of the bath spins and demonstrate independent quantum control of each of them. This newly gained control opens the door to a number of exciting experiments such as measurement of the spin bath dynamics, manipulation of the spin bath correlation time, decoherence editing, and protection of NV spin coherence by suppressing the dynamics in its spin environment. In this talk we will present our latest results towards these goals.

  17. A silicon-based nuclear spin quantum computer

    Microsoft Academic Search

    B. E. Kane

    1998-01-01

    Quantum computers promise to exceed the computational efficiency of ordinary classical machines because quantum algorithms allow the execution of certain tasks in fewer steps. But practical implementation of these machines poses a formidable challenge. Here I present a scheme for implementing a quantum-mechanical computer. Information is encoded onto the nuclear spins of donor atoms in doped silicon electronic devices. Logical

  18. Creating nuclear spin entanglement using an optical degree of freedom

    SciTech Connect

    Schaffry, Marcus [Department of Materials, Oxford University, Oxford OX1 3PH (United Kingdom); Lovett, Brendon W. [Department of Materials, Oxford University, Oxford OX1 3PH (United Kingdom); SUPA, Department of Physics, Heriot Watt University, Edinburgh EH14 4AS (United Kingdom); Gauger, Erik M. [Department of Materials, Oxford University, Oxford OX1 3PH (United Kingdom); Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 (Singapore)

    2011-09-15

    Molecular nanostructures are promising building blocks for future quantum technologies, provided methods of harnessing their multiple degrees of freedom can be identified and implemented. Due to low decoherence rates, nuclear spins are considered ideal candidates for storing quantum information, while optical excitations can give rise to fast and controllable interactions for information processing. A recent paper [M. Schaffry et al., Phys. Rev. Lett. 104, 200501 (2010)] proposed a method for entangling two nuclear spins through their mutual coupling to a transient optically excited electron spin. Building on the same idea, we present here an extended and much more detailed theoretical framework, showing that this method is in fact applicable to a much wider class of molecular structures than previously discussed in the original proposal.

  19. Nanomechanical single-qubit gates and iSWAP gate of single-electron spins in a carbon nanotube

    NASA Astrophysics Data System (ADS)

    Wang, Heng; Burkard, Guido

    2015-03-01

    A universal gate set for quantum computation can be built with one-qubit and iSWAP gates. We theoretically investigate mechanically-induced single-electron spin resonance in a quantum dot and a phonon mediated iSWAP gate of two separate single electron spins in two quantum dots on a suspended carbon nanotube which is driven by an external electric field. The intrinsic spin-phonon coupling between the spin and the mechanical mode is induced by the spin-orbit coupling. Arbitrary-angle rotations about arbitrary axes of the single electron spin can be achieved by varying the frequency and the strength of the external electric driving field. If two single-electron spins in two quantum dots couple to the same vibrational mode simultaneously, the two spins are indirectly coupled via phonon exchange. Both electron spin resonance and the iSWAP gate can be turned off by suppressing the spin-phonon coupling by electrostatically shifting the electron wave function on the nanotube. Combining iSWAP and single spin gates, maximally entangled states of two spins can be generated in a single step.

  20. Tunable Spin Loading and T1 of a Silicon Spin Qubit Measured by Single-Shot Readout

    NASA Astrophysics Data System (ADS)

    Simmons, C. B.; Prance, J. R.; van Bael, B. J.; Koh, Teck Seng; Shi, Zhan; Savage, D. E.; Lagally, M. G.; Joynt, R.; Friesen, Mark; Coppersmith, S. N.; Eriksson, M. A.

    2011-04-01

    We demonstrate single-shot readout of a silicon quantum dot spin qubit, and we measure the spin relaxation time T1. We show that the rate of spin loading can be tuned by an order of magnitude by changing the amplitude of a pulsed-gate voltage, and the fraction of spin-up electrons loaded can also be controlled. This tunability arises because electron spins can be loaded through an orbital excited state. Using a theory that includes excited states of the dot and energy-dependent tunneling, we find that a global fit to the loading rate and spin-up fraction is in good agreement with the data.

  1. Nuclear Spin Gyroscope Based on an Atomic Comagnetometer

    SciTech Connect

    Kornack, T.W.; Ghosh, R.K.; Romalis, M.V. [Department of Physics, Princeton University, Princeton, New Jersey 08550 (United States)

    2005-12-02

    We describe a nuclear spin gyroscope based on an alkali-metal-noble-gas comagnetometer. Optically pumped alkali-metal vapor is used to polarize the noble-gas atoms and detect their gyroscopic precession. Spin precession due to magnetic fields as well as their gradients and transients can be cancelled in this arrangement. The sensitivity is enhanced by using a high-density alkali-metal vapor in a spin-exchange relaxation free regime. With a K-{sup 3}He comagnetometer we demonstrate rotation sensitivity of 5x10{sup -7} rad s{sup -1} Hz{sup -1/2}, equivalent to a magnetic field sensitivity of 2.5 fT/Hz{sup 1/2}. The rotation signal can be increased by a factor of 10 using {sup 21}Ne with a smaller magnetic moment. The comagnetometer is also a promising tool in searches for anomalous spin couplings beyond the standard model.

  2. Cooling of Nuclear Spins in Diamond via Dark State Spectroscopy

    NASA Astrophysics Data System (ADS)

    Singh, Swati; Pick, Adi; Lukin, Mikhail; Yelin, Susanne

    2013-05-01

    Interaction between an electronic state and its surrounding nuclear spin environment is a major source of decoherence in most artificial atomic systems. Recently, optical pumping techniques, including coherent population trapping were used to monitor and control the nuclear bath surrounding such solid state systems. We develop a semi-classical model reminiscent of VSCPT in atomic physics to explain the anomalous diffusion in the nuclear bath. We test our model by using it to explain the dark time distribution in experiments with NV centers in diamond.

  3. Spin Anisotropy Effects in Dimer Single Molecule Magnets

    NASA Astrophysics Data System (ADS)

    Efremov, Dmitri; Klemm, Richard

    2006-03-01

    We present a model of equal spin s1 dimer single molecule magnets. The spins within each dimer interact via the Heisenberg and the most general set of four quadratic anisotropic spin interactions with respective strengths J and Jj, and with the magnetic induction B. For antiferromagnetic Heisenberg couplings (J<0) and weak anisotropy interactions (|Jj/J|1), the low temperature T magnetization M(B) exhibits 2s1 steps, the height and midpoint slope of the sth step differing from their isotropic limits by corrections of O(Jj/J)^2, but the position occurring at the energy level-crossing magnetic induction Bs,s1^lc(,), where , define the direction of B. We solve the model exactly for s1=1/2, 1, and 5/2. For weakly anisotropic dimers, the Hartree approximation yields analytic formulas for M(B) and CV(B) at arbitrary s1 that accurately fit the exact solutions at sufficiently low T or large B. Low-T formulas for the inelastic neutron scattering S(q,?) and the EPR ?(?) in an extended Hartree approximation are given. Our results are discussed with regard to existing experiments on s1=5/2 Fe2 dimers, suggesting further experiments on single crystals of these and some s1=9/2 [Mn4]2 dimers are warranted.

  4. Single-spin measurement using single-electron transistors to probe two-electron systems

    Microsoft Academic Search

    B. E. Kane; N. S. McAlpine; A. S. Dzurak; R. G. Clark; G. J. Milburn; He Bi Sun; Howard Wiseman

    2000-01-01

    We present a method for measuring single spins embedded in a solid by probing\\u000atwo electron systems with a single electron transistor (SET). Restrictions\\u000aimposed by the Pauli Principle on allowed two electron states mean that the\\u000aspin state of such systems has a profound impact on the orbital states\\u000a(positions) of the electrons, a parameter which SET's are extremely

  5. Nuclear tetrahedral configurations at spin zero

    E-print Network

    Krzysztof Zberecki; Paul-Henri Heenen; Piotr Magierski

    2009-02-04

    The possibility of the existence of stable tetrahedral deformations at spin zero is investigated using the Skyrme-HFBCS approach and the generator coordinate method (GCM). The study is limited to nuclei in which the tetrahedral mode has been predicted to be favored on the basis of non self-consistent models. Our results indicate that a clear identification of tetrahedral deformations is unlikely as they are strongly mixed with the axial octupole mode. However, the excitation energies related to the tetrahedral mode are systematically lower than those of the axial octupole mode in all the nuclei included in this study.

  6. COMPASS Results on Transverse Single-Spin Asymmetries

    E-print Network

    Anna Martin

    2007-02-01

    New results on single spin asymmetries of charged hadrons produced in deep-inelastic scattering of muons on a transversely polarised LiD target are presented. The data were taken in the years 2002, 2003 and 2004 with the COMPASS spectrometer using the muon beam of the CERN SPS at 160 GeV/c. Preliminary results are given for the Sivers asymmetry and for all the three ``quark polarimeters'' presently used in COMPASS to measure the transversity distributions. The Collins and the Sivers asymmetries for charged hadrons turn out to be compatible with zero, within the small (~1%) statistical errors, at variance with the results from HERMES on a transversely polarised proton target. Similar results have been obtained for the two hadron asymmetries and for the Lambda polarisation. First attempts to describe the Collins and the Sivers asymmetries measured by COMPASS and HERMES allow to give a consistent picture of these transverse spin effects.

  7. Giant Spin Hall Effect in Single Photon Plasmonics

    E-print Network

    G. S. Agarwal; S. -A. Biehs

    2012-12-24

    We show the existence of a very large spin Hall effect of light (SHEL) in single photon plasmonics based on spontaneous emission and the dipole-dipole interaction initiated energy transfer (FRET) on plasmonic platforms. The spin orbit coupling inherent in Maxwell equations is seen in the conversion of sigma + photon to sigma - photon. The FRET is mediated by the resonant surface plasmons and hence we find very large SHEL. We present explicit results for SHEL on both graphene and metal films. We also study how the splitting of the surface plasmon on a metal film affects the SHEL. In contrast to most other works which deal with SHEL as correction to the paraxial results, we consider SHEL in the near field of dipoles which are far from paraxial.

  8. Single Spin Asymmetries of Identified Hadrons s = 62.4 and 200 GeV

    E-print Network

    Single Spin Asymmetries of Identified Hadrons in p +p at s = 62.4 and 200 GeV J.H. Lee and F, USA Measurements of xF -dependent single spin asymmetries of identified charged hadrons, ± , K± , p of transverse spin asymme- tries and Quantum Chromodynamical description of hadronic structure. 1 Introduction

  9. Spin instabilities of infinite nuclear matter and effective tensor interactions

    E-print Network

    Navarro, J

    2013-01-01

    We study the effects of the tensor force, present in modern effective nucleon-nucleon interactions, in the spin instability of nuclear and neutron matter. Stability conditions of the system against certain very low energy excitation modes are expressed in terms of Landau parameters. It is shown that in the spin case, the stability conditions are equivalent to the condition derived from the spin susceptibility, which is obtained as the zero-frequency and long-wavelength limit of the spin response function calculated in the Random Phase Approximation. Zero-range forces of the Skyrme type and finite-range forces of M3Y and Gogny type are analyzed. It is shown that for the Skyrme forces considered, the tensor effects are sizeable, and tend to increase the spin instability which appears at smaller densities than in the case that the tensor is not taken into account. On the contrary, the tensor contribution of finite range forces to the spin susceptibility is small or negligible for both isospin channels of symmetr...

  10. Measurement of the spin diffusion rate of dipolar order in single crystal calcium fluoride

    E-print Network

    Boutis, Gregory Steven, 1975-

    2002-01-01

    This thesis reports on the first measurement of the spin diffusion rate of a two-spin correlated state, known as dipolar order, in a single crystal of calcium fluoride. The experimental results for the component of the ...

  11. Half-metallic properties, single-spin negative differential resistance, and large single-spin Seebeck effects induced by chemical doping in zigzag-edged graphene nanoribbons

    NASA Astrophysics Data System (ADS)

    Yang, Xi-Feng; Zhou, Wen-Qian; Hong, Xue-Kun; Liu, Yu-Shen; Wang, Xue-Feng; Feng, Jin-Fu

    2015-01-01

    Ab initio calculations combining density-functional theory and nonequilibrium Green's function are performed to investigate the effects of either single B atom or single N atom dopant in zigzag-edged graphene nanoribbons (ZGNRs) with the ferromagnetic state on the spin-dependent transport properties and thermospin performances. A spin-up (spin-down) localized state near the Fermi level can be induced by these dopants, resulting in a half-metallic property with 100% negative (positive) spin polarization at the Fermi level due to the destructive quantum interference effects. In addition, the highly spin-polarized electric current in the low bias-voltage regime and single-spin negative differential resistance in the high bias-voltage regime are also observed in these doped ZGNRs. Moreover, the large spin-up (spin-down) Seebeck coefficient and the very weak spin-down (spin-up) Seebeck effect of the B(N)-doped ZGNRs near the Fermi level are simultaneously achieved, indicating that the spin Seebeck effect is comparable to the corresponding charge Seebeck effect.

  12. A broadband single-chip transceiver for multi-nuclear NMR probes.

    PubMed

    Grisi, Marco; Gualco, Gabriele; Boero, Giovanni

    2015-04-01

    In this article, we present an integrated broadband complementary metal-oxide semiconductor single-chip transceiver suitable for the realization of multi-nuclear pulsed nuclear magnetic resonance (NMR) probes. The realized single-chip transceiver can be interfaced with on-chip integrated microcoils or external LC resonators operating in the range from 1 MHz to 1 GHz. The dimension of the chip is about 1 mm(2). It consists of a radio-frequency (RF) power amplifier, a low-noise RF preamplifier, a frequency mixer, an audio-frequency amplifier, and fully integrated transmit-receive switches. As specific example, we show its use for multi-nuclear NMR spectroscopy. With an integrated coil of about 150 ?m external diameter, a (1)H spin sensitivity of about 1.5 × 10(13) spins/Hz(1/2) is achieved at 7 T. PMID:25933876

  13. A broadband single-chip transceiver for multi-nuclear NMR probes

    NASA Astrophysics Data System (ADS)

    Grisi, Marco; Gualco, Gabriele; Boero, Giovanni

    2015-04-01

    In this article, we present an integrated broadband complementary metal-oxide semiconductor single-chip transceiver suitable for the realization of multi-nuclear pulsed nuclear magnetic resonance (NMR) probes. The realized single-chip transceiver can be interfaced with on-chip integrated microcoils or external LC resonators operating in the range from 1 MHz to 1 GHz. The dimension of the chip is about 1 mm2. It consists of a radio-frequency (RF) power amplifier, a low-noise RF preamplifier, a frequency mixer, an audio-frequency amplifier, and fully integrated transmit-receive switches. As specific example, we show its use for multi-nuclear NMR spectroscopy. With an integrated coil of about 150 ?m external diameter, a 1H spin sensitivity of about 1.5 × 1013 spins/Hz1/2 is achieved at 7 T.

  14. Spin-orbit coupling rule in nuclear and atomic systems

    E-print Network

    Ebran, J -P; Mutschler, A; Vretenar, D

    2015-01-01

    Spin-orbit coupling characterizes quantum systems such as atoms, nuclei, hypernuclei, quarkonia, etc., and is essential for understanding their spectroscopic properties. Depending on the system, the effect of spin-orbit coupling on shell structure is large in nuclei, small in quarkonia, perturbative in atoms. In the standard non-relativistic reduction of the single-particle Dirac equation, we derive a universal rule for the relative magnitude of the spin-orbit effect that applies to very different quantum systems, regardless of whether the spin-orbit coupling originates from the strong or electromagnetic interaction. It is shown that in nuclei the near equality of the mass of the nucleon and the difference between the large repulsive and attractive potentials explains the fact that spin-orbit splittings are comparable to the energy spacing between major shells. For a specific ratio between the particle mass and the effective potential whose gradient determines the spin-orbit force, we predict the occurrence o...

  15. Spin anisotropy effects in dimer single molecule magnets

    NASA Astrophysics Data System (ADS)

    Efremov, Dmitri V.; Klemm, Richard A.

    2006-08-01

    We present a model of homoionic, equal-spin s1 dimer single molecule magnets exhibiting D2h , C2v , or S2 molecular group symmetry, focusing upon the simplest D2h case. The spins within each dimer interact via the Heisenberg and the most general set of four quadratic anisotropic spin interactions with respective strengths J and {Jj} , and with the magnetic induction B . We solve the model exactly for s1=1/2 , and analytically for B along the crystal directions and numerically for other B directions for s1=1 and 5/2, and present M(B) curves at low T for these cases with antiferromagnetic Heisenberg couplings (J<0) . Low- T CV(B) curves for s1=1/2 and electron paramagnetic susceptibility ?(B,?) for s1=1 are also provided. For weakly anisotropic dimers, the Hartree approximation, or strong exchange limit, yields rather simple analytic formulas for M(B) and CV(B) at arbitrary s1 that accurately fit the exact solutions at sufficiently low T or large B . Low- T , large- B formulas for the inelastic neutron-scattering cross section S(B,q,?) and ?(B,?) with arbitrary s1 and B in the Hartree approximation are also given. For antiferromagnetic Heisenberg couplings (J<0) and weak anisotropy interactions (?Jj/J??1) , we provide analytic formulas for the 2s1 level-crossing magnetic inductions Bs,s1lc(?,?) , at which the low- T magnetization M(B) exhibits steps and the low- T specific heat CV(B) exhibits zeroes, surrounded by double peaks of uniform height. Strong anisotropy interactions drastically alter these behaviors, however. Our results are discussed with regard to existing experiments on s1=5/2Fe2 , s1=3/2Cr2 , and s1=1Ni2 dimers, suggesting the presence of single-ion anisotropy in three of them, but apparently without any sizeable anisotropic exchange interactions. Further experiments on single crystals of these and higher-spin dimers are therefore warranted, and we particularly urge further electron paramagnetic resonance and inelastic neutron-scattering experiments to be performed.

  16. Microtesla SABRE enables 10% nitrogen-15 nuclear spin polarization.

    PubMed

    Theis, Thomas; Truong, Milton L; Coffey, Aaron M; Shchepin, Roman V; Waddell, Kevin W; Shi, Fan; Goodson, Boyd M; Warren, Warren S; Chekmenev, Eduard Y

    2015-02-01

    Parahydrogen is demonstrated to efficiently transfer its nuclear spin hyperpolarization to nitrogen-15 in pyridine and nicotinamide (vitamin B(3) amide) by conducting "signal amplification by reversible exchange" (SABRE) at microtesla fields within a magnetic shield. Following transfer of the sample from the magnetic shield chamber to a conventional NMR spectrometer, the (15)N NMR signals for these molecules are enhanced by ?30,000- and ?20,000-fold at 9.4 T, corresponding to ?10% and ?7% nuclear spin polarization, respectively. This method, dubbed "SABRE in shield enables alignment transfer to heteronuclei" or "SABRE-SHEATH", promises to be a simple, cost-effective way to hyperpolarize heteronuclei. It may be particularly useful for in vivo applications because of longer hyperpolarization lifetimes, lack of background signal, and facile chemical-shift discrimination of different species. PMID:25583142

  17. Revisit to Nuclear Spin Temperature of Ammonia in Comets

    NASA Astrophysics Data System (ADS)

    Shinnaka, Yoshiharu; Jehin, E.; Manfroid, J.; Hutsemekers, D.; Arpigny, C.; Kanda, Y.; Kobayashi, H.; Kawakita, H.

    2009-09-01

    Comets had formed from dust and icy materials in the solar nebula 4.6 Gyrs ago. The cometary materials are considered as the most pristine in the solar system and both dust grains and icy materials in comets have been used to investigate the formation conditions of the solar system. One of interesting primordial characters is a nuclear spin temperature (related to an ortho-to-para ratio; OPR) of cometary molecules such as H2O, NH3, etc. The nuclear spin temperatures probably reflect the molecular formation temperatures in the solar nebula (or in the presolar molecular cloud). In this work, we analyzed high dispersion optical spectra of C/2001 Q4 (NEAT), C/2000 WM1 (LINEAR), 88P/Howell, fragments B and C of 73P/Schwassmann-Wachmann 3 and 8P/Tuttle. Our observations were performed by the Ultraviolet and Visual Echelle Spectrograph (UVES) mounted on the Very Large Telescope (VLT) in Chile and the High Dispersion Spectrograph (HDS) mounted on the Subaru telescope in Hawaii. We determined nuclear spin temperatures of NH3 in five comets based on optical spectra of NH2. The nuclear spin temperatures of NH3 can be obtained from OPRs of NH2. We used the (0,9,0) ro-vibronic band at 610nm in this work. Absorption lines (by the telluric atmosphere) and cometary C2 emission lines blended with NH2 emission lines were also taken into account in our analysis. These lines have never been considered in previous studies. The origin of icy materials in the five comets will be discussed based on these results.

  18. Nuclear spins and magnetic moments of some cesium isotopes

    Microsoft Academic Search

    C. Ekström; S. Ingelman; G. Wannberg; M. Skarestad

    1977-01-01

    Using an atomic-beam magnetic resonance apparatus connected on-line with the ISOLDE isotope separator, CERN, hyperfine structure measurements have been performed in the 2S1\\/2 electronic ground state of some cesium isotopes. An on-line oven system which efficiently converts a mass separated ion beam of alkali isotopes to an atomic beam is described in some detail. Experimentally determined nuclear spins of 120,

  19. Nano-magnetic materials: spin crossover compounds vs. single molecule magnets vs. single chain magnets.

    PubMed

    Brooker, Sally; Kitchen, Jonathan A

    2009-09-28

    Brief introductions to spin crossover (SCO), single molecule magnetism (SMM) and single chain magnetism (SCM) are provided. Each section is illustrated by selected examples that have contributed significantly to the development of these fields, including recent efforts to produce materials (films, attachment to surfaces etc.). The advantages and disadvantages of each class of magnetically interesting compound are considered, along with the key challenges that remain to be overcome before such compounds can be used commercially as nanocomponents. This invited perspective article is intended to be easily comprehensible to non-specialists in the field. PMID:19727448

  20. Nuclear states and shapes at high spin. [Good review

    SciTech Connect

    Diamond, R.M.

    1980-08-01

    As angular momentum is added to a nucleus, the balance of forces acting upon it to determine its shape, moment of inertia, mode of rotation, and type of level structure may undergo a series of changes. At relatively low spins a deformed nucleus will rotate collectively, and one may see the effect of Coriolis antipairing in gradually increasing the moment of inertia. Around spin 12 to 16 h-bar there may be an abrupt change (backbending) when a pair of high-j nucleons unpairs and the nucleons align with the axis of rotation; this process allows the nucleus to slow its collective rotation. This process, the start of a sharing of angular momentum between single-particle motion and the collective rotation, gives a lower total energy and corresponds to a change toward triaxiality in the shape of the nucleus. At much higher spins discrete ..gamma..-ray transitions can no longer be observed. This is the regime of continuum spectra; all the information on these high-spin states (to 65 h-bar) is contained in these continuum cascades. Knowledge is accumulating on how to study these spectra, experimentally and theoretically, and new techniques offer promise of revealing a great deal of information about the shapes and properties of very high spin states. 71 references, 34 figures.

  1. Single-spin precessing gravitational waveform in closed form

    NASA Astrophysics Data System (ADS)

    Lundgren, Andrew; O'Shaughnessy, R.

    2014-02-01

    In coming years, gravitational-wave detectors should find black hole-neutron star (BH-NS) binaries, potentially coincident with astronomical phenomena like short gamma ray bursts. These binaries are expected to precess. Gravitational-wave science requires a tractable model for precessing binaries, to disentangle precession physics from other phenomena like modified strong field gravity, tidal deformability, or Hubble flow; and to measure compact object masses, spins, and alignments. Moreover, current searches for gravitational waves from compact binaries use templates where the binary does not precess and are ill-suited for detection of generic precessing sources. In this paper we provide a closed-form representation of the single-spin precessing waveform in the frequency domain by reorganizing the signal as a sum over harmonics, each of which resembles a nonprecessing waveform. This form enables simple analytic calculations of the Fisher matrix for use in template bank generation and coincidence metrics, and jump proposals to improve the efficiency of Markov chain Monte Carlo sampling. We have verified that for generic BH-NS binaries, our model agrees with the time-domain waveform to 2%. Straightforward extensions of the derivations outlined here (and provided in full online) allow higher accuracy and error estimates.

  2. Quasi-Classical Origins of Single Transverse Spin Asymmetries

    NASA Astrophysics Data System (ADS)

    Sievert, Matthew; Kovchegov, Yuri

    2013-10-01

    We consider semi-inclusive deep inelastic scattering and the Drell-Yan process on a transversely-polarized proton at high energies. We model the small- x wave function of the proton using the McLerran-Venugopalan (MV) model, which has been reasonably successful in describing high-energy proton data. The MV model, originally formulated for a heavy ion with a large number ~ A of independent color charges, is a quasi-classical description that should apply to any dense system of color charges, including a proton at very high energies. Here we incorporate spin dependence into the MV framework and analyze several microscopic scattering channels that lead to the generation of a single transverse spin asymmetry. In particular, we study asymmetries mediated by intrinsic orbital angular momentum, asymmetries produced locally by rescattering on the same constituent, and asymmetries that couple to the odderon. This analysis yields a simple, intuitive, quasi-classical picture in which one can understand understand the famous sign-reversal of the Sivers asymmetry between semi-inclusive deep inelastic scattering and the Drell-Yan process. Sponsored in part by DOE Grant No. DE-SC0004286.

  3. Voltage-induced conversion of helical to uniform nuclear spin polarization in a quantum wire

    NASA Astrophysics Data System (ADS)

    Kornich, Viktoriia; Stano, Peter; Zyuzin, Alexander A.; Loss, Daniel

    2015-05-01

    We study the effect of bias voltage on the nuclear spin polarization of a ballistic wire, which contains electrons and nuclei interacting via hyperfine interaction. In equilibrium, the localized nuclear spins are helically polarized due to the electron-mediated Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction. Focusing here on nonequilibrium, we find that an applied bias voltage induces a uniform polarization, from both helically polarized and unpolarized spins available for spin flips. Once a macroscopic uniform polarization in the nuclei is established, the nuclear spin helix rotates with frequency proportional to the uniform polarization. The uniform nuclear spin polarization monotonically increases as a function of both voltage and temperature, reflecting a thermal activation behavior. Our predictions offer specific ways to test experimentally the presence of a nuclear spin helix polarization in semiconducting quantum wires.

  4. Global fitting of single spin asymmetry: an attempt

    SciTech Connect

    Alexey Prokudin,Zhong-Bo Kang

    2012-04-01

    We present an attempt of global analysis of Semi-Inclusive Deep Inelastic Scattering (SIDIS) $\\ell p^\\uparrow \\to \\ell' \\pi X$ data on single spin asymmetries and data on left-right asymmetry $A_N$ in $p^\\uparrow p \\to \\pi X$ in order to simultaneously extract information on Sivers function and twist-three quark-gluon Efremov-Teryaev-Qiu-Sterman (ETQS) function. We explore different possibilities such as node of Sivers function in $x$ or $k_\\perp$ in order to explain ``sign mismatch'' between these functions. We show that $\\pi^\\pm$ SIDIS data and $\\pi^0$ STAR data can be well described in a combined TMD and twist-3 fit, however $\\pi^\\pm$ BRAHMS data are not described in a satisfactory way. This leaves open a question to the solution of the ``sign mismatch''. Possible explanations are then discussed.

  5. Single Transverse-Spin Asymmetries at Large-x

    SciTech Connect

    Brodsky, Stanley J.; Yuan, Feng

    2006-10-24

    The large-x behavior of the transverse-momentum dependent quark distributions is analyzed in the factorization-inspired perturbative QCD framework, particularly for the naive time-reversal-odd quark Sivers function which is responsible for the single transverse-spin asymmetries in various semi-inclusive hard processes. By examining the dominant hard gluon exchange Feynman diagrams, and using the resulting power counting rule, we find that the Sivers function has power behavior (1-x){sup 4} at x {yields} 1, which is one power of (1-x) suppressed relative to the unpolarized quark distribution. These power-counting results provide important guidelines for the parameterization of quark distributions and quark-gluon correlations.

  6. Calculation of TMD Evolution for Transverse Single Spin Asymmetry Measurements

    SciTech Connect

    Mert Aybat, Ted Rogers, Alexey Prokudin

    2012-06-01

    In this letter, we show that it is necessary to include the full treatment of QCD evolution of Transverse Momentum Dependent parton densities to explain discrepancies between HERMES data and recent COMPASS data on a proton target for the Sivers transverse single spin asymmetry in Semi-Inclusive Deep Inelastic Scattering (SIDIS). Calculations based on existing fits to TMDs in SIDIS, and including evolution within the Collins-Soper-Sterman with properly defined TMD PDFs are shown to provide a good explanation for the discrepancy. The non-perturbative input needed for the implementation of evolution is taken from earlier analyses of unpolarized Drell-Yan (DY) scattering at high energy. Its success in describing the Sivers function in SIDIS data at much lower energies is strong evidence in support of the unifying aspect of the QCD TMD-factorization formalism.

  7. Nuclear Spin Maser at Highly Stabilized Low Magnetic Field and Search for Atomic EDM

    SciTech Connect

    Yoshimi, A. [RIKEN Nishina Center, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Asahi, K.; Inoue, T.; Uchida, M.; Hatakeyama, N.; Tsuchiya, M.; Kagami, S. [Department of Physics, Tokyo Institute of Technology, Oh-okayama 2-12-1, Meguro, Tokyo 152-8551 (Japan)

    2009-08-04

    A nuclear spin maser is operated at a low static field through an active feedback scheme based on an optical nuclear spin detection and succeeding spin control by a transverse field application. The frequency stability of this optical-coupling spin maser is improved by installation of a low-noise current source for a solenoid magnet producing a static magnetic field in the maser operation. Experimental devices for application of the maser to EDM experiment are being developed.

  8. Suppression of nuclear spin bath fluctuations in self-assembled quantum dots induced by inhomogeneous strain.

    PubMed

    Chekhovich, E A; Hopkinson, M; Skolnick, M S; Tartakovskii, A I

    2015-01-01

    Interaction with nuclear spins leads to decoherence and information loss in solid-state electron-spin qubits. One particular, ineradicable source of electron decoherence arises from decoherence of the nuclear spin bath, driven by nuclear-nuclear dipolar interactions. Owing to its many-body nature nuclear decoherence is difficult to predict, especially for an important class of strained nanostructures where nuclear quadrupolar effects have a significant but largely unknown impact. Here, we report direct measurement of nuclear spin bath coherence in individual self-assembled InGaAs/GaAs quantum dots: spin-echo coherence times in the range 1.2-4.5?ms are found. Based on these values, we demonstrate that strain-induced quadrupolar interactions make nuclear spin fluctuations much slower compared with lattice-matched GaAs/AlGaAs structures. Our findings demonstrate that quadrupolar effects can potentially be used to engineer optically active III-V semiconductor spin-qubits with a nearly noise-free nuclear spin bath, previously achievable only in nuclear spin-0 semiconductors, where qubit network interconnection and scaling are challenging. PMID:25704639

  9. Suppression of nuclear spin bath fluctuations in self-assembled quantum dots induced by inhomogeneous strain

    PubMed Central

    Chekhovich, E.A.; Hopkinson, M.; Skolnick, M.S.; Tartakovskii, A.I.

    2015-01-01

    Interaction with nuclear spins leads to decoherence and information loss in solid-state electron-spin qubits. One particular, ineradicable source of electron decoherence arises from decoherence of the nuclear spin bath, driven by nuclear–nuclear dipolar interactions. Owing to its many-body nature nuclear decoherence is difficult to predict, especially for an important class of strained nanostructures where nuclear quadrupolar effects have a significant but largely unknown impact. Here, we report direct measurement of nuclear spin bath coherence in individual self-assembled InGaAs/GaAs quantum dots: spin-echo coherence times in the range 1.2–4.5?ms are found. Based on these values, we demonstrate that strain-induced quadrupolar interactions make nuclear spin fluctuations much slower compared with lattice-matched GaAs/AlGaAs structures. Our findings demonstrate that quadrupolar effects can potentially be used to engineer optically active III-V semiconductor spin-qubits with a nearly noise-free nuclear spin bath, previously achievable only in nuclear spin-0 semiconductors, where qubit network interconnection and scaling are challenging. PMID:25704639

  10. Magnetization process of a single magnetic ring detected by nonlocal spin valve measurement

    E-print Network

    Otani, Yoshichika

    Magnetization process of a single magnetic ring detected by nonlocal spin valve measurement T of a 200-nm-wide Permalloy ring using a nonlocal spin-valve measurement technique in a lateral geometry state using lateral spin-valve geometry.13­15 The chirality is found to be easily determined from

  11. Imaging nuclear spins weakly coupled to a probe paramagnetic center

    NASA Astrophysics Data System (ADS)

    Laraoui, Abdelghani; Pagliero, Daniela; Meriles, Carlos A.

    2015-05-01

    Optically detected paramagnetic centers in wide-band-gap semiconductors are emerging as a promising platform for nanoscale metrology at room temperature. Of particular interest are applications where the center is used as a probe to interrogate other spins that cannot be observed directly. Using the nitrogen-vacancy (NV) center in diamond as a model system, we propose a strategy to determine the spatial coordinates of weakly coupled nuclear spins. The central idea is to label the target nucleus with a spin polarization that depends on its spatial location, which is subsequently revealed by making this polarization flow back to the NV for readout. Using extensive analytical and numerical modeling, we show that the technique can attain high spatial resolution depending on the NV lifetime and target spin location. No external magnetic field gradient is required, which circumvents complications resulting from changes in the direction of the applied magnetic field, and considerably simplifies the required instrumentation. Extensions of the present technique may be adapted to pinpoint the locations of other paramagnetic centers in the NV vicinity or to yield information on dynamical processes in molecules on the diamond surface.

  12. One dimensional electron spin imaging for single spin detection and manipulation using a gradient field 

    E-print Network

    Shin, Chang-Seok

    2009-05-15

    and manipulate the spin states is also required for spin based quantum information processing. Although optical detection techniques, such as optically detected electron spin resonance (ESR) seem very powerful in these contexts, multiple molecules in the focal...

  13. Self-Sustaining Resistance Oscillations by Electron-Nuclear Spin Coupling in Mesoscopic Quantum Hall Systems

    NASA Astrophysics Data System (ADS)

    Yusa, G.; Hashimoto, K.; Muraki, K.; Saku, T.; Hirayama, Y.

    2005-06-01

    We study electron-nuclear spin coupling implemented in mesoscopic fractional quantum Hall (FQH) devices. We find that longitudinal resistance in such systems oscillates with a period of several hundreds of seconds driven by a constant voltage instead of a constant current. The anomalous behavior suggests that an average nuclear spin polarization self-sustainingly oscillates between randomized and polarized states, which reveal nonlinear nature of the mesoscopic electron-nuclear spin coupled systems.

  14. Self-sustaining resistance oscillations: Electron-nuclear spin coupling in mesoscopic quantum Hall devices

    NASA Astrophysics Data System (ADS)

    Yusa, G.; Hashimoto, K.; Muraki, K.; Saku, T.; Hirayama, Y.

    2004-04-01

    We study electron-nuclear spin coupled systems implemented in mesoscopic fractional quantum Hall devices. We find that longitudinal resistance in such systems, oscillates with a period of several hundreds of seconds driven by a constant voltage instead of a constant current. The anomalous behavior suggests that an average nuclear spin polarization self-sustainingly oscillates between randomized and polarized states, which reveal the nonlinear nature of the mesoscopic electron-nuclear spin coupled systems.

  15. Stable Three-Axis Nuclear Spin Gyroscope in Diamond

    E-print Network

    Ashok Ajoy; Paola Cappellaro

    2012-05-07

    We propose a sensitive and stable three-axis gyroscope in diamond. We achieve high sensitivity by exploiting the long coherence time of the N14 nuclear spin associated with the Nitrogen-Vacancy center in diamond, and the efficient polarization and measurement of its electronic spin. While the gyroscope is based on a simple Ramsey interferometry scheme, we use coherent control of the quantum sensor to improve its coherence time as well as its robustness against long-time drifts, thus achieving a very robust device with a resolution of 0.5mdeg/s/(Hz mm^3)^(1/2). In addition, we exploit the four axes of delocalization of the Nitrogen-Vacancy center to measure not only the rate of rotation, but also its direction, thus obtaining a compact three-axis gyroscope.

  16. Radioactive nuclear beams and the North American IsoSpin Laboratory (ISL) initiative

    SciTech Connect

    Casten, R.F.

    1992-12-01

    Radioactive nuclear beams (RNBs) offer exciting new research opportunities in fields as diverse as nuclear structure, nuclear reactions, astrophysics atomic, materials, and applied science. Their realization in new accelerator complexes also offers important technical challenges. Some of the nuclear physics possibilities afforded by RNBs, with emphasis on low spin nuclear structure, are discussed, accompanied by an outline of the ISL initiative and its status.

  17. Radioactive nuclear beams and the North American IsoSpin Laboratory (ISL) initiative

    SciTech Connect

    Casten, R.F.

    1992-01-01

    Radioactive nuclear beams (RNBs) offer exciting new research opportunities in fields as diverse as nuclear structure, nuclear reactions, astrophysics atomic, materials, and applied science. Their realization in new accelerator complexes also offers important technical challenges. Some of the nuclear physics possibilities afforded by RNBs, with emphasis on low spin nuclear structure, are discussed, accompanied by an outline of the ISL initiative and its status.

  18. Multiple Reflection Effect on Spin-Transfer Torque Dynamics in Spin Valves with a Single or Dual Polarizer

    NASA Astrophysics Data System (ADS)

    Zhu, Weiwei; Zhang, Zongzhi; Zhang, Jianwei; Liu, Yaowen

    2015-04-01

    In this paper, spin-dependent multiple reflection effect on spin-transfer torque (STT) has been theoretically and numerically studied in a spin valve nanopillar with a single or dual spin-polarizer. By using a scattering matrix method, we formulate an analytical expression of STT that contains the multiple interfacial reflection effect. It is found that the multiple reflections could enhance the STT efficiency and reduce the critical switching current. The STT efficiency depends on the spin polarization of both the free layer and polarizer. In the nanopillars with a dual spin polarizer, the multiple reflections would cause an asymmetric frequency dependence on the applied current, albeit exactly the same parameters are used in all three ferromagnetic layers, indicating that the frequency in the negative current varies much faster than that in the positive case.

  19. Tunable spin loading and T1 of a silicon spin qubit measured by single-shot readout.

    PubMed

    Simmons, C B; Prance, J R; Van Bael, B J; Koh, Teck Seng; Shi, Zhan; Savage, D E; Lagally, M G; Joynt, R; Friesen, Mark; Coppersmith, S N; Eriksson, M A

    2011-04-15

    We demonstrate single-shot readout of a silicon quantum dot spin qubit, and we measure the spin relaxation time T1. We show that the rate of spin loading can be tuned by an order of magnitude by changing the amplitude of a pulsed-gate voltage, and the fraction of spin-up electrons loaded can also be controlled. This tunability arises because electron spins can be loaded through an orbital excited state. Using a theory that includes excited states of the dot and energy-dependent tunneling, we find that a global fit to the loading rate and spin-up fraction is in good agreement with the data. PMID:21568595

  20. Mapping spin coherence of a single rare-earth ion in a crystal onto a single photon polarization state

    E-print Network

    Roman Kolesov; Kangwei Xia; Rolf Reuter; Rainer Stoehr; Tugrul Inal; Petr Siyushev; Joerg Wrachtrup

    2013-01-22

    We report on optical detection of a single photostable Ce3+ ion in an yttrium aluminium garnet (YAG) crystal and on its magneto-optical properties at room temperature. The quantum state of an electron spin of the emitting level of cerium ion in YAG can be initialized by circularly polarized laser pulse. Furthermore, its quantum state can be read out by observing temporal behaviour of circularly polarized fluorescence of the ion. This implies direct mapping of the spin quantum state of Ce3+ ion onto the polarization state of the emitted photon and represents one-way quantum interface between a single spin and a single photon.

  1. Atomic-resolution single-spin magnetic resonance detection concept based on tunneling force microscopy

    NASA Astrophysics Data System (ADS)

    Payne, A.; Ambal, K.; Boehme, C.; Williams, C. C.

    2015-05-01

    A study of a force detected single-spin magnetic resonance measurement concept with atomic spatial resolution is presented. The method is based upon electrostatic force detection of spin-selection rule controlled single-electron tunneling between two electrically isolated paramagnetic states. Single-spin magnetic resonance detection is possible by measuring the force detected tunneling charge noise on and off spin resonance. Simulation results of this charge noise, based upon physical models of the tunneling and spin physics, are directly compared to measured atomic force microscopy system noise. The results show that the approach could provide single-spin measurement of electrically isolated qubit states with atomic spatial resolution at room temperature.

  2. Nuclear Spin Polarization of Phosphorus Donors in Silicon. Direct Evidence from 31P-Nuclear Magnetic Resonance

    NASA Astrophysics Data System (ADS)

    Gumann, Patryk; Ramanathan, Chandrasekhar; Patange, Om; Moussa, Osama; Thewalt, Mike; Riemann, Helge; Abrosimov, Nikolay; Becker, Peter; Pohl, Hans-Joachim; Itoh, Kohei; Cory, David G.

    2014-03-01

    We experimentally demonstrate the optical hyperpolarization and coherent control of 31P, nuclear spins in single crystal silicon via the inductive readout of the nuclear magnetic resonance (NMR) signal of 31P at a concentration of 1.5 x 1015 cc-1. The obtained polarization is sufficient the 31P spin polarization of 1.17 x 1015 in a 10 mm x 10 mm sample, observed in one FID with signal-to-noise ration of 113. The linewidth is 800 Hz. The Hahn echo pulse sequence reveals a 31P T2 time of 0.42 s at 1.6 K, which was extended by the Carr Purcell cycle to 1.2 s at the same temperature. The maximum build-up of the nuclear polarization was achieved within ~577 seconds, at 4.2 K, in 6.7 T, using optical excitations provided by an infra-red laser. This work has been supported by CERC Canada.

  3. Nuclear spin-spin coupling in a van der Waals-bonded system: xenon dimer.

    PubMed

    Vaara, Juha; Hanni, Matti; Jokisaari, Jukka

    2013-03-14

    Nuclear spin-spin coupling over van der Waals bond has recently been observed via the frequency shift of solute protons in a solution containing optically hyperpolarized (129)Xe nuclei. We carry out a first-principles computational study of the prototypic van der Waals-bonded xenon dimer, where the spin-spin coupling between two magnetically non-equivalent isotopes, J((129)Xe - (131)Xe), is observable. We use relativistic theory at the four-component Dirac-Hartree-Fock and Dirac-density-functional theory levels using novel completeness-optimized Gaussian basis sets and choosing the functional based on a comparison with correlated ab initio methods at the nonrelativistic level. J-coupling curves are provided at different levels of theory as functions of the internuclear distance in the xenon dimer, demonstrating cross-coupling effects between relativity and electron correlation for this property. Calculations on small Xe clusters are used to estimate the importance of many-atom effects on J((129)Xe - (131)Xe). Possibilities of observing J((129)Xe - (131)Xe) in liquid xenon are critically examined, based on molecular dynamics simulation. A simplistic spherical model is set up for the xenon dimer confined in a cavity, such as in microporous materials. It is shown that the on the average shorter internuclear distance enforced by the confinement increases the magnitude of the coupling as compared to the bulk liquid case, rendering J((129)Xe - (131)Xe) in a cavity a feasible target for experimental investigation. PMID:23514495

  4. Correlated internal motions and nuclear spin relaxation in lamellar mesophase

    NASA Astrophysics Data System (ADS)

    Caniparoli, J. P.; Grassi, A.; Chachaty, C.

    A model of correlated internal motions has been developed for investigating, by nuclear spin relaxation, the dynamical behaviour of a small flexible molecule solubilized in a lamellar mesophase. This model, which involves the population of the molecular conformers and the transition rates among them, has been illustrated by the deuteron longitudinal relaxation of a diluted perdeuterated butanol solution in the sodium dibutylphosphate/water lamellar phase. Having derived the conformer populations from the quadrupolar splittings, the reorientational diffusion coefficients were obtained by a minimization procedure from the temperature dependence of the deuteron T1 relaxation times at 46 and 77 MHz.

  5. Polarization Dependence of the Spin-Density-Wave Excitations in Single-Domain Chromium

    SciTech Connect

    Boeni, P. [Labor fuer Neutronenstreuung, Villigen PSI (Switzerland); Sternlieb, B.J.; Shirane, G. [Brookhaven National Lab., Upton, NY (United States); Roessli, B.; Werner, S.A. [Institut Laue Langevin, Grenoble Cedex (France); Lorenzo, J.E. [Laboratoire de Crystallographie, CNRS, Grenoble (France)

    1997-12-31

    A polarised neutron scattering experiment has been performed on a single-Q, single domain sample of Cr in a magnetic field of 4 T in the transverse spin-density-wave phase. It is confirmed that the longitudinal fluctuations are enhanced for energy transfers E {lt} 8 meV similarly as in the longitudinal spin-density-wave phase. The spin wave modes with deltaS parallel and perpendicular to Q are isotropic within the E-range investigated.

  6. Voltage tunability of single-spin states in a quantum dot.

    PubMed

    Bennett, Anthony J; Pooley, Matthew A; Cao, Yameng; Sköld, Niklas; Farrer, Ian; Ritchie, David A; Shields, Andrew J

    2013-01-01

    Single spins in the solid state offer a unique opportunity to store and manipulate quantum information, and to perform quantum-enhanced sensing of local fields and charges. Optical control of these systems using techniques developed in atomic physics has yet to exploit all the advantages of the solid state. Here we demonstrate voltage tunability of the spin energy-levels in a single quantum dot by modifying how spins sense magnetic field. We find that the in-plane g-factor varies discontinuously for electrons, as more holes are loaded onto the dot. In contrast, the in-plane hole g-factor varies continuously. The device can change the sign of the in-plane g-factor of a single hole, at which point an avoided crossing is observed in the two spin eigenstates. This is exactly what is required for universal control of a single spin with a single electrical gate. PMID:23443550

  7. Nuclear spin-dependent parity nonconservation in diatomic molecules

    NASA Astrophysics Data System (ADS)

    Murphree, Dennis Haaga, Jr.

    Nuclear spin-dependent parity nonconserving phenomena produce effects that are relevant to particle, nuclear, and atomic physics. They unite these increasingly disparate disciplines via the subtle effects of the weak force. Currently, weak interactions between nucleons present at best a confusing picture, and neutral weak coupling of leptons to baryons, even at high energy, is one of the most poorly characterized aspects of the Standard Model. Perhaps surprisingly, one of the most effective laboratories for studying parity violation is the diatomic molecule. The naturally close spacing of molecular hyperfine-rotational levels, which can be Zeeman shifted even closer to degeneracy, allows small parity violating effects to be enhanced dramatically. Here we describe the beginning of our experimental program to study nuclear spin-dependent parity nonconservation (NSD-PNC) using a beam of diatomic free radicals. Specifically, we seek to measure weak matrix elements connecting hyperfine-rotational states in a series of molecules, beginning with barium fluoride. Our experimental technique is based on a Stark interference method: we look for asymmetries in transitions that depend on the sign of an applied electric field. A key element in the experimental program is the magnetic field used to Zeeman shift the levels in our molecules to near crossing. Carefully controlling both the strength and uniformity of this field is critical to the success of the experiment. In order to measure the field over the wide range of values required by our experiment, both a completely novel nuclear magnetic resonance probe, as well as a unique field shimming apparatus and algorithm, were developed. A second important element in the program is the ability to detect the states of our molecules with as high a signal to noise as possible. To that end a new detection method based on a two-photon transition was developed. Both of these areas, which constitute the bulk of the author's contribution to the experimental program, are described in detail.

  8. Nuclear spin-lattice relaxation times of metallic antimony at low temperatures

    NASA Astrophysics Data System (ADS)

    Genio, E. B.; Xu, J.; Lang, T.; Ihas, G. G.; Sullivan, N. S.

    1995-11-01

    We have used pulsed Nuclear Quadrupole Resonance (NQR) techniques to measure the nuclear spin-lattice relaxation times in antimony at low temperatures. High quality echoes with strong signal/noise ratios were only observed for finely powdered samples of high purity (99.9999%). The samples were carefully annealed and diluted with fine silica to below the percolation limit to minimize RF heating. The powder mixture was immersed in liquid3He to ensure good thermal contact to a sintered silver heat exchanger attached to a copper nuclear demagnetization refrigerator. We report the temperature dependence of the nuclear spin-lattice relaxation times for the multiple level nuclear spin system.

  9. Free-induction decay and envelope modulations in a narrowed nuclear spin bath

    NASA Astrophysics Data System (ADS)

    Coish, W. A.; Fischer, Jan; Loss, Daniel

    2010-04-01

    We evaluate free-induction decay for the transverse components of a localized electron spin coupled to a bath of nuclear spins via the Fermi-contact hyperfine interaction. Our perturbative treatment is valid for special (narrowed) bath initial conditions and when the Zeeman energy of the electron b exceeds the total hyperfine coupling constant A : b>A . Using one unified and systematic method, we recover previous results reported at short and long times using different techniques. We find an unexpected modulation of the free-induction-decay envelope, which is present even for a purely isotropic hyperfine interaction without spin echoes and for a single nuclear species. We give subleading corrections to the decoherence rate, and show that, in general, the decoherence rate has a nonmonotonic dependence on electron Zeeman splitting, leading to a pronounced maximum. These results illustrate the limitations of methods that make use of leading-order effective Hamiltonians and re-exponentiation of short-time expansions for a strongly interacting system with non-Markovian (history-dependent) dynamics.

  10. Coherent control of single spins in silicon carbide at room temperature

    NASA Astrophysics Data System (ADS)

    Widmann, Matthias; Lee, Sang-Yun; Rendler, Torsten; Son, Nguyen Tien; Fedder, Helmut; Paik, Seoyoung; Yang, Li-Ping; Zhao, Nan; Yang, Sen; Booker, Ian; Denisenko, Andrej; Jamali, Mohammad; Momenzadeh, S. Ali; Gerhardt, Ilja; Ohshima, Takeshi; Gali, Adam; Janzén, Erik; Wrachtrup, Jörg

    2015-02-01

    Spins in solids are cornerstone elements of quantum spintronics. Leading contenders such as defects in diamond or individual phosphorus dopants in silicon have shown spectacular progress, but either lack established nanotechnology or an efficient spin/photon interface. Silicon carbide (SiC) combines the strength of both systems: it has a large bandgap with deep defects and benefits from mature fabrication techniques. Here, we report the characterization of photoluminescence and optical spin polarization from single silicon vacancies in SiC, and demonstrate that single spins can be addressed at room temperature. We show coherent control of a single defect spin and find long spin coherence times under ambient conditions. Our study provides evidence that SiC is a promising system for atomic-scale spintronics and quantum technology.

  11. Spin-pseudospin intertwined excitation at the ν = 1 bilayer quantum Hall state investigated by nuclear-spin relaxation

    NASA Astrophysics Data System (ADS)

    Tsuda, S.; Terasawa, D.; Nguyen, M. H.; Fukuda, A.; Zheng, Y. D.; Arai, T.; Sawada, A.; Ezawa, Z. F.

    2013-12-01

    We investigate the electron spin degree of freedom at the imbalanced density bilayer ? = 1 quantum Hall states using the resistively detected nuclear-spin-lattice relaxation rate 1/T1. Our measurements reveal a continuous change in 1/T1 for ? = 1 to 0, suggesting that the balanced density ? = 1 state also exhibits electron-spin fluctuations. Moreover, the value of 1/T1 in the back layer (the layer from which electrons are transferred to the front layer) increases at intermediate density imbalance states. This indicates that the low-energy electron-spin mode, similar to a mode observed in Skyrmion crystals, might extend across the two layers.

  12. Single Transverse Spin Asymmetries in Semi-inclusive Deep Inelastic Scattering in a Spin-1 Diquark Model

    E-print Network

    Narinder Kumar; Harleen Dahiya

    2015-04-15

    The observed results for the azimuthal single spin asymmetries (SSAs) of the proton, measured in the semi-inclusive deep inelastic scattering (SIDIS), can be explained by the final-state interaction (FSI) from the gluon exchange between the outgoing quark and the target spectator system. SSAs require a phase difference between two amplitudes coupling the target with opposite spins to the same final state. We have used the model of light front wave functions (LFWFs) consisting of a spin-$\\frac{1}{2}$ system as a composite of a spin-$\\frac{1}{2}$ fermion and a spin-1 vector boson to estimate the SSAs. The implications of such a model have been investigated in detail by considering different coupling constants. The FSIs also produce a complex phase which can be included in the LFWFs to calculate the Sivers and Boer-Mulders distribution functions of the nucleon.

  13. Nuclear Spin Locking and Extended Two-Electron Spin Decoherence Time in an InAs Quantum Dot Molecule

    NASA Astrophysics Data System (ADS)

    Chow, Colin; Ross, Aaron; Steel, Duncan; Sham, L. J.; Bracker, Allan; Gammon, Daniel

    2015-03-01

    The spin eigenstates for two electrons confined in a self-assembled InAs quantum dot molecule (QDM) consist of the spin singlet state, S, with J = 0 and the triplet states T-, T0 and T+, with J = 1. When a transverse magnetic field (Voigt geometry) is applied, the two-electron system can be initialized to the different states with appropriate laser excitation. Under the excitation of a weak probe laser, non-Lorentzian lineshapes are obtained when the system is initialized to either T- or T+, where T- results in a ``resonance locking'' lineshape while T+ gives a ``resonance avoiding '' lineshape: two different manifestations of hysteresis showing the importance of memory in the system. These observations signify dynamic nuclear spin polarization (DNSP) arising from a feedback mechanism involving hyperfine interaction between lattice nuclei and delocalized electron spins, and Overhauser shift due to nuclear spin polarization. Using pump configurations that generate coherent population trapping, the isolation of the electron spin from the optical excitation shows the stabilization of the nuclear spin ensemble. The dark-state lineshape measures the lengthened electron spin decoherence time, from 1 ns to 1 ?s. Our detailed spectra highlight the potential of QDM for realizing a two-qubit gate. This work is supported by NSF, ARO, AFOSR, DARPA, and ONR.

  14. Self-sustained current oscillation and nuclear spin effects in quantum dots

    NASA Astrophysics Data System (ADS)

    Ono, Keiji; Yamaguchi, Shinpei; Tarucha, Seigo

    2004-05-01

    Hyperfine coupling of electron spins to nuclear spins is studied for a GaAs-based double quantum dot in the spin blockade. A current flowing through the double dot shows time-dependent oscillations with a period of as long as 200 sec.

  15. Quantum nondemolition measurement of a single electron spin in a quantum dot

    E-print Network

    Mitsuro Sugita; Susumu Machida; Yoshihisa Yamamoto

    2003-01-15

    We propose a scheme for the quantum nondemolition (QND) measurement of a single electron spin in a single quantum dot (QD). Analytical expressions are obtained for the optical Faraday effect between a quantum dot exciton and microcavity field. The feasibility of the QND measurement of a single electron spin is discussed for a GaAs/AlAs microcavity with an InAs QD.

  16. Nearly Perfect Spin Filter, Spin Valve and Negative Differential Resistance Effects in a Fe4-based Single-molecule Junction

    PubMed Central

    Zu, Fengxia; Liu, Zuli; Yao, Kailun; Gao, Guoying; Fu, Huahua; Zhu, Sicong; Ni, Yun; Peng, Li

    2014-01-01

    The spin-polarized transport in a single-molecule magnet Fe4 sandwiched between two gold electrodes is studied, using nonequilibrium Green's functions in combination with the density-functional theory. We predict that the device possesses spin filter effect (SFE), spin valve effect (SVE), and negative differential resistance (NDR) behavior. Moreover, we also find that the appropriate chemical ligand, coupling the single molecule to leads, is a key factor for manipulating spin-dependent transport. The device containing the methyl ligand behaves as a nearly perfect spin filter with efficiency approaching 100%, and the transport is dominated by transmission through the Fe4 metal center. However, in the case of phenyl ligand, the spin filter effect seems to be reduced, but the spin valve effect is significantly enhanced with a large magnetoresistance ratio, reaching 1800%. This may be attributed to the blocking effect of the phenyl ligands in mediating transport. Our findings suggest that such a multifunctional molecular device, possessing SVE, NDR and high SFE simultaneously, would be an excellent candidate for spintronics of molecular devices. PMID:24787446

  17. Nuclear spin optical rotation and Faraday effect in gaseous and liquid water.

    PubMed

    Pennanen, Teemu S; Ikäläinen, Suvi; Lantto, Perttu; Vaara, Juha

    2012-05-14

    Nuclear spin optical rotation (NSOR) of linearly polarized light, due to the nuclear spins through the Faraday effect, provides a novel probe of molecular structure and could pave the way to optical detection of nuclear magnetization. We determine computationally the effects of the liquid medium on NSOR and the Verdet constant of Faraday rotation (arising from an external magnetic field) in water, using the recently developed theory applied on a first-principles molecular dynamics trajectory. The gas-to-liquid shifts of the relevant antisymmetric polarizability and, hence, NSOR magnitude are found to be -14% and -29% for (1)H and (17)O nuclei, respectively. On the other hand, medium effects both enhance the local electric field in water and, via bulk magnetization, the local magnetic field. Together these two effects partially cancel the solvation influence on the single-molecular property. We find a good agreement for the hydrogen NSOR with a recent pioneering experiment on H(2)O(l). PMID:22583295

  18. Coherent control of two nuclear spins using the anisotropic hyperfine interaction

    E-print Network

    Yingjie Zhang; Colm A. Ryan; Raymond Laflamme; Jonathan Baugh

    2011-09-02

    We demonstrate coherent control of two nuclear spins mediated by the magnetic resonance of a hyperfine-coupled electron spin. This control is used to create a double nuclear coherence in one of the two electron spin manifolds, starting from an initial thermal state, in direct analogy to the creation of an entangled (Bell) state from an initially pure unentangled state. We identify challenges and potential solutions to obtaining experimental gate fidelities useful for quantum information processing in this type of system.

  19. Quantum Information Processing with Large Nuclear Spins in GaAs Semiconductors

    Microsoft Academic Search

    Michael N. Leuenberger; Daniel Loss; Martino Poggio; David D. Awschalom

    2002-01-01

    We propose an implementation for quantum information processing based on coherent manipulations of nuclear spins I=3\\/2 in GaAs semiconductors. We describe theoretically an NMR method which involves multiphoton transitions and which exploits the nonequidistance of nuclear spin levels due to quadrupolar splittings. Starting from known spin anisotropies we derive effective Hamiltonians in a generalized rotating frame, valid for arbitrary I,

  20. Nuclear Spin-Dependent Parity Nonconservation in Diatomic Molecules

    NASA Astrophysics Data System (ADS)

    Rahmlow, David; Murphree, Dennis; Cahn, Sidney; Demille, David; Deveney, Edward; Paolino, Richard; Kozlov, Misha

    2008-05-01

    Nuclear spin-dependent parity nonconservation (NSD-PNC) effects arise from couplings of the Z0 boson (parameterized by the electroweak coupling constants C2P,N) and from the interaction of electrons with the nuclear anapole moment, a parity-odd magnetic moment. The effects of the anapole moment scale with the nucleon number A of the nucleus as A^2/3, while the Z0 coupling is independent of A; the former will be the dominant source of NSD-PNC in nuclei with A > 20. To date, the most precise result on NSD-PNC comes from a measurement of the hyperfine dependence of atomic PNC in ^133Cs. However, the effects of NSD-PNC can be dramatically enhanced in diatomic molecules. We outline an experimental program to take advantage of this enhancement. We have identified over ten suitable molecules; from measurements on the nuclei in these molecules we can extract the relative contributions of the anapole moment and the electroweak Z0 couplings. This will increase the available data on nuclear anapole moments, as well as reduce the uncertainties in current measurements of C2N and C2P. We report on the design of our pulsed molecular beam experiment and the current status of our efforts.

  1. Nuclear Spin-Dependent Parity Nonconservation in Diatomic Molecules

    NASA Astrophysics Data System (ADS)

    Rahmlow, David; Demille, David; Cahn, Sidney; Murphree, Dennis; Barry, John; Steinecker, Matthew; Yale, Christopher; Deveney, Edward; Paolino, Richard; Kozolv, Mikhail

    2009-05-01

    Nuclear spin-dependent parity nonconservation (NSD-PNC) effects arise from couplings of the Z0 boson (parameterized by the electroweak coupling constants C2P,N) and from the interaction of electrons with the nuclear anapole moment, a parity-odd magnetic moment. The latter scales with the nucleon number A of the nucleus as A^2/3, while the Z0 coupling is independent of A; the former will be the dominant source of NSD-PNC in nuclei with A>20. The most precise result on NSD-PNC to date comes from a measurement of the hyperfine dependence of atomic PNC in ^133Cs, but this effect can be dramatically enhanced in diatomic molecules. We outline an experimental program to take advantage of this enhancement with over ten suitable molecules with which we can extract the relative contributions of the anapole moment and the electroweak Z0 couplings. This will increase the available data on nuclear anapole moments, as well as reduce the uncertainties in current measurements of C2N and C2P. We report on improvements in the design of our pulsed molecular beam experiment and the current status of our efforts.

  2. Nuclear Spin-Dependent Parity Violation in Diatomic Molecules

    NASA Astrophysics Data System (ADS)

    Ammon, Jeffrey; Cahn, Sidney; Kirilov, Emil; Demille, David; Kozlov, Mikhail; Paolino, Richard

    2012-06-01

    Nuclear spin-dependent parity violation (NSD-PV) effects arise from exchange of the Z^0 boson (parametrized by the electroweak coupling constants C2P,N) between electrons and the nucleus, and from the interaction of electrons with the nuclear anapole moment, a parity-odd magnetic moment. The latter scales with the nucleon number A of the nucleus as A^3/2, while the Z^0 coupling is independent of A; the former will be the dominant source of NSD-PV in nuclei with A greater than 20. NSD-PV effects can be dramatically amplified in diatomic molecules by bringing two levels of opposite parity close to degeneracy in a strong magnetic field. This opens the prospect for measurements across a broad range of nuclei. As a precursor to the measurement of the nuclear anapole moment of ^137Ba, we have experimentally observed and characterized opposite-parity level crossings in ^138BaF. These are found to be in excellent agreement with parameter-free predictions and indicate that the sensitivity necessary for NSD-PV measurements should be within reach.

  3. Single-Transverse Spin Asymmetry in Dijet Correlations at Hadron Colliders

    E-print Network

    C. J. Bomhof; P. J. Mulders; W. Vogelsang; F. Yuan

    2007-01-31

    We present a phenomenological study of the single-transverse spin asymmetry in azimuthal correlations of two jets produced nearly "back-to-back" in pp collisions at RHIC. We properly take into account the initial- and final-state interactions of partons that can generate this asymmetry in QCD hard-scattering. Using distribution functions fitted to the existing single-spin data, we make predictions for various weighted single-spin asymmetries in dijet correlations that are now readily testable at RHIC.

  4. Single-photon spin-orbit entanglement violating a Bell-like inequality

    E-print Network

    Lixiang Chen; Weilong She

    2010-01-07

    Single photons emerging from q-plates (or Pancharatnam-Berry phase optical element) exhibit entanglement in the degrees of freedom of spin and orbital angular momentum. We put forward an experimental scheme for probing the spin-orbit correlations of single photons. It is found that the Clauser-Horne-Shimony-Holt (CHSH) parameter S for the single-photon spin-orbit entangled state could be up to 2.828, evidently violating the Bell-like inequality and thus invalidating the noncontextual hidden variable (NCHV) theories.

  5. Selective Rotational Excitation of Molecular Isotopes and Nuclear Spin Isomers

    E-print Network

    Sharly Fleischer; Ilya. Sh. Averbukh; Yehiam Prior

    2007-02-15

    Following excitation by a strong ultra-short laser pulse, molecules develop coordinated rotational motion, exhibiting transient alignment along the direction of the laser electric field, followed by periodic full and fractional revivals that depend on the molecular rotational constants. In mixtures, the different species undergo similar rotational dynamics, all starting together but evolving differently with each demonstrating its own periodic revival cycles. For a bimolecular mixture of linear molecules, at predetermined times, one species may attain a maximally aligned state while the other is anti-aligned (i.e. molecular axes are confined in a plane perpendicular to the laser electric field direction). By a properly timed second laser pulse, the rotational excitation of the undesired species may be almost completely removed leaving only the desired species to rotate and periodically realign, thus facilitating further selective manipulations by polarized light. In this paper, such double excitation schemes are demonstrated for mixtures of molecular isotopes (isotopologues) and for nuclear spin isomers.

  6. A 3D-printed high power nuclear spin polarizer.

    PubMed

    Nikolaou, Panayiotis; Coffey, Aaron M; Walkup, Laura L; Gust, Brogan M; LaPierre, Cristen D; Koehnemann, Edward; Barlow, Michael J; Rosen, Matthew S; Goodson, Boyd M; Chekmenev, Eduard Y

    2014-01-29

    Three-dimensional printing with high-temperature plastic is used to enable spin exchange optical pumping (SEOP) and hyperpolarization of xenon-129 gas. The use of 3D printed structures increases the simplicity of integration of the following key components with a variable temperature SEOP probe: (i) in situ NMR circuit operating at 84 kHz (Larmor frequencies of (129)Xe and (1)H nuclear spins), (ii) <0.3 nm narrowed 200 W laser source, (iii) in situ high-resolution near-IR spectroscopy, (iv) thermoelectric temperature control, (v) retroreflection optics, and (vi) optomechanical alignment system. The rapid prototyping endowed by 3D printing dramatically reduces production time and expenses while allowing reproducibility and integration of "off-the-shelf" components and enables the concept of printing on demand. The utility of this SEOP setup is demonstrated here to obtain near-unity (129)Xe polarization values in a 0.5 L optical pumping cell, including ?74 ± 7% at 1000 Torr xenon partial pressure, a record value at such high Xe density. Values for the (129)Xe polarization exponential build-up rate [(3.63 ± 0.15) × 10(-2) min(-1)] and in-cell (129)Xe spin-lattice relaxation time (T1 = 2.19 ± 0.06 h) for 1000 Torr Xe were in excellent agreement with the ratio of the gas-phase polarizations for (129)Xe and Rb (PRb ? 96%). Hyperpolarization-enhanced (129)Xe gas imaging was demonstrated with a spherical phantom following automated gas transfer from the polarizer. Taken together, these results support the development of a wide range of chemical, biochemical, material science, and biomedical applications. PMID:24400919

  7. A 3D-Printed High Power Nuclear Spin Polarizer

    PubMed Central

    Nikolaou, Panayiotis; Coffey, Aaron M.; Walkup, Laura L.; Gust, Brogan M.; LaPierre, Cristen D.; Koehnemann, Edward; Barlow, Michael J.; Rosen, Matthew S.; Goodson, Boyd M.; Chekmenev, Eduard Y.

    2015-01-01

    Three-dimensional printing with high-temperature plastic is used to enable spin exchange optical pumping (SEOP) and hyperpolarization of xenon-129 gas. The use of 3D printed structures increases the simplicity of integration of the following key components with a variable temperature SEOP probe: (i) in situ NMR circuit operating at 84 kHz (Larmor frequencies of 129Xe and 1H nuclear spins), (ii) <0.3 nm narrowed 200 W laser source, (iii) in situ high-resolution near-IR spectroscopy, (iv) thermoelectric temperature control, (v) retroreflection optics, and (vi) optomechanical alignment system. The rapid prototyping endowed by 3D printing dramatically reduces production time and expenses while allowing reproducibility and integration of “off-the-shelf” components and enables the concept of printing on demand. The utility of this SEOP setup is demonstrated here to obtain near-unity 129Xe polarization values in a 0.5 L optical pumping cell, including ~74 ± 7% at 1000 Torr xenon partial pressure, a record value at such high Xe density. Values for the 129Xe polarization exponential build-up rate [(3.63 ± 0.15) × 10?2 min?1] and in-cell 129Xe spin?lattice relaxation time (T1 = 2.19 ± 0.06 h) for 1000 Torr Xe were in excellent agreement with the ratio of the gas-phase polarizations for 129Xe and Rb (PRb ~ 96%). Hyperpolarization-enhanced 129Xe gas imaging was demonstrated with a spherical phantom following automated gas transfer from the polarizer. Taken together, these results support the development of a wide range of chemical, biochemical, material science, and biomedical applications. PMID:24400919

  8. Frequency selective detection of nuclear quadrupole resonance (NQR) spin echoes

    NASA Astrophysics Data System (ADS)

    Somasundaram, Samuel D.; Jakobsson, Andreas; Smith, John A. S.; Althoefer, Kaspar A.

    2006-05-01

    Nuclear Quadrupole Resonance (NQR) is a radio frequency (RF) technique that can be used to detect the presence of quadrupolar nuclei, such as the 14N nucleus prevalent in many explosives and narcotics. The technique has been hampered by low signal-to-noise ratios and is further aggravated by the presence of RF interference (RFI). To ensure accurate detection, proposed detectors should exploit the rich form of the NQR signal. Furthermore, the detectors should also be robust to any remaining residual interference, left after suitable RFI mitigation has been employed. In this paper, we propose a new NQR data model, particularly for the realistic case where multiple pulse sequences are used to generate trains of spin echoes. Furthermore, we refine two recently proposed approximative maximum likelihood (AML) detectors, enabling the algorithm to optimally exploit the data model of the entire echo train and also incorporate knowledge of the temperature dependent spin-echo decay time. The AML-based detectors ensure accurate detection and robustness against residual RFI, even when the temperature of the sample is not precisely known, by exploiting the dependencies of the NQR resonant lines on temperature. Further robustness against residual interference is gained as the proposed detector is frequency selective; exploiting only those regions of the spectrum where the NQR signal is expected. Extensive numerical evaluations based on both simulated and measured NQR data indicate that the proposed Frequency selective Echo Train AML (FETAML) detector offers a significant improvement as compared to other existing detectors.

  9. Single-Quantum Coherence Filter for Strongly Coupled Spin Systems for Localized 1H NMR Spectroscopy

    NASA Astrophysics Data System (ADS)

    Trabesinger, Andreas H.; Mueller, D. Christoph; Boesiger, Peter

    2000-08-01

    A pulse sequence for localized in vivo1H NMR spectroscopy is presented, which selectively filters single-quantum coherence built up by strongly coupled spin systems. Uncoupled and weakly coupled spin systems do not contribute to the signal output. Analytical calculations using a product operator description of the strongly coupled AB spin system as well as in vitro tests demonstrate that the proposed filter produces a signal output for a strongly coupled AB spin system, whereas the resonances of a weakly coupled AX spin system and of uncoupled spins are widely suppressed. As a potential application, the detection of the strongly coupled AA?BB? spin system of taurine at 1.5 T is discussed.

  10. Single Spin Asymmetries of Identified Hadrons in Polarized p+p at p

    E-print Network

    Single Spin Asymmetries of Identified Hadrons in Polarized p+p at p s = 62.4 and 200 GeV J.H. Lee hadrons, p #6; , K #6; , p, and â?¢ p, from transversely polarized proton collisions at p s = 200 and 62 into the fundamental mechanisms of transverse spin asymmetries and Quantum Chromodynamical description of hadronic

  11. All optical control of a single electron spin in diamond

    E-print Network

    Yiwen Chu; Matthew Markham; Daniel J. Twitchen; Mikhail D. Lukin

    2014-09-22

    Precise coherent control of the individual electronic spins associated with atom-like impurities in the solid state is essential for applications in quantum information processing and quantum metrology. We demonstrate all-optical initialization, fast coherent manipulation, and readout of the electronic spin of the negatively charged nitrogen-vacancy (NV$^-$) center in diamond at T$\\sim$7K. We then present the observation of a novel double-dark resonance in the spectroscopy of an individual NV center. These techniques open the door for new applications ranging from robust manipulation of spin states using geometric quantum gates to quantum sensing and information processing.

  12. Spin Responses in Nuclei and Nuclear Weak Processes in Stars

    NASA Astrophysics Data System (ADS)

    Suzuki, Toshio

    2015-04-01

    New shell-model Hamiltonians which can successfuly describe spin-dependent transition rates in nuclei are applied to study nuclear weak processes in stars. New v-induced reaction cross sections in 12C and 56Fe evaluated by the new Hamiltonians are shown to reproduce well the experimental data. Nucleosynthesis of light elements in supernova explosions (SNe) as well as v oscillation effects are discussed with the new cross sections. Electron capture and ?-decay rates in stellar environments are re-evaluated in fp- and sd-shell nuclei. Nucleosynthesis in Type-Ia SNe, rp-process and X-ray burst are discussed with the new reaction rates in Ni isotopes. Important roles of accurate e-capture and ?-decay rates in sd-shell nuclei on the cooling of stars with 8-10 solar masses by nuclear URCA processes and the fate of the stars are demonstrated. ?-decay half-lives of waiting-point nuclei at N =126 are evaluated by shell- model calculations, and r-process nucleosynthesis up to Th and U region in both core-collapse SNe and binary neutron star mergers are studied.

  13. Nuclear Spin-Dependent Parity Violation in Diatomic Molecules

    NASA Astrophysics Data System (ADS)

    Cahn, Sidney; Rahmlow, David; Steinecker, Matthew; Ammon, Jeffrey; Kirilov, Emil; Deveney, Edward; Paolino, Richard; Demille, David

    2010-03-01

    Nuclear spin-dependent parity nonconservation (NSD-PNC) effects arise from exchange of the Z^0 boson (parameterized by the electroweak coupling constants C2P,N) between electrons and the nucleus and from the interaction of electrons with the nuclear anapole moment, a parity-odd magnetic moment. The latter scales with the nucleon number A of the nucleus as A^23, while the Z^0 coupling is independent of A; the former will be the dominant source of NSD-PNC in nuclei with A >=20. The most precise result on NSD-PNC to date comes from a measurement of the hyperfine dependence of atomic PNC in ^133Cs, but this effect can be dramatically enhanced in diatomic molecules by bringing two levels of opposite parity close to degeneracy in a strong magnetic field. Level crossings have been observed in ^138BaF as a precursor to the test for parity violation in ^137BaF. We report on our measurements and planned design improvements to improve sensitivity in preparation for the parity violation experiment.

  14. Bell's inequality for a single spin 1/2 particle and quantum contextuality

    E-print Network

    Sayandeb Basu; Somshubhro Bandyopadhyay; Guruprasad Kar; Dipankar Home

    2001-03-18

    We argue that for a \\emph{single particle} Bell's inequality is a consequence of noncontextuality and is \\emph{incompatible} with statistical predictions of quantum mechanics. Thus noncontextual models can be empirically falsified, \\emph{independent} of locality condition. For this an appropriate entanglement between \\emph{disjoint} Hilbert spaces pertaining to translational and spin degrees of freedom of a single spin-1/2 particle is invoked

  15. Single Transverse Spin Asymmetry for Semi-Inclusive Deep Inelastic Scattering

    E-print Network

    Hisato Eguchi; Yuji Koike; Kazuhiro Tanaka

    2006-12-08

    Establishing the twist-3 formalsim for the single transverse spin asymmetry, we present a complete single-spin-dependent cross section for SIDIS, $ep^\\uparrow\\to e\\pi X$, associated with the twist-3 distribution for the transversely polarized nucleon. We emphasize that the consistency condition from the Ward identities for color gauge invariance is crucial to prove factorization property of the cross section.

  16. Influence of nuclear spin on chemical reactions: Magnetic isotope and magnetic field effects (A Review)

    PubMed Central

    Turro, Nicholas J.

    1983-01-01

    The course of chemical reactions involving radical pairs may depend on occurrence and orientation of nuclear spins in the pairs. The influence of nuclear spins is maximized when the radical pairs are confined to a space that serves as a cage that allows a certain degree of independent diffusional and rotational motion of the partners of the pair but that also encourages reencounters of the partners within a period which allows the nuclear spins to operate on the odd electron spins of the pair. Under the proper conditions, the nuclear spins can induce intersystem crossing between triplet and singlet states of radical pairs. It is shown that this dependence of intersystem crossing on nuclear spin leads to a magnetic isotope effect on the chemistry of radical pairs which provides a means of separating isotopes on the basis of nuclear spins rather than nuclear masses and also leads to a magnetic field effect on the chemistry of radical pairs which provides a means of influencing the course of polymerization by the application of weak magnetic fields. PMID:16593273

  17. Linear spin wave theory for single-Q incommensurate magnetic structures.

    PubMed

    Toth, S; Lake, B

    2015-04-29

    Linear spin wave theory provides the leading term in the calculation of the excitation spectra of long-range ordered magnetic systems as a function of 1/?S. This term is acquired using the Holstein-Primakoff approximation of the spin operator and valid for small ?S fluctuations of the ordered moment. We propose an algorithm that allows magnetic ground states with general moment directions and single-Q incommensurate ordering wave vector using a local coordinate transformation for every spin and a rotating coordinate transformation for the incommensurability. Finally we show, how our model can determine the spin wave spectrum of the magnetic C-site langasites with incommensurate order. PMID:25817594

  18. Boundary between the thermal and statistical polarization regimes in a nuclear spin ensemble

    SciTech Connect

    Herzog, B. E.; Cadeddu, D.; Xue, F.; Peddibhotla, P.; Poggio, M., E-mail: martino.poggio@unibas.ch [Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel (Switzerland)

    2014-07-28

    As the number of spins in an ensemble is reduced, the statistical fluctuations in its polarization eventually exceed the mean thermal polarization. This transition has now been surpassed in a number of recent nuclear magnetic resonance experiments, which achieve nanometer-scale detection volumes. Here, we measure nanometer-scale ensembles of nuclear spins in a KPF{sub 6} sample using magnetic resonance force microscopy. In particular, we investigate the transition between regimes dominated by thermal and statistical nuclear polarization. The ratio between the two types of polarization provides a measure of the number of spins in the detected ensemble.

  19. All spin-1 topological phases in a single spin-2 chain

    NASA Astrophysics Data System (ADS)

    Kshetrimayum, Augustine; Tu, Hong-Hao; Orús, Román

    2015-05-01

    Here we study the emergence of different symmetry-protected topological (SPT) phases in a spin-2 quantum chain. We consider a Heisenberg-like model with bilinear, biquadratic, bicubic, and biquartic nearest-neighbor interactions, as well as uniaxial anisotropy. We show that this model contains four different effective spin-1 SPT phases, corresponding to different representations of the (Z2×Z2)+T symmetry group, where Z2 is some ? rotation in the spin internal space and T is time reversal. One of these phases is equivalent to the usual spin-1 Haldane phase, while the other three are different but also typical of spin-1 systems. The model also exhibits an S O (5 ) -Haldane phase. Moreover, we also find that the transitions between the different effective spin-1 SPT phases are continuous and can be described by a c =2 conformal field theory. At such transitions, indirect evidence suggests a possible effective field theory of four massless Majorana fermions. The results are obtained by approximating the ground state of the system in the thermodynamic limit using matrix product states via the infinite time-evolving block decimation method, as well as by effective field theory considerations. Our findings show that different large effective spin-1 SPT phases separated by continuous quantum phase transitions can be stabilized in a simple quantum spin chain.

  20. Dynamic nuclear polarization of diamond. II. Nuclear orientation via electron spin-locking

    NASA Astrophysics Data System (ADS)

    Reynhardt, Eduard C.; High, Grant L.

    1998-09-01

    The polarization of 13C nuclei by means of nuclear orientation via electron spin-locking (Hartmann-Hahn cross-polarization between paramagnetic electrons and 13C nuclei) in a suite of natural diamonds has been investigated at 2.4 GHz and 9.6 GHz. The 13C polarization rate has been found to be independent of the microwave frequency, in agreement with theory. It is shown that since T1?(e)?T1(e) for diamond, the effective polarization rate of 13C nuclei is relatively low. At low paramagnetic impurities (Ce<5 ppm) 13C nuclei in diamond are polarized faster by employing continuous wave microwave radiation to drive the forbidden transitions of the 13C-electron spin system, the so-called solid effect.

  1. The Study of High Spin States in Nuclear Rotation by the Cranked Nilsson Strutinsky Model

    SciTech Connect

    Kardan, A.; Miri-Hakimabad, H.; Rafat-Motevalli, L. [Physics Department, Faculty of Science, Ferdowsi University of Mashhad, P. O. Box 91775-1436, Mashhad (Iran, Islamic Republic of)

    2010-11-24

    A heavy-ion reaction can populate nuclear states of very high angular momentum with values of the order of I = 60 achievable. The reaction produces such configurations with a considerable internal excitation, but the emission of a few neutrons reduces the excitation energy effectively while not decreasing the spin by much. At sufficiently high spin the pairing is destroyed completely and the rigid-body moment of inertia becomes a good approximation. Even in this regime, however, the single-particle structure remains important and shell effects can be studied in terms of a rotating phenomenological shell model. On the theoretical side the cranked Nilsson strutinsky model has proved to be a successful tool to describe rapidly rotating nucleus. Indeed, this model gives a microscopic description of the influence of rotation on single-particle motion. This paper will concentrate on introduction to the cranked Nilsson strutinsky model in details. First, we explain the cranking model and the rotating liquid-drop model, then introduce the shell correction method. Also, we describe terminating bands, which show a continuous transition from high collectivity to a pure particle-hole state.

  2. Single spin channels in Fe-doped CoTiSb semiconductor

    NASA Astrophysics Data System (ADS)

    Wang, L. Y.; Dai, X. F.; Wang, X. T.; Li, P. P.; Xia, Q. L.; Zhang, Y.; Cui, Y. T.; Liu, G. D.

    2015-07-01

    The Fe-based single atomic chains are designed in the semiconductive CoTiSb matrix by continuously substituting Fe for Ti, Ti-Sb or Co in [0 0 1] crystallographic direction. The electronic structures and magnetic properties of CoTiSb supercells with the Fe-based single atomic chains have been investigated using the first-principles calculations. We predict that the single atomic chains of Fe-Sb (achieved by substituting Fe for Ti) and Fe-vacancy (achieved by substituting Fe for Co) show a 100% spin polarization and form a very small single spin channel. The single atomic chains of Fe-Fe (achieved by substituting Fe for Ti and Sb) show a spin-gapless characteristic.

  3. Conditional control of donor nuclear spins in silicon using stark shifts.

    PubMed

    Wolfowicz, Gary; Urdampilleta, Matias; Thewalt, Mike L W; Riemann, Helge; Abrosimov, Nikolai V; Becker, Peter; Pohl, Hans-Joachim; Morton, John J L

    2014-10-10

    Electric fields can be used to tune donor spins in silicon using the Stark shift, whereby the donor electron wave function is displaced by an electric field, modifying the hyperfine coupling between the electron spin and the donor nuclear spin. We present a technique based on dynamic decoupling of the electron spin to accurately determine the Stark shift, and illustrate this using antimony donors in isotopically purified silicon-28. We then demonstrate two different methods to use a dc electric field combined with an applied resonant radio-frequency (rf) field to conditionally control donor nuclear spins. The first method combines an electric-field induced conditional phase gate with standard rf pulses, and the second one simply detunes the spins off resonance. Finally, we consider different strategies to reduce the effect of electric field inhomogeneities and obtain above 90% process fidelities. PMID:25375741

  4. Conditional Control of Donor Nuclear Spins in Silicon Using Stark Shifts

    NASA Astrophysics Data System (ADS)

    Wolfowicz, Gary; Urdampilleta, Matias; Thewalt, Mike L. W.; Riemann, Helge; Abrosimov, Nikolai V.; Becker, Peter; Pohl, Hans-Joachim; Morton, John J. L.

    2014-10-01

    Electric fields can be used to tune donor spins in silicon using the Stark shift, whereby the donor electron wave function is displaced by an electric field, modifying the hyperfine coupling between the electron spin and the donor nuclear spin. We present a technique based on dynamic decoupling of the electron spin to accurately determine the Stark shift, and illustrate this using antimony donors in isotopically purified silicon-28. We then demonstrate two different methods to use a dc electric field combined with an applied resonant radio-frequency (rf) field to conditionally control donor nuclear spins. The first method combines an electric-field induced conditional phase gate with standard rf pulses, and the second one simply detunes the spins off resonance. Finally, we consider different strategies to reduce the effect of electric field inhomogeneities and obtain above 90% process fidelities.

  5. A high-performance Fortran code to calculate spin- and parity-dependent nuclear level densities

    NASA Astrophysics Data System (ADS)

    Sen'kov, R. A.; Horoi, M.; Zelevinsky, V. G.

    2013-01-01

    A high-performance Fortran code is developed to calculate the spin- and parity-dependent shell model nuclear level densities. The algorithm is based on the extension of methods of statistical spectroscopy and implies exact calculation of the first and second Hamiltonian moments for different configurations at fixed spin and parity. The proton-neutron formalism is used. We have applied the method for calculating the level densities for a set of nuclei in the sd-, pf-, and pf+g- model spaces. Examples of the calculations for 28Si (in the sd-model space) and 64Ge (in the pf+g-model space) are presented. To illustrate the power of the method we estimate the ground state energy of 64Ge in the larger model space pf+g, which is not accessible to direct shell model diagonalization due to the prohibitively large dimension, by comparing with the nuclear level densities at low excitation energy calculated in the smaller model space pf. Program summaryProgram title: MM Catalogue identifier: AENM_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AENM_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 193181 No. of bytes in distributed program, including test data, etc.: 1298585 Distribution format: tar.gz Programming language: Fortran 90, MPI. Computer: Any architecture with a Fortran 90 compiler and MPI. Operating system: Linux. RAM: Proportional to the system size, in our examples, up to 75Mb Classification: 17.15. External routines: MPICH2 (http://www.mcs.anl.gov/research/projects/mpich2/) Nature of problem: Calculating of the spin- and parity-dependent nuclear level density. Solution method: The algorithm implies exact calculation of the first and second Hamiltonian moments for different configurations at fixed spin and parity. The code is parallelized using the Message Passing Interface and a master-slaves dynamical load-balancing approach. Restrictions: The program uses two-body interaction in a restricted single-level basis. For example, GXPF1A in the pf-valence space. Running time: Depends on the system size and the number of processors used (from 1 min to several hours).

  6. Cryogenic sample exchange NMR probe for magic angle spinning dynamic nuclear polarization

    E-print Network

    Barnes, Alexander

    We describe a cryogenic sample exchange system that dramatically improves the efficiency of magic angle spinning (MAS) dynamic nuclear polarization (DNP) experiments by reducing the time required to change samples and by ...

  7. Atomic-Scale Nuclear Spin Imaging Using Quantum-Assisted Sensors in Diamond

    E-print Network

    Bissbort, U.

    Nuclear spin imaging at the atomic level is essential for the understanding of fundamental biological phenomena and for applications such as drug discovery. The advent of novel nanoscale sensors promises to achieve the ...

  8. Nuclear spin-lattice relaxation via paramagnetic centers in solids. 13C NMR of diamonds

    NASA Astrophysics Data System (ADS)

    Mark Henrichs, P.; Cofield, Milton L.; Young, Ralph H.; Michael Hewitt, J.

    Diamonds of gem quality give narrow 13C NMR signals (about 200 Hz width at half height) even in a spectrometer designed for use with liquids. Industrial diamond powders require magic-angle spinning to give narrow NMR resonances. Spin-lattice relaxation in the industrial powders depends on time ( t) exponentially in t {1}/{2}. A theory is developed to explain this behavior in terms of relaxation by paramagnetic centers in the absence of nuclear spin diffusion.

  9. Spin-Orbit Coupling in the Pseudoscalar Meson Theory of Nuclear Forces

    Microsoft Academic Search

    Gentaro Araki

    1955-01-01

    The fourth order nuclear forces were derived by Sato on the basis of the pseudoscalar meson theory. The spin-orbit coupling contained in his result is examined in the approximate way. The doublet interval ^2D1\\/2-^2D5\\/2 of the 17O nucleus due to this spin-orbit coupling is calculated taking into account all spin-orbit couplings between seventeen nucleons according to the method of Talmi.

  10. Local Spin Anisotropy Effects upon the Magnetization of Dimer Single Molecule Magnets

    NASA Astrophysics Data System (ADS)

    Klemm, Richard A.; Efremov, Dmitri V.

    2006-09-01

    We present an exactly soluble model of equal spin s1 dimer single molecule magnets. The dimer spins interact via the Heisenberg, Zeeman, and the most general quadratic local and global anisotropic exchange interactions. We derive the Hamiltonian matrix for the general case with each type of anisotropy. For antiferromagnetic couplings and s1 > 1/2, the low temperature T magnetization exhibits a strong influence of single-ion anisotropy. Our results suggest a substantial presence of axial single-ion anisotropy in the s1 = 5/2 Fe2 dimer, [Fe(salen)Cl]2.

  11. High Field Dynamic Nuclear Polarization with High-Spin Transition Metal Ions

    E-print Network

    Barnes, Alexander

    We report the dynamic nuclear polarization of 1H spins in magic-angle-spinning spectra recorded at 5 T and 84 K via the solid effect using Mn2+ and Gd[superscript 3+] complexes as polarizing agents. We show that the magnitude ...

  12. Macroscopic nuclear spin diffusion constants of rotating polycrystalline solids from first-principles simulation

    NASA Astrophysics Data System (ADS)

    Halse, Meghan E.; Zagdoun, Alexandre; Dumez, Jean-Nicolas; Emsley, Lyndon

    2015-05-01

    A method for quantitatively calculating nuclear spin diffusion constants directly from crystal structures is introduced. This approach uses the first-principles low-order correlations in Liouville space (LCL) method to simulate spin diffusion in a box, starting from atomic geometry and including both magic-angle spinning (MAS) and powder averaging. The LCL simulations are fit to the 3D diffusion equation to extract quantitative nuclear spin diffusion constants. We demonstrate this method for the case of 1H spin diffusion in ice and L-histidine, obtaining diffusion constants that are consistent with literature values for 1H spin diffusion in polymers and that follow the expected trends with respect to magic-angle spinning rate and the density of nuclear spins. In addition, we show that this method can be used to model 13C spin diffusion in diamond and therefore has the potential to provide insight into applications such as the transport of polarization in non-protonated systems.

  13. Final-State Interactions and Single-Spin Asymmetries in Semi-Inclusive Deep Inelastic Scattering

    SciTech Connect

    Brodsky, Stanley J.

    2002-01-31

    Recent measurements from the HERMES and SMC collaborations show a remarkably large azimuthal single-spin asymmetries AUL and AUT of the proton in semi-inclusive pion leptoproduction {gamma}*(q)p {yields} {pi}X. We show that final-state interactions from gluon exchange between the outgoing quark and the target spectator system lead to single-spin asymmetries in deep inelastic lepton-proton scattering at leading twist in perturbative QCD; i.e., the rescattering corrections are not power-law suppressed at large photon virtuality Q{sup 2} at fixed x{sub bj}. The existence of such single-spin asymmetries requires a phase difference between two amplitudes coupling the proton target with J{sub P}{sup z} = {+-} 1/2 to the same final-state, the same amplitudes which are necessary to produce a nonzero proton anomalous magnetic moment. We show that the exchange of gauge particles between the outgoing quark and the proton spectators produces a Coulomb-like complex phase which depends on the angular momentum L{sup z} of the proton's constituents and is thus distinct for different proton spin amplitudes. The single-spin asymmetry which arises from such final-state interactions does not factorize into a product of distribution function and fragmentation function, and it is not related to the transversity distribution {delta}q(x, Q) which correlates transversely polarized quarks with the spin of the transversely polarized target nucleon.

  14. Final-State Interactions and Single-Spin Asymmetries in Semi-inclusive Deep Inelastic Scattering

    SciTech Connect

    Brodsky, Stanley J.; /SLAC; Hwang, Dae Sung; /SLAC /Sejong U.; Schmidt, Ivan; /Santa Maria U., Valparaiso

    2007-11-14

    Recent measurements from the HERMES and SMC collaborations show a remarkably large azimuthal single-spin asymmetries A{sub UL} and A{sub UT} of the proton in semi-inclusive pion leptoproduction {gamma}*(q)p {yields} {pi}X. We show that final-state interactions from gluon exchange between the outgoing quark and the target spectator system leads to single-spin asymmetries in deep inelastic lepton-proton scattering at leading twist in perturbative QCD; i.e., the rescattering corrections are not power-law suppressed at large photon virtuality q{sup 2} at fixed x{sub bj}. The existence of such single-spin asymmetries requires a phase difference between two amplitudes coupling the proton target with J{sup z}{sub p} = {+-}1/2 to the same final-state, the same amplitudes which are necessary to produce a nonzero proton anomalous magnetic moment. We show that the exchange of gauge particles between the outgoing quark and the proton spectators produces a Coulomb-like complex phase which depends on the angular momentum L{sup z} of the proton's constituents and thus is distinct for different proton spin amplitudes. The single-spin asymmetry which arises from such final-state interactions does not factorize into a product of structure function and fragmentation function, and it is not related to the transversity distribution {delta}q(x;Q) which correlates transversely polarized quarks with the spin of the transversely polarized target nucleon.

  15. Nuclear Spin Gyroscope Based on an Atomic Comagnetometer T. W. Kornack, R. K. Ghosh, and M. V. Romalis

    E-print Network

    Romalis, Mike

    Nuclear Spin Gyroscope Based on an Atomic Comagnetometer T. W. Kornack, R. K. Ghosh, and M. V; published 29 November 2005) We describe a nuclear spin gyroscope based on an alkali their gyroscopic precession. Spin precession due to magnetic fields as well as their gradients and transients can

  16. Optimal control of fast and high-fidelity quantum gates with electron and nuclear spins of a nitrogen-vacancy center in diamond

    NASA Astrophysics Data System (ADS)

    Chou, Yi; Huang, Shang-Yu; Goan, Hsi-Sheng

    2015-05-01

    A negatively charged nitrogen-vacancy (NV) center in diamond has been recognized as a good solid-state qubit. A system consisting of the electronic spin of the NV center and hyperfine-coupled nitrogen and additionally nearby carbon nuclear spins can form a quantum register of several qubits for quantum information processing or as a node in a quantum repeater. Several impressive experiments on the hybrid electron and nuclear spin register have been reported, but fidelities achieved so far are not yet at or below the thresholds required for fault-tolerant quantum computation (FTQC). Using quantum optimal control theory based on the Krotov method, we show here that fast and high-fidelity single-qubit and two-qubit gates in the universal quantum gate set for FTQC, taking into account the effects of the leakage state, nearby noise qubits, and distant bath spins, can be achieved with errors less than those required by the threshold theorem of FTQC.

  17. Recent Results of Target Single-Spin Asymmetry Experiments at Jefferson Lab

    SciTech Connect

    Jiang, Xiaodong [Los Alamos National Lab

    2013-08-01

    We report recent results from Jefferson Lab Hall A “Neutron Transversity” experiment (E06-010). Transversely polarized target single-spin asymmetry AUT and beam-target double-spin asymmetry A{sub LT} have been measured in semi-inclusive deep-inelastic scattering (SIDIS) reactions on a polarized neutron ({sup 3}He) target. Collins-type and Sivers-type asymmetries have been extracted from A{sub UT} for charged pion SIDIS productions, which are sensitive to quark transversity and Sivers distributions, correspondingly. Double spin asymmetry A{sub LT} is sensitive to a specific quark transverse momentum dependent parton distribution (TMD), the so-called “ transverse helicity” (g{sub 1T} ) distributions. In addition, target single-spin asymmetries A{sub y} in inclusive electron scattering on a transversely polarized {sup 3}He target in quasi-elastic and deep inelastic kinematics were also measured in Hall A.

  18. Quantum Stirling heat engine and refrigerator with single and coupled spin systems

    NASA Astrophysics Data System (ADS)

    Huang, Xiao-Li; Niu, Xin-Ya; Xiu, Xiao-Ming; Yi, Xue-Xi

    2014-02-01

    We study the reversible quantum Stirling cycle with a single spin or two coupled spins as the working substance. With the single spin as the working substance, we find that under certain conditions the reversed cycle of a heat engine is NOT a refrigerator, this feature holds true for a Stirling heat engine with an ion trapped in a shallow potential as its working substance. The efficiency of quantum Stirling heat engine can be higher than the efficiency of the Carnot engine, but the performance coefficient of the quantum Stirling refrigerator is always lower than its classical counterpart. With two coupled spins as the working substance, we find that a heat engine can turn to a refrigerator due to the increasing of the coupling constant, this can be explained by the properties of the isothermal line in the magnetic field-entropy plane.

  19. Spin reorientation transition process in single crystal NdFeO3

    NASA Astrophysics Data System (ADS)

    Song, Gaibei; Jiang, Junjie; Kang, Baojuan; Zhang, Jincang; Cheng, Zhenxiang; Ma, Guohong; Cao, Shixun

    2015-06-01

    The spin reorientation transition in single crystal NdFeO3 is studied using AC magnetic susceptibility, hysteresis loops, and polarized terahertz (THz) time domain spectroscopy measurements. Different frequency dependence behaviors of AC susceptibility reflect that the dynamic response of magnetization inside the spin reorientation region differs from the phase outside the transition region. The magnetization hysteresis loops at different temperatures reveal that domains formed during the spin reorientation process, which coincides with the abrupt increase of AC magnetic susceptibility during the transition. In addition, temperature dependent THz wave excitation of quasi-antiferromagnetic mode indicates the process of spin reorientation as a continuous rotation of Fe3+ spins rather than a mixed phase of ?4 and ?2.

  20. Excited-state spectroscopy using single-spin manipulation in diamond

    E-print Network

    G. D. Fuchs; V. V. Dobrovitski; R. Hanson; A. Batra; C. D. Weis; T. Schenkel; D. D. Awschalom

    2008-06-11

    We use single-spin resonant spectroscopy to study the spin structure in the orbital excited-state of a diamond nitrogen-vacancy center at room temperature. We find that the excited state spin levels have a zero-field splitting that is approximately half of the value of the ground state levels, a g-factor similar to the ground state value, and a hyperfine splitting ~20x larger than in the ground state. In addition, the width of the resonances reflects the electronic lifetime in the excited state. We also show that the spin-splitting can significantly differ between NV centers, likely due to the effects of local strain, which provides a pathway to control over the spin Hamiltonian and may be useful for quantum information processing.

  1. Single-shot readout of spin qubits in Si/SiGe quantum dots

    NASA Astrophysics Data System (ADS)

    Simmons, Christie

    2012-02-01

    Si/SiGe quantum dots are an attractive option for spin qubit development, because of the long coherence times for electron spins in silicon, arising from weak hyperfine interaction and low spin orbit coupling. I will present measurements of gate-defined single and double quantum dots formed in Si/SiGe semiconductor heterostuctures. Control of the gate voltages on these dots enables tuning of the tunnel coupling to the leads and to other dots. Careful tuning of these tunnel rates, in combination with fast, pulsed-gate manipulation and spin-to-charge conversion, allow spin state measurement using an integrated quantum point contact as a local charge detector. Single spin qubit readout relies on the Zeeman energy splitting from an external magnetic field for spin-to-charge conversion. Two-electron singlet-triplet qubits, on the other hand, can be measured by using Pauli spin blockade of tunneling between the dots to readout the qubit even at zero magnetic field. I will present real-time, single-shot readout measurements of both individual spin [1] and singlet-triplet qubits [2] in gated Si/SiGe quantum dots. Work performed in collaboration with J. R. Prance, Zhan Shi, B. J. Van Bael, Teck Seng Koh, D. E. Savage, M. G. Lagally, R. Joynt, L. R. Schreiber, L. M. K. Vandersypen, M. Friesen, S. N. Coppersmith, and M. A. Eriksson. [4pt] [1] C. B. Simmons et al. Physical Review Letters 106, 156804 (2011). [0pt] [2] J. R. Prance, et al., e-print: http://lanl.arxiv.org/abs/1110.6431

  2. Testing the validity of the single-spin approximation in inspiral-merger-ringdown waveforms

    E-print Network

    Michael Pürrer; Mark Hannam; P. Ajith; Sascha Husa

    2013-06-10

    Gravitational-wave signals from black-hole binaries with non-precessing spins are described by four parameters -- each black hole's mass and spin. It has been shown that the dominant spin effects can be modeled by a \\emph{single} spin parameter, leading to the development of several \\emph{three-parameter} waveform models. Previous studies indicate that these models should be adequate for gravitational-wave detection. In this paper we focus on the systematic biases that would result from using them to estimate binary parameters, and consider a one-parameter family of configurations at one choice of mass ratio and effective single spin. We find that for low-mass binaries within that family of configurations, where the observable waveform is dominated by the inspiral, the systematic bias in all physical parameters is smaller than the parameter uncertainty due to degeneracies between the mass ratio and the spins, at least up to signal-to-noise ratios (SNRs) of 50. For higher-mass binaries, where the merger and ringdown make a greater contribution to the observed signal, the bias in the mass ratio is comparable to its uncertainty at SNRs of only $\\sim$30, and the bias in the measurement of the total spin is \\emph{larger} than the uncertainty defined by the 90% confidence region even at an SNR of only 10. Although this bias may be mitigated in future models by a better choice of single-effective-spin parameter, these results suggest that it may be possible to accurately measure \\emph{both} black-hole spins in intermediate-mass binaries.

  3. Measurements of Kondo and Spin Splitting in Single-Electron Transistors

    Microsoft Academic Search

    A. Kogan; S. Amasha; D. Goldhaber-Gordon; G. Granger; M. A. Kastner; Hadas Shtrikman

    2004-01-01

    We measure the spin splitting in a magnetic field B of localized states in single-electron transistors using a new method, inelastic spin-flip cotunneling. Because it involves only internal excitations, this technique gives the most precise value of the Zeeman energy Delta=|g|muBB. In the same devices we also measure the splitting with B of the Kondo peak in differential conductance. The

  4. Evidence for a Single-Spin Azimuthal Asymmetry in Semi-inclusive Pion Electroproduction

    Microsoft Academic Search

    A. Airapetian; N. Akopov; M. Amarian; E. C. Aschenauer; H. Avakian; R. Avakian; A. Avetissian; E. Avetissian; B. Bains; C. Baumgarten; M. Beckmann; S. Belostotski; J. E. Belz; Th. Benisch; S. Bernreuther; N. Bianchi; J. Blouw; H. Böttcher; A. Borissov; M. Bouwhuis; J. Brack; S. Brauksiepe; B. Braun; B. Bray; St. Brons; W. Brückner; A. Brüll; E. E. Bruins; H. J. Bulten; G. P. Capitani; P. Carter; P. Chumney; E. Cisbani; G. R. Court; P. F. Dalpiaz; E. de Sanctis; D. de Schepper; E. Devitsin; P. K. de Witt Huberts; P. di Nezza; M. Düren; A. Dvoredsky; G. Elbakian; J. Ely; A. Fantoni; A. Fechtchenko; M. Ferstl; K. Fiedler; B. W. Filippone; H. Fischer; B. Fox; J. Franz; S. Frullani; M.-A. Funk; Y. Gärber; H. Gao; F. Garibaldi; G. Gavrilov; P. Geiger; V. Gharibyan; A. Golendukhin; G. Graw; O. Grebeniouk; P. W. Green; L. G. Greeniaus; C. Grosshauser; M. Guidal; A. Gute; V. Gyurjyan; J. P. Haas; W. Haeberli; J.-O. Hansen; M. Hartig; D. Hasch; O. Häusser; F. H. Heinsius; R. Henderson; M. Henoch; R. Hertenberger; Y. Holler; R. J. Holt; W. Hoprich; H. Ihssen; M. Iodice; A. Izotov; H. E. Jackson; A. Jgoun; R. Kaiser; E. Kinney; A. Kisselev; P. Kitching; H. Kobayashi; N. Koch; K. Königsmann; M. Kolstein; H. Kolster; V. Korotkov; W. Korsch; V. Kozlov; L. H. Kramer; V. G. Krivokhijine; M. Kurisuno; G. Kyle; W. Lachnit; P. Lenisa; W. Lorenzon; N. C. Makins; F. K. Martens; J. W. Martin; F. Masoli; A. Mateos; M. McAndrew; K. McIlhany; R. D. McKeown; F. Meissner; F. Menden; A. Metz; N. Meyners; O. Mikloukho; C. A. Miller; M. A. Miller; R. Milner; A. Most; V. Muccifora; R. Mussa; A. Nagaitsev; Y. Naryshkin; A. M. Nathan; F. Neunreither; M. Niczyporuk; W.-D. Nowak; M. Nupieri; K. A. Oganessyan; T. G. O'Neill; R. Openshaw; J. Ouyang; B. R. Owen; V. Papavassiliou; S. F. Pate; M. Pitt; S. Potashov; D. H. Potterveld; G. Rakness; A. Reali; R. Redwine; A. R. Reolon; R. Ristinen; K. Rith; P. Rossi; S. Rudnitsky; M. Ruh; D. Ryckbosch; Y. Sakemi; I. Savin; C. Scarlett; A. Schäfer; F. Schmidt; H. Schmitt; G. Schnell; K. P. Schüler; A. Schwind; J. Seibert; T.-A. Shibata; K. Shibatani; T. Shin; V. Shutov; C. Simani; A. Simon; K. Sinram; P. Slavich; M. Spengos; E. Steffens; J. Stenger; J. Stewart; U. Stoesslein; M. Sutter; H. Tallini; S. Taroian; A. Terkulov; O. Teryaev; E. Thomas; B. Tipton; M. Tytgat; G. M. Urciuoli; J. F. van den Brand; G. van der Steenhoven; R. van de Vyver; J. J. van Hunen; M. C. Vetterli; V. Vikhrov; M. G. Vincter; J. Visser; E. Volk; W. Wander; J. Wendland; S. E. Williamson; T. Wise; K. Woller; S. Yoneyama; H. Zohrabian

    2000-01-01

    Single-spin asymmetries for semi-inclusive pion production in deep-inelastic scattering have been measured for the first time. A significant target-spin asymmetry of the distribution in the azimuthal angle phi of the pion relative to the lepton scattering plane was formed for pi+ electroproduction on a longitudinally polarized hydrogen target. The corresponding analyzing power in the sinphi moment of the cross section

  5. Mechanisms for Electric Field Control of Single Spin Relaxation in Double Quantum Dots

    NASA Astrophysics Data System (ADS)

    Srinivasa, V.; Nowack, K. C.; Shafiei, M.; Vandersypen, L. M. K.; Taylor, J. M.

    2013-03-01

    We theoretically investigate electrically-tunable spin-flip transitions for a single electron confined within a double quantum dot. In the presence of spin-orbit and hyperfine interactions, the rate at which phonon-induced spin relaxation occurs depends non-monotonically on the detuning between the dots. We analyze this detuning dependence for both direct decay to the ground state and indirect decay via an intermediate excited state of the double dot. A description in terms of a simple toy model captures characteristic features of the relaxation rate recently measured for GaAs double quantum dots. Our results suggest that spin-orbit mediated relaxation via phonons serves as the dominant mechanism through which the electron spin-flip rate in these systems varies with detuning. We theoretically investigate electrically-tunable spin-flip transitions for a single electron confined within a double quantum dot. In the presence of spin-orbit and hyperfine interactions, the rate at which phonon-induced spin relaxation occurs depends non-monotonically on the detuning between the dots. We analyze this detuning dependence for both direct decay to the ground state and indirect decay via an intermediate excited state of the double dot. A description in terms of a simple toy model captures characteristic features of the relaxation rate recently measured for GaAs double quantum dots. Our results suggest that spin-orbit mediated relaxation via phonons serves as the dominant mechanism through which the electron spin-flip rate in these systems varies with detuning. Support from DARPA MTO and IARPA is gratefully acknowledged.

  6. The classical nature of nuclear spin noise near clock transitions of Bi donors in silicon

    E-print Network

    Wen-Long Ma; Gary Wolfowicz; Shu-Shen Li; John J. L. Morton; Ren-Bao Liu

    2015-05-07

    Whether a quantum bath can be approximated as classical noise is a fundamental issue in central spin decoherence and also of practical importance in designing noise-resilient quantum control. Spin qubits based on bismuth donors in silicon have tunable interactions with nuclear spin baths and are first-order insensitive to magnetic noise at so-called clock-transitions (CTs). This system is therefore ideal for studying the quantum/classical nature of nuclear spin baths since the qubit-bath interaction strength determines the back-action on the baths and hence the adequacy of a classical noise model. We develop a Gaussian noise model with noise correlations determined by quantum calculations and compare the classical noise approximation to the full quantum bath theory. We experimentally test our model through dynamical decoupling sequence of up to 128 pulses, finding good agreement with simulations and measuring electron spin coherence times approaching one second - notably using natural silicon. Our theoretical and experimental study demonstrates that the noise from a nuclear spin bath is analogous to classical Gaussian noise if the back-action of the qubit on the bath is small compared to the internal bath dynamics, as is the case close to CTs. However, far from the CTs, the back-action of the central spin on the bath is such that the quantum model is required to accurately model spin decoherence.

  7. Measurement of the electron spin relaxation time in a silicon quantum dot using single-shot readout

    NASA Astrophysics Data System (ADS)

    Prance, J. R.; Simmons, C. B.; van Bael, B. J.; Seng Koh, Teck; Shi, Zhan; Savage, D. E.; Lagally, M. G.; Joynt, R.; Friesen, Mark; Coppersmith, S. N.; Eriksson, M. A.

    2011-03-01

    Electron spins in Si/SiGe quantum dots are promising candidates as qubits for quantum information processing, because spins in silicon couple weakly to the host material. We present a measurement of the spin lifetime for electrons in a silicon quantum dot. The spin state of individual electrons is measured using single-shot charge readout and spin-to-charge conversion: only spin-up electrons will tunnel off the quantum dot. Charge sensing is performed with an integrated quantum point contact that detects single electron tunnel events as steps in current. We determine the relaxation time by measuring the fraction of measurements that contain spin-up tunneling events as a function of the time that the electron spins are held on the quantum dot. We observe a clear decay in this spin-up fraction versus time, and an exponential fit yields T1 ~ 2.8 seconds at a magnetic field of 1.85 T .

  8. Reversible Single Spin Control of Individual Magnetic Molecule by Hydrogen Atom Adsorption

    PubMed Central

    Liu, Liwei; Yang, Kai; Jiang, Yuhang; Song, Boqun; Xiao, Wende; Li, Linfei; Zhou, Haitao; Wang, Yeliang; Du, Shixuan; Ouyang, Min; Hofer, Werner A.; Castro Neto, Antonio H.; Gao, Hong-Jun

    2013-01-01

    The reversible control of a single spin of an atom or a molecule is of great interest in Kondo physics and a potential application in spin based electronics. Here we demonstrate that the Kondo resonance of manganese phthalocyanine molecules on a Au(111) substrate have been reversibly switched off and on via a robust route through attachment and detachment of single hydrogen atom to the magnetic core of the molecule. As further revealed by density functional theory calculations, even though the total number of electrons of the Mn ion remains almost the same in the process, gaining one single hydrogen atom leads to redistribution of charges within 3d orbitals with a reduction of the molecular spin state from S = 3/2 to S = 1 that directly contributes to the Kondo resonance disappearance. This process is reversed by a local voltage pulse or thermal annealing to desorb the hydrogen atom. PMID:23383378

  9. Gauge invariance of the nuclear spin/electron orbit interaction and NMR spectral parameters.

    PubMed

    Lazzeretti, Paolo

    2012-08-21

    A gauge transformation of the vector potential A(m(I)), associated to the magnetic dipole m(I) of nucleus I in a molecule, has been studied. The conditions for gauge invariance of nuclear magnetic shielding, nuclear spin/electron orbit contribution to spin-spin coupling between two nuclei, I and J, and electronic current density induced by m(I), have been expressed via quantum mechanical sum rules that are identically satisfied for exact and optimal variational wavefunctions. It is shown that separate diamagnetic and paramagnetic contributions to the properties transform into one another in the gauge transformation, whereas their sum is invariant. Therefore, only total response properties have a physical meaning. In particular, the disjoint diamagnetic and paramagnetic components of nuclear spin/electron orbit contributions to coupling constants are not uniquely defined. The diamagnetic contribution to the nuclear spin-spin coupling tensor, evaluated as an expectation value in the Ramsey theory, can alternatively be expressed as a sum-over-states formula, by rewriting the second-order Hamiltonian in commutator form à la Geertsen, as previously reported by Sauer. Other sum-over-states formulae are obtained via a gauge transformation, by a procedure formally allowing for a continuous translation of the origin of the m(I)-induced current density, analogous to those previously proposed for magnetizabilities and nuclear magnetic shielding. PMID:22920104

  10. Spin-asymmetry energy of nuclear matter Physik-Department T39, Technische Universitt Mnchen, D-85747 Garching, Germany

    E-print Network

    Weise, Wolfram

    Spin-asymmetry energy of nuclear matter N. Kaiser Physik-Department T39, Technische Universität the density-dependent spin-asymmetry energy S kf of isospin-symmetric nuclear matter in the three of freedom in the description of the nuclear many- body dynamics. The contributions to the energy per

  11. Dynamic strain-mediated coupling of a single diamond spin to a mechanical resonator.

    PubMed

    Ovartchaiyapong, Preeti; Lee, Kenneth W; Myers, Bryan A; Jayich, Ania C Bleszynski

    2014-01-01

    The development of hybrid quantum systems is central to the advancement of emerging quantum technologies, including quantum information science and quantum-assisted sensing. The recent demonstration of high-quality single-crystal diamond resonators has led to significant interest in a hybrid system consisting of nitrogen-vacancy centre spins that interact with the resonant phonon modes of a macroscopic mechanical resonator through crystal strain. However, the nitrogen-vacancy spin-strain interaction has not been well characterized. Here, we demonstrate dynamic, strain-mediated coupling of the mechanical motion of a diamond cantilever to the spin of an embedded nitrogen-vacancy centre. Via quantum control of the spin, we quantitatively characterize the axial and transverse strain sensitivities of the nitrogen-vacancy ground-state spin. The nitrogen-vacancy centre is an atomic scale sensor and we demonstrate spin-based strain imaging with a strain sensitivity of 3 × 10(-6) strain Hz(-1/2). Finally, we show how this spin-resonator system could enable coherent spin-phonon interactions in the quantum regime. PMID:25034828

  12. Testing for parity violation in nuclei using spin density matrices for nuclear density functionals

    NASA Astrophysics Data System (ADS)

    Barrett, B. R.; Giraud, B. G.

    2015-06-01

    The spin density matrix (SDM) used in atomic and molecular physics is revisited for nuclear physics, in the context of the radial density functional theory. The vector part of the SDM defines a ‘hedgehog’ situation, which exists only if nuclear states contain some amount of parity violation. A toy model is given as an illustrative example.

  13. Spin transfer and current-induced switching in a ferromagnetic single-electron transistor

    NASA Astrophysics Data System (ADS)

    Jalil, M. B. A.; Tan, S. G.

    2005-12-01

    We propose a theoretical model of current-induced magnetization (CIMS) switching in a ferromagnetic single electron tunneling (FM-SET) transistor. The CIMS effect arises from the transfer of spin angular momentum from the net spin accumulation ?S on the island electrode to the local magnetic moments via s-d exchange coupling. Based on the single-domain model, we derive an analytical expression for the critical spin accumulation ?Ssw on the island for CIMS, and calculate the M-?S hysteresis curves which represent the effect of ?S on the island moments. This magnetization response is then related to the charge and spin transport model in the SET transistor. We extend the Korotkov scheme spin-dependent “orthodox” theory of single charge tunneling, by linking the transport I-V and ?S-V characteristics to the M-?S hysteresis. We thus determine ?S as a function of external bias or current and hence obtain the switching current density jsw for CIMS. For a typical spin polarization P=60% of the source electrode, jsw is calculated to be of the order of 105A/cm2 , and this falls to just ˜3×104A/cm2 when a near half-metal (P=90%) is used. This value is several orders of magnitude smaller than jsw observed in multilayer and magnetic tunnel junction structures. The SET transistor is an ideal device for the CIMS effect since (i) a small amount of moments (on the island) need to be switched to generate a large change in conduction and (ii) the island electrode being isolated from the rest of the circuit by spin-dependent tunnel barriers effectively confines the spin accumulation ?S in the vicinity of these moments.

  14. Soft-Fermion-Pole Mechanism to Single Spin Asymmetry in Hadronic Pion Production

    SciTech Connect

    Koike, Yuji; Tomita, Tetsuya [Department of Physics, Niigata University, Ikarashi, Niigata 950-2181 (Japan)

    2009-08-04

    Single spin asymmetry (SSA) is a twist-3 observable in the collinear factorization approach. We present a twist-3 single-spin-dependent cross section formula for the pion production in pp-collision, p{sup a}rrow upp->piX, relevant to RHIC experiments. In particular, we calculate the soft-fermion-pole (SFP) contribution to the cross section from the quark-gluon correlation functions. We show that its effect can be as large as the soft-gluon-pole (SGP) contribution owing to the large SFP partonic hard cross section, even though the derivative of the SFP function does not participate in the cross section.

  15. Single Scale Cluster Expansions with Applications to Many Boson and Unbounded Spin Systems

    E-print Network

    Martin Lohmann

    2014-11-04

    We develop a cluster expansion to show exponential decay of correlations for quite general single scale spin systems, as they arise in lattice quantum field theory and discretized functional integral representations for observables of quantum statistical mechanics. We apply our results to: the small field approximation to the coherent state correlation functions of the grand canonical Bose gas at negative chemical potential, constructed by Balaban, Feldman, Kn\\"orrer and Trubowitz (2010); and to N component unbounded spin systems with repulsive two body interaction and massive, possibly complex, covariance. Our cluster expansion is derived by a single application of the BKAR interpolation formula.

  16. Fabrication of a Spin-Polarized Electron Source with a Single Magnetite Whisker

    NASA Astrophysics Data System (ADS)

    Okada, Morihiro; Nagai, Shigekazu; Neo, Youichiro; Hata, Koichi; Mimura, Hidenori

    2009-06-01

    <110>-oriented single crystal magnetite whiskers 30 to 200 nm in diameter were synthesized on a stainless steel plate by means of the combustion flame thermal oxidation process. Microscopic analyses have revealed that the whiskers have some defects such as stacking faults and dislocations and also that manganese is the dominant impurity. A spin-polarized electron source with a single magnetite whisker was fabricated by using a micro-sampling instrument in a focused ion beam (FIB) system. The spin polarization of this sample was measured by using a Mott electron polarimeter and was found to be 15% at room temperature.

  17. Single Longitudinal-Spin Asymmetries in Lepton-Pair Production at RHIC and J-PARC

    E-print Network

    Hiroshi Yokoya

    2007-05-17

    We study the single longitudinal-spin asymmetries in lepton-pair production with large transverse-momentum at RHIC and J-PARC experiments. The asymmetries in the azimuthal angular distribution of a lepton can arise from an absorptive part of production amplitudes. We revisit the one-loop calculation for the absorptive part of production amplitudes in perturbative QCD, and show that the asymmetries can be sizable at RHIC and J-PARC. Measurement of the asymmetries would test the one-loop prediction for the scattering phase of this process, and provide support for a study of the single transverse-spin asymmetries in the same kinematical region.

  18. Single scale cluster expansions with applications to many Boson and unbounded spin systems

    NASA Astrophysics Data System (ADS)

    Lohmann, Martin

    2015-06-01

    We develop a cluster expansion to show exponential decay of correlations for quite general single scale spin systems, as they arise in lattice quantum field theory and discretized functional integral representations for observables of quantum statistical mechanics. We apply our results to the small field approximation to the coherent state correlation functions of the grand canonical Bose gas at negative chemical potential, constructed by Balaban et al. [Ann. Henri Poincaré 11, 151-350 (2010c)], and to N component unbounded spin systems with repulsive two body interaction and massive, possibly complex, covariance. Our cluster expansion is derived by a single application of the Brydges-Kennedy-Abdesselam-Rivasseau interpolation formula.

  19. Decoherence imaging of spin ensembles using a scanning single-electron spin in diamond

    PubMed Central

    Luan, Lan; Grinolds, Michael S.; Hong, Sungkun; Maletinsky, Patrick; Walsworth, Ronald L.; Yacoby, Amir

    2015-01-01

    The nitrogen-vacancy (NV) defect center in diamond has demonstrated great capability for nanoscale magnetic sensing and imaging for both static and periodically modulated target fields. However, it remains a challenge to detect and image randomly fluctuating magnetic fields. Recent theoretical and numerical works have outlined detection schemes that exploit changes in decoherence of the detector spin as a sensitive measure for fluctuating fields. Here we experimentally monitor the decoherence of a scanning NV center in order to image the fluctuating magnetic fields from paramagnetic impurities on an underlying diamond surface. We detect a signal corresponding to roughly 800??B in 2?s of integration time, without any control on the target spins, and obtain magnetic-field spectral information using dynamical decoupling techniques. The extracted spatial and temporal properties of the surface paramagnetic impurities provide insight to prolonging the coherence of near-surface qubits for quantum information and metrology applications. PMID:25631646

  20. Robust control of entanglement in a Nitrogen-vacancy centre coupled to a Carbon-13 nuclear spin in diamond

    E-print Network

    R. S. Said; J. Twamley

    2009-03-23

    We address a problem of generating a robust entangling gate between electronic and nuclear spins in the system of a single nitrogen-vacany centre coupled to a nearest Carbon-13 atom in diamond against certain types of systematic errors such as pulse-length and off-resonance errors. We analyse the robustness of various control schemes: sequential pulses, composite pulses and numerically-optimised pulses. We find that numerically-optimised pulses, produced by the gradient ascent pulse engineering algorithm (GRAPE), are more robust than the composite pulses and the sequential pulses. The optimised pulses can also be implemented in a faster time than the composite pulses.

  1. Direct evidence for nuclear spin waves in Nd2CuO4 by high-resolution neutron-spin-echo spectroscopy

    NASA Astrophysics Data System (ADS)

    Chatterji, Tapan; Holderer, Olaf; Schneider, Harald

    2013-11-01

    The possibility of coupling through the hyperfine interaction of nuclear spins with the electronic spin system has given rise to hope for potential novel applications in spintronics and quantum computations. We investigated the dispersion of nuclear spin waves in such a coupled system, Nd2CuO4, by using neutron-spin-echo spectroscopy at millikelvin temperatures. Our results show the existence of dispersion of nuclear spin waves in Nd2CuO4 at T = 40 mK. A fit of the dispersion data with the spin wave dispersion formula gave the Suhl-Nakamura interaction range to be of the order of 10 Å, which is much smaller than that expected theoretically.

  2. Room-temperature coherent coupling of single spins in diamond

    Microsoft Academic Search

    Torsten Gaebel; Michael Domhan; Iulian Popa; Christoffer Wittmann; Philipp Neumann; Fedor Jelezko; James R. Rabeau; Nikolas Stavrias; Andrew D. Greentree; Steven Prawer; Jan Meijer; Jason Twamley; Philip R. Hemmer; Jörg Wrachtrup

    2006-01-01

    Coherent coupling between single quantum objects is at the very heart of modern quantum physics. When the coupling is strong enough to prevail over decoherence, it can be used to engineer quantum entangled states. Entangled states have attracted widespread attention because of applications to quantum computing and long-distance quantum communication. For such applications, solid-state hosts are preferred for scalability reasons,

  3. Coherent Storage of Microwave Excitations in Rare-Earth Nuclear Spins

    NASA Astrophysics Data System (ADS)

    Wolfowicz, Gary; Maier-Flaig, Hannes; Marino, Robert; Ferrier, Alban; Vezin, Hervé; Morton, John J. L.; Goldner, Philippe

    2015-05-01

    Interfacing between various elements of a computer—from memory to processors to long range communication—will be as critical for quantum computers as it is for classical computers today. Paramagnetic rare-earth doped crystals, such as Nd3 +?Y2SiO5 (YSO ) , are excellent candidates for such a quantum interface: they are known to exhibit long optical coherence lifetimes (for communication via optical photons), possess a nuclear spin (memory), and have in addition an electron spin that can offer hybrid coupling with superconducting qubits (processing). Here we study two of these three elements, demonstrating coherent storage and retrieval between electron and Nd 145 nuclear spin states in Nd3 +?YSO . We find nuclear spin coherence times can reach 9 ms at ˜5 K , about 2 orders of magnitude longer than the electron spin coherence, while quantum state and process tomography of the storage or retrieval operation between the electron and nuclear spin reveal an average state fidelity of 0.86. The times and fidelities are expected to further improve at lower temperatures and with more homogeneous radio-frequency excitation.

  4. Coherent storage of microwave excitations in rare-earth nuclear spins.

    PubMed

    Wolfowicz, Gary; Maier-Flaig, Hannes; Marino, Robert; Ferrier, Alban; Vezin, Hervé; Morton, John J L; Goldner, Philippe

    2015-05-01

    Interfacing between various elements of a computer--from memory to processors to long range communication--will be as critical for quantum computers as it is for classical computers today. Paramagnetic rare-earth doped crystals, such as Nd(3+):Y2SiO5(YSO), are excellent candidates for such a quantum interface: they are known to exhibit long optical coherence lifetimes (for communication via optical photons), possess a nuclear spin (memory), and have in addition an electron spin that can offer hybrid coupling with superconducting qubits (processing). Here we study two of these three elements, demonstrating coherent storage and retrieval between electron and (145)Nd nuclear spin states in Nd(3+):YSO. We find nuclear spin coherence times can reach 9 ms at ?5??K, about 2 orders of magnitude longer than the electron spin coherence, while quantum state and process tomography of the storage or retrieval operation between the electron and nuclear spin reveal an average state fidelity of 0.86. The times and fidelities are expected to further improve at lower temperatures and with more homogeneous radio-frequency excitation. PMID:25978214

  5. Circuit-quantum electrodynamics with direct magnetic coupling to single-atom spin qubits in isotopically enriched {sup 28}Si

    SciTech Connect

    Tosi, Guilherme, E-mail: g.tosi@unsw.edu.au; Mohiyaddin, Fahd A.; Morello, Andrea, E-mail: a.morello@unsw.edu.au [Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia. (Australia); Huebl, Hans [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, D-85748 Garching (Germany); Nanosystems Initiative Munich (NIM), Schellingstr. 4, D-80799 Munich, Germany. (Germany)

    2014-08-15

    Recent advances in silicon nanofabrication have allowed the manipulation of spin qubits that are extremely isolated from noise sources, being therefore the semiconductor equivalent of single atoms in vacuum. We investigate the possibility of directly coupling an electron spin qubit to a superconducting resonator magnetic vacuum field. By using resonators modified to increase the vacuum magnetic field at the qubit location, and isotopically purified {sup 28}Si substrates, it is possible to achieve coupling rates faster than the single spin dephasing. This opens up new avenues for circuit-quantum electrodynamics with spins, and provides a pathway for dispersive read-out of spin qubits via superconducting resonators.

  6. Spectral Line Shape and Line Width of a Single-Mode Spin Torque Oscillator

    NASA Astrophysics Data System (ADS)

    Krivorotov, Ilya; Boone, Carl; Zhu, Jian; Cheng, Xiao; Katine, Jordan; Childress, Jeff

    2009-03-01

    Spin torque auto-oscillators are strongly nonlinear dynamical systems that are highly susceptible to external perturbations such as spin-polarized current and temperature. To understand the effect of thermal fluctuations on the oscillator dynamics, we measure power spectrum of single-mode spin torque oscillators based on a GMR nanocontact to a permalloy nanowire. Our measurements reveal deviations of the power spectral line shape from a simple Lorentzian. These deviations can be understood in terms of dephasing induced by the oscillator amplitude fluctuations. The measured spectral line shape is in a good agreement with a recent analytic theory of spin torque oscillator dynamics at a non-zero temperature [1]. We show that precise measurements of the line shape give information on important oscillator parameters such as Gilbert damping in the large-amplitude regime of current-driven magnetization dynamics. [1] V. S. Tiberkevich, A. N. Slavin, J.-V. Kim, Phys. Rev. B 78, 092401 (2008).

  7. Understanding spin structure in metallacrown single-molecule magnets using magnetic compton scattering.

    PubMed

    Deb, Aniruddha; Boron, Thaddeus T; Itou, Masayoshi; Sakurai, Yoshiharu; Mallah, Talal; Pecoraro, Vincent L; Penner-Hahn, James E

    2014-04-01

    The 3d-4f mixed metallacrowns frequently show single-molecule magnetic behavior. We have used magnetic Compton scattering to characterize the spin structure and orbital interactions in three isostructural metallacrowns: Gd2Mn4, Dy2Mn4, and Y2Mn4. These data allow the direct determination of the spin only contribution to the overall magnetic moment. We find that the lanthanide 4f spin in Gd2Mn4 and Dy2Mn4 is aligned parallel to the Mn 3d spin. For Y2Mn4 (manganese-only spin) we find evidence for spin delocalization into the O 2p orbitals. Comparing the magnetic Compton scattering data with SQUID studies that measure the total magnetic moment suggests that Gd2Mn4 and Y2Mn4 have only a small orbital contribution to the moment. In contrast, the total magnetic moment for Dy2Mn4 MCs is much larger than the spin-only moment, demonstrating a significant orbital contribution to the overall magnetic moment. Overall, these data provide direct insight into the correlation of molecular design with molecular magnetic properties. PMID:24625070

  8. Control of the cavity reflectivity using a single quantum dot spin

    NASA Astrophysics Data System (ADS)

    Sun, Shuo; Kim, Hyochul; Solomon, Glenn; Waks, Edo

    2015-03-01

    The implementation of quantum network and distributive quantum information processing relies on interaction between stationary matter qubits and flying photons. The spin of a single electron or hole confined in a quantum dot is considered as promising matter qubit as it possesses microsecond coherence time and allows picosecond timescale control using optical pulses. The quantum dot spin can also interact with a photon by controlling the optical response of a strongly coupled cavity. Yet all the experimental demonstrations of the cavity spectrum control have used neutral dots. The spin-dependent cavity spectrum for a strongly coupled charged quantum dot and cavity system has not been reported. Here, we report an experimental realization of a spin-photon interface using a strongly coupled quantum dot and cavity system. We show large modulation of the cavity reflection spectrum by manipulating the spin states of the quantum dot. The spin-photon interface is crucial for realizing a quantum logic gate or generating hybrid entanglement between a quantum dot spin and a photon. Our results represent an important step towards semiconductor based quantum logic devices and on-chip quantum networks.

  9. Nanosecond spin lifetimes in single- and few-layer graphene-hBN heterostructures at room temperature.

    PubMed

    Drögeler, Marc; Volmer, Frank; Wolter, Maik; Terrés, Bernat; Watanabe, Kenji; Taniguchi, Takashi; Güntherodt, Gernot; Stampfer, Christoph; Beschoten, Bernd

    2014-11-12

    We present a new fabrication method of graphene spin-valve devices that yields enhanced spin and charge transport properties by improving both the electrode-to-graphene and graphene-to-substrate interface. First, we prepare Co/MgO spin injection electrodes onto Si(++)/SiO2. Thereafter, we mechanically transfer a graphene-hBN heterostructure onto the prepatterned electrodes. We show that room temperature spin transport in single-, bi-, and trilayer graphene devices exhibit nanosecond spin lifetimes with spin diffusion lengths reaching 10 ?m combined with carrier mobilities exceeding 20,000 cm(2)/(V s). PMID:25291305

  10. Quantum non-demolition measurements of single donor spins in semiconductors

    E-print Network

    Sarovar, Mohan; Schenkel, Thomas; Whaley, K Birgitta

    2008-01-01

    We propose a scheme for measuring the state of a single donor electron spin using a field-effect transistor induced two-dimensional electron gas and electrically detected magnetic resonance techniques. The scheme is facilitated by hyperfine coupling to the donor nucleus. We analyze the potential sensitivity and outline experimental requirements. Our measurement provides a single-shot, projective, and effectively quantum non-demolition measurement of an electron-encoded qubit state.

  11. Quantum non-demolition measurements of single donor spins in semiconductors

    E-print Network

    Mohan Sarovar; Kevin C. Young; Thomas Schenkel; K. Birgitta Whaley

    2009-01-05

    We propose a technique for measuring the state of a single donor electron spin using a field-effect transistor induced two-dimensional electron gas and electrically detected magnetic resonance techniques. The scheme is facilitated by hyperfine coupling to the donor nucleus. We analyze the potential sensitivity and outline experimental requirements. Our measurement provides a single-shot, projective, and quantum non-demolition measurement of an electron-encoded qubit state.

  12. Initial-State Interactions and Single-Spin Asymmetries in Drell-Yan Processes

    SciTech Connect

    Brodsky, Stanley J.

    2002-06-26

    We show that the initial-state interactions from gluon exchange between the incoming quark and the target spectator system lead to leading-twist single-spin asymmetries in the Drell-Yan process H{sub 1}H{sub 2}{sup {up_arrow}} {yields} {ell}{sup +}{ell}{sup -}X. The QCD initial-state interactions produce a T-odd spin-correlation {rvec S}{sub H{sub 2}} {center_dot} {rvec P}{sub H{sub 1}} x {rvec Q} between the target spin and the virtual photon production plane which is not power-law suppressed in the Drell-Yan scaling limit at large photon virtuality Q{sup 2} at fixed x{sub F}. The single-spin asymmetry which arises from the initial-state interactions is not related to the target or projectile transversity distribution {delta}q{sub H}. The origin of the single-spin asymmetry in {pi}p{up_arrow} {ell}{sup +}{ell}{sup -} is a phase difference between two amplitudes coupling the proton target with J{sub p}{sup z} = {+-} 1/2 to the same final-state, the same amplitudes which are necessary to produce a nonzero proton anomalous magnetic moment. The calculation requires the overlap of target light-front wavefunctions with different orbital angular momentum: {Delta}L{sup z} = 1; thus the SSA in the Drell-Yan reaction provides a direct measure of orbital angular momentum in the QCD bound state. The single-spin asymmetry predicted for the Drell-Yan process {pi}p{up_arrow} {yields} {ell}{sup +}{ell}{sup -}X is similar to the single-spin asymmetries in deep inelastic semi-inclusive leptoproduction {ell}p{up_arrow} {yields} {ell}{prime}{pi}X which arises from the final-state rescattering of the outgoing quark. The Bjorken-scaling single-spin asymmetries predicted for the Drell-Yan and leptoproduction processes high-light the importance of initial- and final-state interactions for QCD observables.

  13. Single spin asymmetries in p\\uparrow p rightarrow ? X and bar{p} \\uparrow p rightarrow ? X

    NASA Astrophysics Data System (ADS)

    Zacarias, G. Domínguez; Herrera, G.; León-Monzón, I.

    2001-05-01

    We study the inclusive production of charged and neutral pions in the reactions p \\uparrow p rightarrow ? X and bar{p} \\uparrow p rightarrow ? X in the framework of single spin asymmetries. We propose a two components model where production of pions occurs both by recombination of the constituents present in the initial state and by fragmentation of quarks in the final state. Taking the Thomas precession mechanism in the recombination component into account, we obtain a good description of the experimentally observed single spin asymmetries. We show that the observed single spin asymmetries are consistent with the measured spin alignment in the polarized proton as measured by HERMES and SMC.

  14. Spin Filtering and Entanglement Swapping through Coherent Evolution of a Single Quantum Dot

    Microsoft Academic Search

    Jose Garcia Coello; Abolfazl Bayat; Sougato Bose; John H. Jefferson; Charles E. Creffield

    2010-01-01

    We exploit the non-dissipative dynamics of a pair of electrons in a large square quantum dot to perform singlet-triplet spin measurement through a single charge detection and show how this may be used for entanglement swapping and teleportation. The method is also used to generate the AKLT ground state, a further resource for quantum computation. We justify, and derive analytic

  15. The magnetic field dependence of cross-effect dynamic nuclear polarization under magic angle spinning.

    PubMed

    Mance, Deni; Gast, Peter; Huber, Martina; Baldus, Marc; Ivanov, Konstantin L

    2015-06-21

    We develop a theoretical description of Dynamic Nuclear Polarization (DNP) in solids under Magic Angle Spinning (MAS) to describe the magnetic field dependence of the DNP effect. The treatment is based on an efficient scheme for numerical solution of the Liouville-von Neumann equation, which explicitly takes into account the variation of magnetic interactions during the sample spinning. The dependence of the cross-effect MAS-DNP on various parameters, such as the hyperfine interaction, electron-electron dipolar interaction, microwave field strength, and electron spin relaxation rates, is analyzed. Electron spin relaxation rates are determined by electron paramagnetic resonance measurements, and calculations are compared to experimental data. Our results suggest that the observed nuclear magnetic resonance signal enhancements provided by MAS-DNP can be explained by discriminating between "bulk" and "core" nuclei and by taking into account the slow DNP build-up rate for the bulk nuclei. PMID:26093552

  16. Nuclear-Spin-Induced Circular Dichroism in the Infrared Region for Liquids.

    PubMed

    Chen, Fang; Yao, Guo-Hua; Zhang, Zhen-Lin; Liu, Fan-Chen; Chen, Dong-Ming

    2015-06-22

    Recently, the nuclear-spin-induced optical rotation (NSOR) and circular dichroism (NSCD) for liquids were discovered and extensively studied and developed. However, so far, nuclear-spin-induced magnetic circular dichroism in the IR region (IR-NSCD) has not been explored, even though all polyatomic molecules exhibit extensive IR spectra. Herein, IR-NSCD is proposed and discussed theoretically. The results indicate that in favorable conditions the IR-NSCD angle may be much larger than the NSOR angle in the UV/Vis region due to a vibrational resonance effect and can be measurable by using the NSOR experiment scheme. IR-NSCD can automatically combine and give NMR spectra and IRCD spectra of the nuclear spin prepolarized samples in liquids, which, in principle, could be developed to become a unique, novel analytical tool. PMID:25827496

  17. Universal Long-time Behavior of Nuclear Spin Decays in a Solid

    E-print Network

    Steven W. Morgan; Boris V. Fine; Brian Saam

    2008-05-13

    Magnetic resonance studies of nuclear spins in solids are exceptionally well suited to probe the limits of statistical physics. We report experimental results indicating that isolated macroscopic systems of interacting nuclear spins possess the following fundamental property: spin decays that start from different initial configurations quickly evolve towards the same long-time behavior. This long-time behavior is characterized by the shortest ballistic microscopic timescale of the system and therefore falls outside of the validity range for conventional approximations of statistical physics. We find that the nuclear free induction decay and different solid echoes in hyperpolarized solid xenon all exhibit sinusoidally modulated exponential long-time behavior characterized by identical time constants. This universality was previously predicted on the basis of analogy with resonances in classical chaotic systems.

  18. Perturbation of nuclear spin polarizations in solid state NMR of nitroxide-doped samples by magic-angle spinning without microwaves

    SciTech Connect

    Thurber, Kent R., E-mail: thurberk@niddk.nih.gov; Tycko, Robert [Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520 (United States)] [Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520 (United States)

    2014-05-14

    We report solid state {sup 13}C and {sup 1}H nuclear magnetic resonance (NMR) experiments with magic-angle spinning (MAS) on frozen solutions containing nitroxide-based paramagnetic dopants that indicate significant perturbations of nuclear spin polarizations without microwave irradiation. At temperatures near 25 K, {sup 1}H and cross-polarized {sup 13}C NMR signals from {sup 15}N,{sup 13}C-labeled L-alanine in trinitroxide-doped glycerol/water are reduced by factors as large as six compared to signals from samples without nitroxide doping. Without MAS or at temperatures near 100 K, differences between signals with and without nitroxide doping are much smaller. We attribute most of the reduction of NMR signals under MAS near 25 K to nuclear spin depolarization through the cross-effect dynamic nuclear polarization mechanism, in which three-spin flips drive nuclear polarizations toward equilibrium with spin polarization differences between electron pairs. When T{sub 1e} is sufficiently long relative to the MAS rotation period, the distribution of electron spin polarization across the nitroxide electron paramagnetic resonance lineshape can be very different from the corresponding distribution in a static sample at thermal equilibrium, leading to the observed effects. We describe three-spin and 3000-spin calculations that qualitatively reproduce the experimental observations.

  19. Isotope and temperature effects on nuclear magnetic shieldings and spin-rotation constants calculated at the coupled-cluster level

    NASA Astrophysics Data System (ADS)

    Gauss, Dage Sundholm Jurgen

    The temperature dependence of nuclear shieldings as well as isotope effects on shieldings and spin-rotation constants have been computationally investigated for H ,HF,F , CO, and N employing the coupled-cluster singles and doubles (CCSD) method augmented by a perturbative treatment of triple excitations (CCSD(T)) for the calculation of potential curves, shieldings and spin-rotation functions together with finite-element techniques for the solution of the rovibrational problem. Calculated and measured temperature dependence of the isotropic shieldings agrees for N , while for CO and F the computed temperature dependence is smaller 2 2 than the experimental result. Isotropic shieldings have been deduced on the basis of our calculations from the measured spin-rotation constants for four isotopomers of H and agree, as required by theory. However, calculated and measured temperature dependence of the isotope shifts between HD and D differ by up to 10% which is larger than the estimated 2 error bars for the experimental values. For HF and CO, calculated and measured isotope shifts agree, while for N no experimental data for comparison are available. In case of spin2 rotation constants, the calculated dependence on the rotational angular momentum quantum number are for both H and F in good agreement with the dependence deduced from 2 2 measurements, while for HF not enough experimental data are available for a comparison. 2 2 2 2

  20. Dynamic nuclear polarization studies of redox-sensitive nitroxyl spin probes in liposomal solution

    Microsoft Academic Search

    A. Milton Franklin Benial; Hideo Utsumi; Kazuhiro Ichikawa; Ramachandran Murugesan; Ken-Ichi Yamada; Yuichi Kinoshita; Tatsuya Naganuma; Masahisa Kato

    2010-01-01

    Overhauser-enhanced magnetic resonance imaging (OMRI) studies of a membrane-permeable nitroxyl spin probe, 2H-enriched 3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (MC-PROXYL), used in simultaneous molecular imaging is reported. Phantom imaging was performed with liposomal solutions of MC-PROXYL at varying spin probe and liposome concentrations using a field-cycle mode, custom-built OMRI scanner. Dynamic nuclear polarization (DNP) spectra of the liposomal solution of the spin probe, measured at

  1. Nuclear spin relaxation in paramagnetic systems (S>/=1) under fast rotation conditions.

    PubMed

    Kruk, Danuta; Kowalewski, Jozef

    2003-06-01

    A new theoretical model for nuclear spin relaxation in paramagnetic systems in solution has been developed. Fast rotational motion is included in the model, both as a source of modulation of the static zero-field splitting, which provides a mechanism for electron spin relaxation, and as an origin of the stochastic variation of the electron spin-nuclear spin dipole-dipole interaction leading to nuclear spin relaxation. At the limit of low magnetic field, the model is essentially identical to the earlier formulations from our laboratory, but new closed-form expressions are given for the inner- and outer-sphere relaxation at the high-field limit. Numerical comparisons with a general theory are reported for the inner-sphere case. In addition, some nuclear magnetic relaxation dispersion (NMRD) profiles from the literature are considered for systems where experiments have been done with both low-molecular weight paramagnetic complexes and their adducts with proteins. Previously developed theories are used to interpret data for the slowly rotating protein adducts, and good fits of the fast-rotating counterparts are obtained by further adjustment of one or two additional parameters. PMID:12810007

  2. Sub-optical resolution of single spins using magnetic resonance imaging at room temperature in diamond

    E-print Network

    Chang Shin; Changdong Kim; Roman Kolesov; Gopalakrishnan Balasubramanian; Fedor Jelezko; Jörg Wrachtrup; Philip R. Hemmer

    2010-03-29

    There has been much recent interest in extending the technique of magnetic resonance imaging (MRI) down to the level of single spins with sub-optical wavelength resolution. However, the signal to noise ratio for images of individual spins is usually low and this necessitates long acquisition times and low temperatures to achieve high resolution. An exception to this is the nitrogen-vacancy (NV) color center in diamond whose spin state can be detected optically at room temperature. Here we apply MRI to magnetically equivalent NV spins in order to resolve them with resolution well below the optical wavelength of the readout light. In addition, using a microwave version of MRI we achieved a resolution that is 1/270 size of the coplanar striplines, which define the effective wavelength of the microwaves that were used to excite the transition. This technique can eventually be extended to imaging of large numbers of NVs in a confocal spot and possibly to image nearby dark spins via their mutual magnetic interaction with the NV spin.

  3. Spin-1 atoms in optical superlattices: Single-atom tunneling and entanglement

    SciTech Connect

    Wagner, Andreas; Bruder, Christoph; Demler, Eugene [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Department of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States)

    2011-12-15

    We examine spinor Bose-Einstein condensates in optical superlattices theoretically using a Bose-Hubbard Hamiltonian that takes spin effects into account. Assuming that a small number of spin-1 bosons is loaded in an optical potential, we study single-particle tunneling that occurs when one lattice site is ramped up relative to a neighboring site. Spin-dependent effects modify the tunneling events in a qualitative and quantitative way. Depending on the asymmetry of the double well, different types of magnetic order occur, making the system of spin-1 bosons in an optical superlattice a model for mesoscopic magnetism. We use a double-well potential as a unit cell for a one-dimensional superlattice. Homogeneous and inhomogeneous magnetic fields are applied, and the effects of the linear and the quadratic Zeeman shifts are examined. We also investigate the bipartite entanglement between the sites and construct states of maximal entanglement. The entanglement in our system is due to both orbital and spin degrees of freedom. We calculate the contribution of orbital and spin entanglements and show that the sum of these two terms gives a lower bound for the total entanglement.

  4. Stability of spin-electric coupling in triangular single-molecule magnets under external contacts

    NASA Astrophysics Data System (ADS)

    Islam, Fhokrul; Nossa, Javier; Canali, Carlo; Pederson, Mark

    2015-03-01

    Triangular single molecule magnets (SMMs) with antiferromagnetic exchange coupling exhibit Kramer degenerate chiral spin-doublets ground states, which can be efficiently coupled by an electric field, even in the absence of spin-orbit interaction. Recent first-principles calculations show that unsupported V3 SMM has giant spin-electric coupling corresponding to dipole moment of about one tenth of the water-molecule dipole moment. The corresponding Rabi time for electric switching between two chiral states can be on the order of one nano-second for reasonable electric fields, which makes these molecules very attractive candidates for storing and manipulating pairs of coupled spin-chiral qbits. However, for device applications of the spin-electric coupling, these frustrated SMMs need to be supported on a surface or between metallic leads. Preserving this effect in an external environment is a challenging problem requiring appropriate functionalization. In this talk we will discuss the stability of the spin-electric coupling in V3 SMM when coupled to gold leads or deposited on a graphene surface.

  5. Large-Spin and Large-Winding Expansions of Giant Magnons and Single Spikes

    E-print Network

    Emmanuel Floratos; Georgios Linardopoulos

    2015-05-30

    We generalize the method of our recent paper on the large-spin expansions of Gubser-Klebanov-Polyakov (GKP) strings to the large-spin and large-winding expansions of finite-size giant magnons and finite-size single spikes. By expressing the energies of long open strings in RxS2 in terms of Lambert's W-function, we compute the leading, subleading and next-to-subleading series of classical exponential corrections to the dispersion relations of Hofman-Maldacena giant magnons and infinite-winding single spikes. We also compute the corresponding expansions in the doubled regions of giant magnons and single spikes that are respectively obtained when their angular and linear velocities become smaller or greater than unity.

  6. Effect of nuclear spin symmetry in cold and ultracold reactions: D + para/ortho-H2

    NASA Astrophysics Data System (ADS)

    Simbotin, Ionel; Côté, Robin

    2015-06-01

    We report results for reaction and vibrational quenching of the collision D with para-H2(v,j=0) and ortho-H2(v,j=1) at cold and ultracold temperatures. We investigate the effect of nuclear spin symmetry for barrier dominated processes (0?slant v?slant 4) and for one barrierless case (v = 5). We find resonant structures for energies in the range corresponding to 0.01–10 K, which depend on the nuclear spin of H2, arising from contributions of specific partial waves. We discuss the implications on the results in this benchmark system for ultracold chemistry.

  7. Electrically driven reverse overhauser pumping of nuclear spins in quantum dots.

    PubMed

    Rudner, M S; Levitov, L S

    2007-12-14

    We propose a new mechanism for polarizing nuclear spins in quantum dots, based on periodic modulation of the hyperfine coupling by electric driving at the electron spin resonance frequency. Dynamical nuclear polarization results from resonant excitation rather than hyperfine relaxation mediated by a thermal bath, and thus is not subject to Overhauser-like detailed balance constraints. This allows polarization in the direction opposite to that expected from the Overhauser effect. Competition of the electrically driven and bath-assisted mechanisms can give rise to spatial modulation and sign reversal of polarization on a scale smaller than the electron confinement radius in the dot. PMID:18233468

  8. Simultaneous sub-second hyperpolarization of the nuclear and electron spins of phosphorus in silicon

    E-print Network

    A. Yang; M. Steger; T. Sekiguchi; M. L. W. Thewalt; T. D. Ladd; K. M. Itoh; H. Riemann; N. V. Abrosimov; P. Becker; H. -J. Pohl

    2009-08-12

    We demonstrate a method which can hyperpolarize both the electron and nuclear spins of 31P donors in Si at low field, where both would be essentially unpolarized in equilibrium. It is based on the selective ionization of donors in a specific hyperfine state by optically pumping donor bound exciton hyperfine transitions, which can be spectrally resolved in 28Si. Electron and nuclear polarizations of 90% and 76%, respectively, are obtained in less than a second, providing an initialization mechanism for qubits based on these spins, and enabling further ESR and NMR studies on dilute 31P in 28Si.

  9. Final-state interaction as origin of single-spin asymmetry in semi-inclusive DIS

    SciTech Connect

    Hwang, D.S. [Department of Physics, Sejong University, Seoul 143-747 (Korea, Republic of)

    2005-05-06

    Recent measurements from the HERMES, SMC, CLAS and COMPASS collaborations show a remarkably large azimuthal single-spin asymmetries of the proton in semi-inclusive pion leptoproduction {gamma}*(q)p{up_arrow} {yields} {pi}X. The existence of such single-spin asymmetries requires a phase difference between two amplitudes coupling the proton target with J{sub p}{sup z} = {+-}(1/2) to the same final-state, the same amplitudes which are necessary to produce a nonzero proton anomalous magnetic moment. We show that the exchange of gauge particles between the outgoing quark and the proton spectators produces a Coulomb-like complex phase which depends on the angular momentum Lz of the proton's constituents and is thus distinct for different proton spin amplitudes. We then find that final-state interactions from gluon exchange between the outgoing quark and the target spectator system lead to single-spin asymmetries at leading twist in perturbative QCD; i.e., the rescattering corrections are not power-law suppressed at large photon virtuality Q2 at fixed xbj.

  10. Single-shot readout and relaxation measurements in exchange coupled 31 P electron spins in silicon

    NASA Astrophysics Data System (ADS)

    Dehollain, Juan Pablo; Muhonen, Juha; Tan, Kuan; Saraiva, Andre; Jamieson, David; Dzurak, Andrew; Morello, Andrea

    2015-03-01

    We present the experimental observation of a large exchange coupling J ~ 300 ?eV between two 31 P electron spin qubits in silicon. The singlet and triplet states of the coupled spins are monitored in real time by a single-electron transistor, which detects ionization from tunnel-rate-dependent processes in the coupled spin system, yielding single-shot readout fidelities above 95%. The triplet to singlet relaxation time T1 ~ 4 ms at zero magnetic field agrees with the theoretical prediction for the observed J-coupling energy in 31 P dimers in silicon. The three order of magnitude increase in relaxation rate compared to single donors, is caused by a hyperfine interaction mediated mixing of the singlet and triplet states. Additionally, the time evolution of the two-electron state populations reveals an inversion in the energetic hierarchy of the valley-orbit excited states, which had been theoretically predicted for donor pairs with < 6 nm separation. These results pave the way to the realization of two-qubit quantum logic gates with spins in silicon and highlight the necessity to adopt gating schemes compatible with weak J-coupling strengths.

  11. Electronic spin transport and spin precession in single graphene layers at room temperature

    Microsoft Academic Search

    Nikolaos Tombros; Csaba Jozsa; Mihaita Popinciuc; Harry T. Jonkman; Bart J. van Wees

    2007-01-01

    Electronic transport in single or a few layers of graphene is the subject of intense interest at present. The specific band structure of graphene, with its unique valley structure and Dirac neutrality point separating hole states from electron states, has led to the observation of new electronic transport phenomena such as anomalously quantized Hall effects, absence of weak localization and

  12. Transverse single spin asymmetry in Drell-Yan production in polarized pA collisions

    E-print Network

    Zhou, Jian

    2015-01-01

    We study the transverse single spin asymmetry in Drell-Yan production in pA collisions with incoming protons being transversely polarized. We carry out the calculation using a newly developed hybrid approach. The polarized cross section computed in the hybrid approach is consistent with that obtained from the usual TMD factorization at low transverse momentum as expected, whereas at high transverse momentum, color entanglement effect is found to play a role in contributing to the spin asymmetry of Drell-Yan production, though it is a $1/N_c^2$ suppressed effect.

  13. Observation of a Single-Spin Azimuthal Asymmetry in Semi-Inclusive Pion Electro-Production

    Microsoft Academic Search

    A. Airapetian; N. Akopov; M. Amarian; E. C. Aschenauer; H. Avakian; R. Avakian; A. Avetissian; E. Avetissian; B. Bains; C. Baumgarten; M. Beckmann; S. Belostotski; J. E. Belz; S. Bernreuther; N. Bianchi; J. Blouw; H. Bottcher; A. Borissov; M. Bouwhuis; J. Brack; S. Brauksiepe; B. Braun; B. Bray; W. Bruckner; A. Brull; E. E. W. Bruins; H. J. Bulten; G. P. Capitani; P. Chumney; E. Cisbani; P. F. Dalpiaz; E. De Sanctis; D. De Schepper; E. Devitsin; A. Dvoredsky; G. Elbakian; J. Ely; A. Fantoni; A. Fechtchenko; M. Ferstl; K. Fiedler; B. W. Filippone; H. Fischer; B. Fox; J. Franz; S. Frullani; M.-A. Funk; Y. Garber; H. Gao; F. Garibaldi; G. Gavrilov; P. Geiger; V. Gharibyan; A. Golendukhin; G. Graw; O. Grebeniouk; L. G. Greeniaus; C. Grosshauser; M. Guidal; A. Gute; V. Gyurjyan; W. Haeberli; J.-O. Hansen; M. Hartig; D. Hasch; O. Hausser; F. H. Heinsius; R. Henderson; M. Henoch; R. Hertenberger; Y. Holler; R. J. Holt; W. Hoprich; H. Ihssen; M. Iodice; A. Izotov; H. E. Jackson; A. Jgoun; R. Kaiser; E. Kinney; A. Kisselev; P. Kitching; H. Kobayashi; N. Koch; K. Konigsmann; M. Kolstein; H. Kolster; V. Korotkov; W. Korsch; V. Kozlov; L. H. Kramer; V. G. Krivokhijine; M. Kurisuno; G. Kyle; W. Lachnit; P. Lenisa; W. Lorenzon; N. C. R. Makins; F. K. Martens; J. W. Martin; F. Masoli; A. Mateos; M. McAndrew; K. McIlhany; R. D. McKeown; F. Meissner; A. Metz; N. Meyners; O. Mikloukho; C. A. Miller; M. A. Miller; R. Milner; V. Muccifora; R. Mussa; A. Nagaitsev; Y. Naryshkin; A. M. Nathan; F. Neunreither; M. Niczyporuk; W.-D. Nowak; M. Nupieri; K. A. Oganessyan; T. G. O'Neill; R. Openshaw; J. Ouyang; B. R. Owen; V. Papavassiliou; S. F. Pate; M. Pitt; S. Potashov; D. H. Potterveld; G. Rakness; A. Reali; R. Redwine; A. R. Reolon; R. Ristinen; K. Rith; P. Rossi; S. Rudnitsky; M. Ruh; D. Ryckbosch; Y. Sakemi; I. Savin; C. Scarlett; A. Schafer; F. Schmidt; H. Schmitt; G. Schnell; K. P. Schuler; A. Schwind; J. Seibert; T.-A. Shibata; K. Shibatani; T. Shin; V. Shutov; C. Simani; A. Simon; K. Sinram; P. Slavich; M. Spengos; E. Steens; J. Stenger; J. Stewart; U. Stoesslein; M. Sutter; H. Tallini; S. Taroian; A. Terkulov; O. Teryaev; E. Thomas; B. Tipton; M. Tytgat; G. M. Urciuoli; G. van der Steenhoven; R. van de Vyver; J. J. van Hunen; M. C. Vetterli; V. Vikhrov; M. G. Vincter; J. Visser; E. Volk; W. Wander; J. Wendland; S. E. Williamson; T. Wise; K. Woller; S. Yoneyama; H. Zohrabian

    1999-01-01

    Single-spin asymmetries for semi-inclusive pion production in deep-inelastic\\u000ascattering have been measured for the first time. A significant target-spin\\u000aasymmetry of the distribution in the azimuthal angle phi of the pion relative\\u000ato the lepton scattering plane was observed for pi+ electro-production on a\\u000alongitudinally polarized hydrogen target. The corresponding analyzing power in\\u000athe sin(phi) moment of the cross section

  14. Neutron diffraction determination of the nuclear spin ordering in Cu and Ag at nano- and subnano-K temperatures (invited)

    Microsoft Academic Search

    M. Steiner; A. Metz; K. Siemensmeyer; O. V. Lounasmaa; J. T. Tuoriniemi; K. K. Nummila; R. T. Vuorinen; K. N. Clausen; K. Lefmann; F. B. Rasmussen

    1996-01-01

    The spontaneous nuclear spin ordering in the simple diamagnetic metals Cu and Ag has been studied by neutron diffraction using the spin dependent part of the nuclear cross section. Simple antiferromagnetic ordering of type I has been found in zero field for these fcc-systems below 60 and 560 pK for Cu and Ag, respectively. The ordering in an applied field

  15. Observation and characterization of intermolecular homonuclear single-quantum coherences in liquid nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Chen, Zhong; Chen, Zhiwei; Zhong, Jianhui

    2002-11-01

    Intermolecular zero-quantum and double-quantum coherences (iZQCs and iDQCs) are frequently discussed in literature since they may provide novel contrast mechanisms in magnetic resonance imaging and possibilities for high-resolution spectra in an inhomogeneous and unstable magnetic field. In a previous paper [J. Chem. Phys. 115, 10769 (2001)], we have studied both theoretically and experimentally the properties of iZQC and iDQC nuclear magnetic resonance (NMR) signals related to intermolecular dipolar interactions in two-component systems. In this paper, the investigation is extended to homonuclear intermolecular single-quantum coherences (iSQCs) from the second-order spin interactions, which have not been observed and studied previously. Selective excitation was used to suppress the strong conventional single-spin single-quantum signals. A combination of dipolar field treatment and Torrey equation was used to derive a general theoretical expression for the time evolution of spins with arbitrary flip angles of rf pulses. The expression was used to predict the optimal conditions for iSQCs among highly polarized spins in liquid. Dependence of the iSQC signals on the experimental parameters was measured and analyzed to verify the theoretical predictions. For the first time, signals from pure homonuclear two-spin iSQCs free of much larger conventional single-spin single-quantum signals, and intermolecular iSQC cross peaks in homonuclear pulsed-field gradient COSY experiments were observed and characterized, in one- and two-dimensional (1D and 2D) experiments, respectively. The use of coherence-selection gradients tilted at the magic angle results in the suppression of iSQC cross peaks. It provides strong evidence that the observed signals originate from distant dipolar interactions. Relaxation and diffusion properties of iSQCs in multiple-component samples were characterized and analyzed as well as the optimal rf flip angles. Theoretical and experimental results presented herein demonstrate that the signals from the homonuclear second-order iSQCs not only have a similar signal intensity as iZQCs or iDQCs, all of which are much stronger than that from three-spin iSQCs reported previously, but also provide spatial information related to dipolar correlation scales similar to iZQCs and iDQCs, which is not present in conventional SQC experiments. All 1D and 2D NMR experimental observations based on single- and multiple-component samples are in excellent agreement with the theoretical predictions. The quantitative study of iSQCs provides a better understanding of their unique mechanisms, and may find useful applications in NMR analyses such as sample purification and/or preparation of metabolites, biofluids, and natural compounds dissolved in nondeuterated solvents.

  16. Relativistic hybrid density functional calculations of indirect nuclear spin-spin coupling tensors - Comparison with experiment for diatomic alkali metal halides 1 , 2

    Microsoft Academic Search

    David L. Bryce; Jochen Autschbach

    2009-01-01

    The accurate calculation of the isotropic (Jiso) and anisotropic (DJ) parts of indirect nuclear spin-spin coupling tensors is a stringent test for quantum chemistry, particularly for couplings involving heavy isotopes where relativistic ef- fects and relativity - electron correlation cross terms are expected to play an important role. Experimental measurements on diatomic molecules in the gas phase offer ideal data

  17. Charge and spin pumping effects in a single-dot Aharonov-Bohm ring with ferromagnetic leads

    NASA Astrophysics Data System (ADS)

    Pan, Hui; Xu, Huai-Zhe; Lü, Rong

    2010-11-01

    The pumping of electrons through a single-dot Aharonov-Bohm ring attached to ferromagnetic leads are investigated theoretically by using the nonequilibrium Green's function method. It is found that the charge and spin pumping effects at zero-bias voltage can be produced by an oscillating electric field applied to the quantum dot. The pumped charge and spin currents through the single-dot ring are analyzed for two cases: (i) the single-dot ring is connected with two ferromagnetic leads and (ii) the single-dot ring is connected with a ferromagnetic and a normal-metal lead. For the former case, a pure spin current can be generated due to the photon-assisted tunneling effects. For the latter case, both the charge and spin current can be pumped in opposite directions. The control of the pumped spin and charge current by using the magnetic flux through the ring is also discussed.

  18. Spin relaxation in graphene quantum dots

    Microsoft Academic Search

    Guido Burkard; Philipp Struck

    2010-01-01

    With its low concentration of nuclear spins and relatively weak spin-orbit coupling, graphene is a promising host material for electron spin qubits. We have calculated the spin relaxation time T1 of a single spin in graphene quantum dots [1,2] as a function of the externally applied magnetic field B. We find that in quantum dots without coupling between the valleys

  19. Measurement of Single and Double Spin Asymmetries in Deep Inelastic Pion Electroproduction with a Longitudinally Polarized Target

    SciTech Connect

    Avakian, H; Bosted, P; Elouadrhiri, L; Adhikari, K P; Aghasyan, M; Amaryan, M; Anghinolfi, M; Baghdasaryan, H; Ball, J; Battaglieri, M; Bedlinskiy, I; Biselli, A S; Branford, D; Briscoe, W J; Brooks, W; Carman, D S; Casey, L; Cole, P L; Collins, P; Crabb, D; Crede, V; D& #x27; Angelo, A; Daniel, A; Dashyan, N; DeVita, R; DeSanctis, E; Deur, A; Dey, B; Dhamija, S; Dickson, R; Djalali, C; Dodge, G; Doughty, D; Dupre, R; El Alaoui, A; Eugenio, P; Fegan, S; Fersch, M; Guler, N; Guo, L; Hafidi, K; Hakobyan, H; Hanretty, C; Hassall, N; Heddle, D; Hicks, K; Holtrop, M; Ilieva, Y; Ireland, D G; Isupov, E L; Jawalkar, S S; Jo, H S; Joo, K; Keller, D; Khandaker, M; Khetarpal,; Kim, W; Klein, A; Klein, F J; Konczykowski, P; Kubarovsky, V; Kuhn, S E; Kuleshov, S V; Kuznetsov, V; Livingston, K; Lu, H Y; Markov, N; Mayer, M; McAndrew, J; McCracken, M E; McKInnon, B; Meyer, C A; Mineeva, T; Mirazita, M; Mokeev, V; Moreno, B; Moriya, K; Morrison, B; Moutarde, H; Munevar, E; Nadel-Turonski, P; Nasseripour, R; Niccolai, S; Niculescu, G; Niculescu, I; Niroula, M R; Osipenko, M; Ostrovidov, A I; Paremuzyan, R; Park, K; Park, S; Pasyuk, E; Anefalos Pereira, S; Perrin, Y; Pisano, S; Pogorelko, O; Price, J W; Procureur, S; Prok, Protopopescu; Raue, B A; Ricco, G; Ripani, M; Rosner, G; Rossi, P; Sabatie, F; Saini, M S; Salamanca, J; Salgado, C; Schumacher, R A; Seder, E; Seraydaryan, H; Sharabian, Y G; Sober, D I; Sokhan, D; Stapanyan, S S; Stepanyan, S; Stoler, P; Strauch, S; Suleiman, R; Taiuti, M; Tedeschi, D J; Tkachenko, S; Ungaro, M; Vernarsky, B; Vineyard, M F; Voutier, E; Watts, D P; Weinstein, L B; Weygand, D P; Wood, M H; Zhang, J; Zhao, B

    2010-12-01

    We report the first measurement of the transverse momentum dependence of double spin asymmetries in semi-inclusive production of pions in deep inelastic scattering off the longitudinally polarized proton. Data have been obtained using a polarized electron beam of 5.7 GeV with the CLAS detector at the Thomas Jefferson National Accelerator Facility (JLab). A significant non-zero $\\sin2\\phi$ single spin asymmetry was also observed for the first time indicating strong spin-orbit correlations for transversely polarized quarks in the longitudinally polarized proton. The azimuthal modulations of single spin asymmetries have been measured over a wide kinematic range.

  20. Spin polarized asymmetric nuclear matter and neutron star matter within the lowest order constrained variational method

    SciTech Connect

    Bordbar, G. H. [Department of Physics, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha, P. O. Box 55134-441, Maragha (Iran, Islamic Republic of); Bigdeli, M. [Department of Physics, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of); Department of Physics, Zanjan University, Zanjan (Iran, Islamic Republic of)

    2008-01-15

    In this paper, we calculate properties of the spin polarized asymmetrical nuclear matter and neutron star matter, using the lowest order constrained variational (LOCV) method with the AV{sub 18}, Reid93, UV{sub 14}, and AV{sub 14} potentials. According to our results, the spontaneous phase transition to a ferromagnetic state in the asymmetrical nuclear matter as well as neutron star matter do not occur.

  1. Coupled nuclear spin relaxation and internal rotations in magnesium fluosilicate hexahydrate.

    NASA Technical Reports Server (NTRS)

    Utton, D. B.; Tsang, T.

    1972-01-01

    Both proton and fluorine nuclear spin-lattice relaxations have been studied by the 180- to 90-deg pulse method in magnesium fluosilicate hexahydrate at 25 and 13 MHz over the temperature range from 170 to 350 K. Observed nonexponential behavior of the nuclear magnetic relaxation is explained by internal rotations of the doubly charged negative fluosilicate ions and doubly charged positive magnesium hexahydrate ions.

  2. Evidence for a Single-Spin Azimuthal Asymmetry in Semi-inclusive Pion Electroproduction

    SciTech Connect

    Airapetian, A. [Yerevan Physics Institute, 375036, Yerevan, (Armenia)] [Yerevan Physics Institute, 375036, Yerevan, (Armenia); Akopov, N. [Yerevan Physics Institute, 375036, Yerevan, (Armenia)] [Yerevan Physics Institute, 375036, Yerevan, (Armenia); Amarian, M. [Nationaal Instituut voor Kernfysica en Hoge-Energiefysica (NIKHEF), 1009 DB Amsterdam, The Netherlands (Netherlands) [Nationaal Instituut voor Kernfysica en Hoge-Energiefysica (NIKHEF), 1009 DB Amsterdam, The Netherlands (Netherlands); Istituto Nazionale di Fisica Nucleare, Sezione Sanita and Physics Laboratory, Istituto Superiore di Sanita, 00161 Roma, (Italy); Yerevan Physics Institute, 375036, Yerevan, (Armenia); Aschenauer, E. C. [Department of Subatomic and Radiation Physics, University of Gent, 9000 Gent, (Belgium) [Department of Subatomic and Radiation Physics, University of Gent, 9000 Gent, (Belgium); Max-Planck-Institut fuer Kernphysik, 69029 Heidelberg, (Germany); DESY Zeuthen, 15738 Zeuthen, (Germany); Avakian, H. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, 00044 Frascati, (Italy)] [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, 00044 Frascati, (Italy); Avakian, R. [Yerevan Physics Institute, 375036, Yerevan, (Armenia)] [Yerevan Physics Institute, 375036, Yerevan, (Armenia); Avetissian, A. [Yerevan Physics Institute, 375036, Yerevan, (Armenia)] [Yerevan Physics Institute, 375036, Yerevan, (Armenia); Avetissian, E. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, 00044 Frascati, (Italy) [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, 00044 Frascati, (Italy); Bains, B. [Department of Physics, University of Illinois, Urbana, Illinois 61801 (United States)] [Department of Physics, University of Illinois, Urbana, Illinois 61801 (United States); Baumgarten, C. [Sektion Physik, Universitaet Muenchen, 85748 Garching, (Germany)] (and others) [Sektion Physik, Universitaet Muenchen, 85748 Garching, (Germany)

    2000-05-01

    Single-spin asymmetries for semi-inclusive pion production in deep-inelastic scattering have been measured for the first time. A significant target-spin asymmetry of the distribution in the azimuthal angle {phi} of the pion relative to the lepton scattering plane was formed for {pi}{sup +} electroproduction on a longitudinally polarized hydrogen target. The corresponding analyzing power in the sin {phi} moment of the cross section is 0.022{+-}0.005{+-}0.003 . This result can be interpreted as the effect of terms in the cross section involving chiral-odd spin distribution functions in combination with a chiral-odd fragmentation function that is sensitive to the transverse polarization of the fragmenting quark. (c) 2000 The American Physical Society.

  3. Measurement of the Berry Phase in a Single Solid-State Spin Qubit

    E-print Network

    Kai Zhang; Naufer M. Nusran; Bradley R. Slezak; M. V. Gurudev Dutt

    2015-04-10

    We present measurements of the Berry Phase in a single solid-state spin qubit associated with the nitrogen-vacancy center in diamond. Our results demonstrate the remarkable degree of coherent control achievable in the presence of a highly complex solid-state environment. We manipulate the spin qubit geometrically by careful application of microwave radiation that creates an effective rotating magnetic field, and observe the resulting phase via spin-echo interferometry. We find good agreement with Berry's predictions within experimental errors. We also investigated the role of the environment on the geometric phase, and observed that unlike other solid-state qubit systems, the dephasing was primarily dominated by fast radial fluctuations in the path.

  4. A Magnetic Switch for Spin-Catalyzed Interconversion of Nuclear Spin Yongjun Li,

    E-print Network

    Turro, Nicholas J.

    equilibrium at RT: (1) adsorbing a sample of eH2@C60 on the external surface of NaY zeolite at RT; (2) cooling% oH2/50% pH2 mixture (which is eH2 at 77 K); (4) removing the spin catalyst (O2) by applying a vacuumH2@C60 takes days in the absence of an added spin catalyst. The conversion of *pH2@C60 to eH2@C60 (eq

  5. Coherent storage of microwave excitations in rare-earth nuclear spins

    E-print Network

    Gary Wolfowicz; Hannes Maier-Flaig; Robert Marino; Alban Ferrier; Hervé Vezin; John J. L. Morton; Philippe Goldner

    2014-12-23

    Interfacing between various elements of a computer - from memory to processors to long range communication - will be as critical for quantum computers as it is for classical computers today. Paramagnetic rare earth doped crystals, such as Nd$^{3+}$:Y$_2$SiO$_5$ (YSO), are excellent candidates for such a quantum interface: they are known to exhibit long optical coherence lifetimes (for communication via optical photons), possess a nuclear spin (memory) and have in addition an electron spin that can offer hybrid coupling with superconducting qubits (processing). Here we study two of these three elements, demonstrating coherent storage and retrieval between electron and $^{145}$Nd nuclear spin states in Nd$^{3+}$:YSO. We find nuclear spin coherence times can reach 9 ms at $\\approx 5$ K, about two orders of magnitude longer than the electron spin coherence, while quantum state and process tomography of the storage/retrieval operation reveal an average state fidelity of 0.86. The times and fidelities are expected to further improve at lower temperatures and with more homogeneous radio-frequency excitation.

  6. Dynamic nuclear polarization studies of redox-sensitive nitroxyl spin probes in liposomal solution.

    PubMed

    Benial, A Milton Franklin; Utsumi, Hideo; Ichikawa, Kazuhiro; Murugesan, Ramachandran; Yamada, Ken-ichi; Kinoshita, Yuichi; Naganuma, Tatsuya; Kato, Masahisa

    2010-05-01

    Overhauser-enhanced magnetic resonance imaging (OMRI) studies of a membrane-permeable nitroxyl spin probe, (2)H-enriched 3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (MC-PROXYL), used in simultaneous molecular imaging is reported. Phantom imaging was performed with liposomal solutions of MC-PROXYL at varying spin probe and liposome concentrations using a field-cycle mode, custom-built OMRI scanner. Dynamic nuclear polarization (DNP) spectra of the liposomal solution of the spin probe, measured at 14.529mT using a 5mT sweep of the electron paramagnetic resonance (EPR) irradiation field showed splitting of the low and high filed hyperfine lines. Spectral measurements using D(2)O and a spin broadening agent, K(3)Fe(CN)(6) confirmed that these peaks originated from water molecules in two different environments, compartmentalized with liposomes. The nuclear Overhauser enhancement measured at different EPR irradiation times and power levels showed reduction in water nuclear magnetic resonance (NMR) signal enhancement in liposomal membrane due to the reduction in the coupling constant, rho. This study illustrates that OMRI can be used to differentiate between the intra- and extra- membrane water by loading the liposome vesicles with a lipid-permeable nitroxyl spin probe. PMID:20226702

  7. Dynamic nuclear polarization studies of redox-sensitive nitroxyl spin probes in liposomal solution

    NASA Astrophysics Data System (ADS)

    Benial, A. Milton Franklin; Utsumi, Hideo; Ichikawa, Kazuhiro; Murugesan, Ramachandran; Yamada, Ken-ichi; Kinoshita, Yuichi; Naganuma, Tatsuya; Kato, Masahisa

    2010-05-01

    Overhauser-enhanced magnetic resonance imaging (OMRI) studies of a membrane-permeable nitroxyl spin probe, 2H-enriched 3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (MC-PROXYL), used in simultaneous molecular imaging is reported. Phantom imaging was performed with liposomal solutions of MC-PROXYL at varying spin probe and liposome concentrations using a field-cycle mode, custom-built OMRI scanner. Dynamic nuclear polarization (DNP) spectra of the liposomal solution of the spin probe, measured at 14.529 mT using a 5 mT sweep of the electron paramagnetic resonance (EPR) irradiation field showed splitting of the low and high filed hyperfine lines. Spectral measurements using D 2O and a spin broadening agent, K 3Fe(CN) 6 confirmed that these peaks originated from water molecules in two different environments, compartmentalized with liposomes. The nuclear Overhauser enhancement measured at different EPR irradiation times and power levels showed reduction in water nuclear magnetic resonance (NMR) signal enhancement in liposomal membrane due to the reduction in the coupling constant, ?. This study illustrates that OMRI can be used to differentiate between the intra- and extra- membrane water by loading the liposome vesicles with a lipid-permeable nitroxyl spin probe.

  8. Chip-Scale Nanofabrication of Single Spins and Spin Arrays in Diamond

    SciTech Connect

    Toyli, David M.; Weis, Christoph D.; Fuchs, D.; Schenkel, Thomas; Awschalom, David D.

    2010-07-02

    We demonstrate a technique to nanofabricate nitrogen vacancy (NV) centers in diamond based on broad-beam nitrogen implantation through apertures in electron beam lithography resist. This method enables high-throughput nanofabrication of single NV centers on sub-100-nm length scales. Secondary ion mass spectroscopy measurements facilitate depth profiling of the implanted nitrogen to provide three-dimensional characterization of the NV center spatial distribution. Measurements of NV center coherence with on-chip coplanar waveguides suggest a pathway for incorporating this scalable nanofabrication technique in future quantum applications.

  9. Spin states in semiconductor quantum dot with a single magnetic ion

    NASA Astrophysics Data System (ADS)

    Li, X. J.; Yang, W.; Chang, Kai; Xia, J. B.

    2008-09-01

    We investigate theoretically CdTe quantum dots containing a single Mn impurity, including the sp-d exchange interaction between carriers and the magnetic ion and the short-range exchange interaction between electron and hole. We find anticrossing behaviors in the energy spectrum of the electron-hole (e-h) pair that arise from the interplay between exchange interactions and the magnetic field. In addition to the s-d exchange interaction, we find that other mechanisms inducing the anticrossings become important in the strong heavy hole-light hole ( hh- lh) mixing regime. The transition strengths between the states with spin projection of Mn ion Sz?-5/2 (Sz=-5/2) decrease (increase) with increasing magnetic fields due to the alignment of the Mn spin. The spin splitting of the e-h pair states depends sensitively on the external magnetic and electric field, which reveals useful information about the spin orientation and position of the magnetic ion. Meanwhile, the manipulation of the position of the magnetic ion offers us a way to control the spin splitting of the carriers.

  10. Cotunneling signatures of spin-electric coupling in frustrated triangular single-molecule magnets

    NASA Astrophysics Data System (ADS)

    Nossa, Javier; Canali, Carlo

    2013-03-01

    The ground state (GS) of frustrated (antiferromagnetic) triangular single-molecule magnets is characterized by two total-spin S = 1 /2 doublets with opposite chirality. According to a group theory analysis [M. Trif et al., Phys. Rev. Lett. 101, 217201 (2008)] an external electric field can efficiently couple these two chiral spin states, even when the spin-orbit interaction (SOI) is absent. The strength of this coupling, d, is determined by an off-diagonal matrix element of the dipole operator, which can be calculated by ab-initio methods [M. F. Islam et al., Phys. Rev. B 82, 155446 (2010)]. In this work we propose that Coulomb-blockade transport experiments in the cotunneling regime can provide a direct way to determine the spin-electric coupling strength. Indeed, an electric field generates a d-dependent splitting of the GS manifold, which can be detected in the inelastic cotunneling conductance. Our theoretical analysis is supported by master-equation calculations of quantum transport in the cotunneling regime. We employ a Hubbard-model approach to elucidate the relationship between the Hubbard parameters t and U, and the spin-electric coupling constant d . This allows us to predict the regime in which the coupling constant d can be extracted from experiment.

  11. Theory of nuclear magnetic spin-rotational relaxation for asymmetric molecules

    Microsoft Academic Search

    James McConnell

    1988-01-01

    A stochastic differential equation study of nuclear magnetic relaxation by spin-rotational interactions was successfully completed for spherical, symmetric rotator and linear molecules. This theory has now been extended to asymmetric rotator molecules by first establishing the conditions under which such an extension is mathematically feasible and then investigating the consequences of accepting these conditions.

  12. Semiconductor quantum computer design with 100 nm separation of nuclear-spin qubits

    E-print Network

    Privman, Vladimir

    at distances of order 100 nm, attainable with the present-day semiconductor-heterostructure device technologies down, T1 = O(103 ) sec. Fig. 1. Schematic illustration of a semiconductor heterostructure quantumSemiconductor quantum computer design with 100 nm separation of nuclear-spin qubits Vladimir

  13. Nuclear Quadrupole Spin-Lattice Relaxation and Critical Dynamics of Ferroelectric Crystals

    Microsoft Academic Search

    G. Bonera; F. Borsa; A. Rigamonti

    1970-01-01

    The effect on the nuclear spin-lattice relaxation of the anomalous temperature dependence of generalized unstable lattice modes near the ferroelectric transition is investigated both theoretically and experimentally. Expressions for the relaxation rate near Tc are derived for typical cases of critical dynamics of ferroelectric crystals. For the case of undamped soft-phonon modes it is shown that, on the basis of

  14. Nuclear spin dependence of the reaction of H3+ with H2. I. Kinetics and modeling

    NASA Astrophysics Data System (ADS)

    Crabtree, Kyle N.; Tom, Brian A.; McCall, Benjamin J.

    2011-05-01

    The chemical reaction H_3^+ + H2 ? H2 + H_3^+ is the simplest bimolecular reaction involving a polyatomic, yet is complex enough that exact quantum mechanical calculations to adequately model its dynamics are still unfeasible. In particular, the branching fractions for the "identity," "proton hop," and "hydrogen exchange" reaction pathways are unknown, and to date, experimental measurements of this process have been limited. In this work, the nuclear-spin-dependent steady-state kinetics of the H_3^+ + H2 reaction is examined in detail, and employed to generate models of the ortho:para ratio of H_3^+ formed in plasmas of varying ortho:para H2 ratios. One model is based entirely on nuclear spin statistics, and is appropriate for temperatures high enough to populate a large number of H_3^+ rotational states. Efforts are made to include the influence of three-body collisions in this model by deriving nuclear spin product branching fractions for the H_5^+ + H2 reaction. Another model, based on rate coefficients calculated using a microcanonical statistical approach, is appropriate for lower-temperature plasmas in which energetic considerations begin to compete with the nuclear spin branching fractions. These models serve as a theoretical framework for interpreting the results of laboratory studies on the reaction of H_3^+ with H2.

  15. A Search for Nonstandard Neutron Spin Interactions using Dual Species Xenon Nuclear Magnetic Resonance

    NASA Astrophysics Data System (ADS)

    Bulatowicz, Michael; Larsen, Michael; Mirijanian, James; Fu, Changbo; Yan, Haiyang; Smith, Erick; Snow, Mike; Walker, Thad

    2012-06-01

    NMR measurements using polarized noble gases can constrain possible exotic spin-dependent interactions involving nucleons. A differential measurement insensitive to magnetic field fluctuations can be performed using a mixture of two polarized species with different ratios of nucleon spin to magnetic moment. We used the NMR cell test station at Northrop Grumman Corporation (NGC) (developed to evaluate dual species xenon vapor cells for the Nuclear Magnetic Resonance Gyroscope) to search for NMR frequency shifts of xenon-129 and xenon-131 when a non-magnetic zirconia rod is modulated near the NMR cell. We simultaneously excited both Xe isotopes and detected free-induction-decay transients. In combination with theoretical calculations of the neutron spin contribution to the nuclear angular momentum, the measurements put a new upper bound on possible monopole-dipole interactions of the neutron for ranges around 1mm. This work is supported by the NGC Internal Research and Development (IRAD) funding, the Department of Energy, and the NSF.

  16. Solid effect in magic angle spinning dynamic nuclear polarization

    E-print Network

    Smith, Albert A.

    For over five decades, the solid effect (SE) has been heavily utilized as a mechanism for performing dynamic nuclear polarization (DNP). Nevertheless, it has not found widespread application in contemporary, high magnetic ...

  17. EFFECTS OF NUCLEAR SPIN POLARIZATION ON REACTION DYNAMICS IN PHOTOSYNTHETIC

    E-print Network

    Boxer, Steven G.

    in -200 ps (Rockley et al., 1975; Kaufmann et al., 1975). To study P+I* it is useful to block this latter- cally induced dynamic nuclear polarization [CIDNP]) (Kaptein and Oosterhoff, 1969; Closs, 1969

  18. Nuclear Spin Relaxation and Molecular Interactions of a Novel Triazolium-Based Ionic Liquid

    SciTech Connect

    Allen, Jesse J.; Schneider, Yanika; Kail, Brian W.; Luebke, David R.; Nulwala, Hunaid; Damodaran, Krishnan

    2013-04-11

    Nuclear spin relaxation, small-angle X-ray scattering (SAXS), and electrospray ionization mass spectrometry (ESI-MS) techniques are used to determine supramolecular arrangement of 3-methyl-1-octyl-4-phenyl-1H-triazol-1,2,3-ium bis(trifluoromethanesulfonyl)imide [OMPhTz][Tf{sub 2}N], an example of a triazolium-based ionic liquid. The results obtained showed first-order thermodynamic dependence for nuclear spin relaxation of the anion. First-order relaxation dependence is interpreted as through-bond dipolar relaxation. Greater than first-order dependence was found in the aliphatic protons, aromatic carbons (including nearest neighbors), and carbons at the end of the aliphatic tail. Greater than first order thermodynamic dependence of spin relaxation rates is interpreted as relaxation resulting from at least one mechanism additional to through-bond dipolar relaxation. In rigid portions of the cation, an additional spin relaxation mechanism is attributed to anisotropic effects, while greater than first order thermodynamic dependence of the octyl side chain’s spin relaxation rates is attributed to cation–cation interactions. Little interaction between the anion and the cation was observed by spin relaxation studies or by ESI-MS. No extended supramolecular structure was observed in this study, which was further supported by MS and SAXS. nuclear Overhauser enhancement (NOE) factors are used in conjunction with spin–lattice relaxation time (T{sub 1}) measurements to calculate rotational correlation times for C–H bonds (the time it takes for the vector represented by the bond between the two atoms to rotate by one radian). The rotational correlation times are used to represent segmental reorientation dynamics of the cation. A combination of techniques is used to determine the segmental interactions and dynamics of this example of a triazolium-based ionic liquid.

  19. Electron Spin Resonance of Irradiated Single Crystals of l-phenylalanine-HCl

    Microsoft Academic Search

    Edwin L. Fasanella; Walter Gordy

    1969-01-01

    Single crystals of L-phenylalanine-HCl have been observed with electron spin resonance after irradiation with a cobalt 60 gamma -ray source. The predominant signals observed are from long-lived benzyl radicals. The results indicate that one form of radiation damage to proteins containing this amino acid is breakage of the carbon-carbon bond to release the benzyl radical from the polypeptide chain. Hyperfine

  20. Electron Spin Resonance Study of ?-Irradiated Single Crystals of Semicarbazide Hydrochloride

    Microsoft Academic Search

    Keshav N. Shrivastava; Roy S. Anderson

    1968-01-01

    Electron spin resonance studies of ?-irradiated single crystals of semicarbazide hydrochloride and the deuterated form, ND2CONHND3+·Cl?, revealed the presence of the stably trapped ·N(?)H(?) ? N(?)H(?)3+ radical obtained by C&sngbnd;N bond rupture of the parent molecule. The principal g values were gaa = 2.0041 ± 0.0003, gbb = 2.0023, and gcc = 2.0044. The principal elements of the hyperfine couplings

  1. Morphologic Parameters of Normal Swallowing Events Using Single-Shot Fast Spin Echo Dynamic MRI

    Microsoft Academic Search

    Dana M. Hartl; Marcella Albiter; Frédéric Kolb; Bernard Luboinski; Robert Sigal

    2003-01-01

    This study was designed to determine visible and measurable morphological parameters in normal swallowing using dynamic MRI with single-shot fast spin echo (SSFSE), as a preliminary study in view of noninvasive MRI swallowing evaluation in patients with dysphagia. Seven healthy volunteers aged 24–40 underwent dynamic MRI with SSFSE, with a 1.5-T unit, using a head and neck antenna. Patients repeated

  2. Anisotropy of the low temperature resistivity of hexagonal single crystalline spin glass systems

    Microsoft Academic Search

    H. Albrecht; H. Meierling; E. F. Wassermann; H. Zähres; F. T. Hedgcock

    1982-01-01

    The impurity contribution to the resistivity in zero field (T) of dilute hexagonal single crystals of ZnMn, CdMn and MgMn has been studied in the mK range on samples cut parallel () and perpendicular () to thec-axis, using a SQUID technique for the measurements. Typical spin glass behavior is found in (T) as well as (T) for all alloys, with

  3. Spin Filtering and Entanglement Swapping through Coherent Evolution of a Single Quantum Dot

    Microsoft Academic Search

    Jose Garcia Coello; Abolfazl Bayat; Sougato Bose; John H. Jefferson; Charles E. Creffield

    2010-01-01

    We exploit the nondissipative dynamics of a pair of electrons in a large square quantum dot to perform singlet-triplet spin measurement through a single charge detection and show how this may be used for entanglement swapping and teleportation. The method is also used to generate the Affleck-Kennedy-Lieb-Tasaki ground state, a further resource for quantum computation. We justify, and derive analytic

  4. Spin Filtering and Entanglement Swapping through Coherent Evolution of a Single Quantum Dot

    Microsoft Academic Search

    Jose Garcia Coello; Abolfazl Bayat; Sougato Bose; John H. Jefferson; Charles E. Creffield

    2010-01-01

    We exploit the non-dissipative dynamics of a pair of electrons in a large\\u000asquare quantum dot to perform singlet-triplet spin measurement through a single\\u000acharge detection and show how this may be used for entanglement swapping and\\u000ateleportation. The method is also used to generate the AKLT ground state, a\\u000afurther resource for quantum computation. We justify, and derive analytic

  5. Non-Markovian dynamics of a single-mode cavity strongly coupled to an inhomogeneously broadened spin ensemble

    E-print Network

    Dmitry O. Krimer; Stefan Putz; Johannes Majer; Stefan Rotter

    2014-10-02

    We study the dynamics of a spin ensemble strongly coupled to a single-mode resonator driven by external pulses. When the mean frequency of the spin ensemble is in resonance with the cavity mode, damped Rabi oscillations are found between the spin ensemble and the cavity mode which we describe very accurately, including the dephasing effect of the inhomogeneous spin broadening. We demonstrate that a precise knowledge of this broadening is crucial both for a qualitative and a quantitative understanding of the temporal spin-cavity dynamics. On this basis we show that coherent oscillations between the spin ensemble and the cavity can be enhanced by a few orders of magnitude, when driving the system with pulses that match special resonance conditions. Our theoretical approach is tested successfully with an experiment based on an ensemble of negatively charged nitrogen-vacancy (NV) centers in diamond strongly coupled to a superconducting coplanar single-mode waveguide resonator.

  6. Non-Markovian dynamics of a single-mode cavity strongly coupled to an inhomogeneously broadened spin ensemble

    NASA Astrophysics Data System (ADS)

    Krimer, Dmitry O.; Putz, Stefan; Majer, Johannes; Rotter, Stefan

    2014-10-01

    We study the dynamics of a spin ensemble strongly coupled to a single-mode resonator driven by external pulses. When the mean frequency of the spin ensemble is in resonance with the cavity mode, damped Rabi oscillations are found between the spin ensemble and the cavity mode which we describe very accurately, including the dephasing effect of the inhomogeneous spin broadening. We demonstrate that a precise knowledge of this broadening is crucial both for a qualitative and a quantitative understanding of the temporal spin-cavity dynamics. On this basis we show that coherent oscillations between the spin ensemble and the cavity can be enhanced by a few orders of magnitude, when driving the system with pulses that match special resonance conditions. Our theoretical approach is tested successfully with an experiment based on an ensemble of negatively charged nitrogen-vacancy centers in diamond strongly coupled to a superconducting coplanar single-mode waveguide resonator.

  7. Doping controlled spin reorientation in dysprosium-samarium orthoferrite single crystals

    NASA Astrophysics Data System (ADS)

    Cao, Shixun; Zhao, Weiyao; Kang, Baojuan; Zhang, Jincang; Ren, Wei

    2015-03-01

    As one of the most important phase transitions, spin reorientation (SR) in rare earth transition metal oxides draws much attention of emerging materials technologies. The origin of SR is the competition between different spin configurations which possess different free energy. We report the control of spin reorientation (SR) transition in perovskite rare earth orthoferrite Dy1-xSmxFeO3, a whole family of single crystals grown by optical floating zone method from x =0 to 1. Temperature dependence of the magnetizations under zero-field-cooling (ZFC) and field-cooling (FC) processes are studied. We have found a remarkable linear change of SR transition temperature in Sm-rich samples for x>0.2, which covers an extremely wide temperature range including room temperature. The a-axis magnetization curves under FCC process bifurcate from and then jump down to that of warming process (ZFC and FCW curves) in single crystals when x =0.5-0.9, suggesting complicated 4f-3d electron interactions among Dy3+-Sm3+, Dy3+-Fe3+, and Sm3+-Fe3+ sublattices of diverse magnetic configurations for materials physics and design. The magnetic properties and the doping effect on SR transition temperature in these single crystals might be useful in the spintronics device application. This work is supported by the National Key Basic Research Program of China (Grant No. 2015CB921600), and the National Natural Science Foundation of China (NSFC, Nos. 51372149, 50932003, 11274222).

  8. Gate control of single-electron spins: a multi-scale numerical simulation approach

    NASA Astrophysics Data System (ADS)

    Prabhakar, Sanjay; Raynolds, James

    2008-03-01

    Among recent proposals for next-generation, non-charge-based logic is the notion that a single electron can be trapped and its spin manipulated through the application of gate voltages (Rev. Mod. Phys. 79, 1217 (2007)). In this talk we present numerical simulations of such Spin Single Electron Transistors (SSET) in support of experimental work at the University at Albany, State University of New York aimed at the practical development of post-CMOS concepts and devices. We use a multi-scale simulation strategy to self-consistently solve the Schroedinger-Poisson equations (with and without exchange-correlation effects) to obtain realistic confining and gating potentials for realistic device geometries. We discuss scaling of the equations in the various sub domains of a finite-element discretization to span the dimensions from the micron scale of the gate structures down the single-electron level. We will discuss the calculation of the gate-tuned ``g-factor" for electrons and holes (Phys. Rev. B 68, 155330 (2003)) in electro-statically- and lithographically-defined quantum dots including the Rashba and Dresselhaus spin-orbit interactions computed numerically from realistic wave functions. This work is supported through funding from the DARPA/NRI INDEX center.

  9. Addressing a single spin in diamond with a macroscopic dielectric microwave cavity

    SciTech Connect

    Le Floch, J.-M.; Tobar, M. E. [ARC Centre of Excellence for Engineered Quantum Systems, School of Physics, The University of Western Australia, Crawley, Western Australia 6009 (Australia); Bradac, C.; Nand, N.; Volz, T. [ARC Centre of Excellence for Engineered Quantum Systems, Department of Physics and Astronomy, Macquarie University, North Ryde, New South Wales 2109 (Australia); Castelletto, S. [School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Melbourne (Australia)

    2014-09-29

    We present a technique for addressing single nitrogen-vacancy (NV) center spins in diamond over macroscopic distances using a tunable dielectric microwave cavity. We demonstrate optically detected magnetic resonance (ODMR) for a single negatively charged NV center (NV{sup –}) in a nanodiamond (ND) located directly under the macroscopic microwave cavity. By moving the cavity relative to the ND, we record the ODMR signal as a function of position, mapping out the distribution of the cavity magnetic field along one axis. In addition, we argue that our system could be used to determine the orientation of the NV{sup –} major axis in a straightforward manner.

  10. Nuclear magnetic relaxation induced by exchange-mediated orientational randomization: Longitudinal relaxation dispersion for a dipole-coupled spin-1/2 pair

    NASA Astrophysics Data System (ADS)

    Chang, Zhiwei; Halle, Bertil

    2013-10-01

    In complex biological or colloidal samples, magnetic relaxation dispersion (MRD) experiments using the field-cycling technique can characterize molecular motions on time scales ranging from nanoseconds to microseconds, provided that a rigorous theory of nuclear spin relaxation is available. In gels, cross-linked proteins, and biological tissues, where an immobilized macromolecular component coexists with a mobile solvent phase, nuclear spins residing in solvent (or cosolvent) species relax predominantly via exchange-mediated orientational randomization (EMOR) of anisotropic nuclear (electric quadrupole or magnetic dipole) couplings. The physical or chemical exchange processes that dominate the MRD typically occur on a time scale of microseconds or longer, where the conventional perturbation theory of spin relaxation breaks down. There is thus a need for a more general relaxation theory. Such a theory, based on the stochastic Liouville equation (SLE) for the EMOR mechanism, is available for a single quadrupolar spin I = 1. Here, we present the corresponding theory for a dipole-coupled spin-1/2 pair. To our knowledge, this is the first treatment of dipolar MRD outside the motional-narrowing regime. Based on an analytical solution of the spatial part of the SLE, we show how the integral longitudinal relaxation rate can be computed efficiently. Both like and unlike spins, with selective or non-selective excitation, are treated. For the experimentally important dilute regime, where only a small fraction of the spin pairs are immobilized, we obtain simple analytical expressions for the auto-relaxation and cross-relaxation rates which generalize the well-known Solomon equations. These generalized results will be useful in biophysical studies, e.g., of intermittent protein dynamics. In addition, they represent a first step towards a rigorous theory of water 1H relaxation in biological tissues, which is a prerequisite for unravelling the molecular basis of soft-tissue contrast in clinical magnetic resonance imaging.

  11. PHYSICAL REVIEW A 88, 063802 (2013) Generating entangled spin states for quantum metrology by single-photon detection

    E-print Network

    Vuletic, Vladan

    2013-01-01

    by single-photon detection Robert McConnell,1 Hao Zhang,1 Senka ´Cuk,1,2 Jiazhong Hu,1 Monika H. Schleier, entangled, non-Gaussian states of collective spin in large atomic ensembles by means of single-photon [25] which have been experimentally implemented for photon-pair and single-photon generation [26

  12. SingleSpin Asymmetries in SemiInclusive DeepInelastic Scattering on a TransverselyPolarized Hydrogen Target

    E-print Network

    Single­Spin Asymmetries in Semi­Inclusive Deep­Inelastic Scattering on a Transversely to this intrinsic rotation of the nu­ cleon. The investigation of the nucleon's spin structure is the main task#erence between such a deep inelastic scattering (DIS) event and an elastic scattering event in which the nucleon

  13. Single-Spin Asymmetries in Semi-Inclusive Deep-Inelastic Scattering on a Transversely-Polarized Hydrogen Target

    E-print Network

    Single-Spin Asymmetries in Semi-Inclusive Deep-Inelastic Scattering on a Transversely to this intrinsic rotation of the nu- cleon. The investigation of the nucleon's spin structure is the main task between such a deep inelastic scattering (DIS) event and an elastic scattering event in which the nucleon

  14. Nuclear spin–lattice relaxation in periodically irradiated systems

    Microsoft Academic Search

    A. J. Vega; R. W. Vaughan

    1978-01-01

    A master equation for nuclear magnetic relaxation under conditions of periodic and cyclic rf irradiation is derived based on the stochastic Liouville equation. Conditions for the validity of the equation, involving both use of the motional narrowing approximation and the Magnus expansion, are discussed with particular attention given to the simultaneous presence of fluctuating and nonfluctuating interactions. The expressions derived

  15. Disorder-enhanced nuclear spin relaxation at Landau level filling factor one

    NASA Astrophysics Data System (ADS)

    Guan, Tong; Benedikt, Friess; Li, Yong-Qing; Yan, Shi-Shen; Vladimir, Umansky; Klaus von, Klitzing; Jurgen, H. Smet

    2015-06-01

    The nuclear spin relaxation rate (1/T1) is measured for GaAs two-dimensional (2D) electron systems in the quantum Hall regime with an all-electrical technique for agitating and probing the nuclear spins. A “tilted plateau” feature is observed near the Landau level filling factor ? = 1 in 1/T1 versus ?. Both the width and magnitude of the plateau increase with decreasing electron density. At low temperatures, 1/T1 exhibits an Arrhenius temperature dependence within the tilted plateau regime. The extracted energy gaps are up to two orders of magnitude smaller than the corresponding charge transport gaps. These results point to a nontrivial mechanism for the disorder-enhanced nuclear spin relaxation, in which microscopic inhomogeneities play a key role for the low energy spin excitations related to skyrmions. Project supported by the National Basic Research Program of China (Grant Nos. 2012CB921703 and 2015CB921102), the National Natural Science Foundation of China (Grant Nos. 91121003, 11374337, and 61425015), the Chinese Academy of Sciences, the BMBF, and the German–Israel Foundation.

  16. Single spin asymmetries of inclusive hadrons produced in electron scattering from a transversely polarized [superscript 3]He target

    E-print Network

    Allada, Kalyan C.

    We report the first measurement of target single spin asymmetries (A[subscript N]) in the inclusive hadron production reaction, e + [superscript 3]He[superscript ?] ? h + X, using a transversely polarized [superscript 3]He ...

  17. A new sample environment for cryogenic nuclear resonance scattering experiments on single crystals and microsamples at P01, PETRA III

    NASA Astrophysics Data System (ADS)

    Rackwitz, Sergej; Faus, Isabelle; Schmitz, Markus; Kelm, Harald; Krüger, Hans-Jörg; Andersson, K. Kristoffer; Hersleth, Hans-Petter; Achterhold, Klaus; Schlage, Kai; Wille, Hans-Christian; Schünemann, Volker; Wolny, Juliusz A.

    2014-04-01

    In order to carry out orientation dependent nuclear resonance scattering (NRS) experiments on small single crystals of e.g. iron proteins and/or chemical complexes but also on surfaces and other micrometer-sized samples a 2-circle goniometer including sample positioning optics has been installed at beamline P01, PETRA III, DESY, Hamburg. This sample environment is now available for all users of this beamline. Sample cooling is performed with a cryogenic gas stream which allows NRS measurements in the temperature range from 80 up to 400 K. In a first test this new sample environment has been used in order to investigate the orientation dependence of the nuclear inelastic scattering (NIS) signature of (i) a dinuclear iron(II) spin crossover (SCO) system and (ii) a hydrogen peroxide treated metmyoglobin single crystal.

  18. PUBLISHED ONLINE: 10 MAY 2009 | DOI: 10.1038/NPHYS1273 Breakdown of the nuclear-spin-temperature

    E-print Network

    Loss, Daniel

    adiabatic demagnetization techniques borrowed from bulk nuclear magnetic resonance experiments3 wouldLETTERS PUBLISHED ONLINE: 10 MAY 2009 | DOI: 10.1038/NPHYS1273 Breakdown of the nuclear of interacting nuclear spins arranged on a crystalline lattice is generally described using a thermody- namic

  19. Parametric analysis of plastic strain and force distribution in single pass metal spinning

    NASA Astrophysics Data System (ADS)

    Choudhary, Shashank; Tejesh, Chiruvolu Mohan; Regalla, Srinivasa Prakash; Suresh, Kurra

    2013-12-01

    Metal spinning also known as spin forming is one of the sheet metal working processes by which an axis-symmetric part can be formed from a flat sheet metal blank. Parts are produced by pressing a blunt edged tool or roller on to the blank which in turn is mounted on a rotating mandrel. This paper discusses about the setting up a 3-D finite element simulation of single pass metal spinning in LS-Dyna. Four parameters were considered namely blank thickness, roller nose radius, feed ratio and mandrel speed and the variation in forces and plastic strain were analysed using the full-factorial design of experiments (DOE) method of simulation experiments. For some of these DOE runs, physical experiments on extra deep drawing (EDD) sheet metal were carried out using En31 tool on a lathe machine. Simulation results are able to predict the zone of unsafe thinning in the sheet and high forming forces that are hint to the necessity for less-expensive and semi-automated machine tools to help the household and small scale spinning workers widely prevalent in India.

  20. Observation and electric current control of a local spin in a single-molecule magnet

    PubMed Central

    Komeda, Tadahiro; Isshiki, Hironari; Liu, Jie; Zhang, Yan-Feng; Lorente, Nicolás; Katoh, Keiichi; Breedlove, Brian K.; Yamashita, Masahiro

    2011-01-01

    In molecular spintronics, the spin state of a molecule may be switched on and off by changing the molecular structure. Here, we switch on and off the molecular spin of a double-decker bis(phthalocyaninato)terbium(III) complex (TbPc2) adsorbed on an Au(111) surface by applying an electric current via a scanning tunnelling microscope. The dI/dV curve of the tunnelling current recorded onto a TbPc2 molecule shows a Kondo peak, the origin of which is an unpaired spin of a ?-orbital of a phthalocyaninato (Pc) ligand. By applying controlled current pulses, we could rotate the upper Pc ligand in TbPc2, leading to the disappearance and reappearance of the Kondo resonance. The rotation shifts the molecular frontier-orbital energies, quenching the ?-electron spin. Reversible switching between two stable ligand orientations by applying a current pulse should make it possible to code information at the single-molecule level. PMID:21364556

  1. Quantifying Nucleoporin Stoichiometry Inside Single Nuclear Pore Complexes In vivo

    NASA Astrophysics Data System (ADS)

    Mi, Lan; Goryaynov, Alexander; Lindquist, Andre; Rexach, Michael; Yang, Weidong

    2015-03-01

    The nuclear pore complex (NPC) is one of the largest supramolecular structures in eukaryotic cells. Its octagonal ring-scaffold perforates the nuclear envelope and features a unique molecular machinery that regulates nucleocytoplasmic transport. NPCs are composed of ~30 different nucleoporins (Nups), averaged at 8, 16 or 32 copies per NPC. This estimate has not been confirmed for individual NPCs in living cells due to the inherent difficulty of counting proteins inside single supramolecular complexes. Here we used single-molecule SPEED microscopy to directly count the copy-number of twenty-four different Nups within individual NPCs of live yeast, and found agreement as well as significant deviation from previous estimates. As expected, we counted 8 copies of four peripheral Nups and 16 copies of fourteen scaffold Nups. Unexpectedly, we counted a maximum of 16 copies of Nsp1 and Nic96, rather than 32 as previously estimated; and found only 10-15 copies of six other Nups, rather than 8 or 16 copies as expected. This in situ molecular-counting technology can test structure-function models of NPCs and other supramolecular structures in cells.

  2. Large-gap quantum spin Hall insulator in single layer bismuth monobromide Bi4Br4.

    PubMed

    Zhou, Jin-Jian; Feng, Wanxiang; Liu, Cheng-Cheng; Guan, Shan; Yao, Yugui

    2014-08-13

    Quantum spin Hall (QSH) insulators have gapless topological edge states inside the bulk band gap, which can serve as dissipationless spin current channels. The major challenge currently is to find suitable materials for this topological state. Here, we predict a new large-gap QSH insulator with bulk direct band gap of ? 0.18 eV, in single-layer Bi4Br4, which could be exfoliated from its three-dimensional bulk material due to the weakly bonded layered structure. The band gap of single-layer Bi4Br4 is tunable via strain engineering, and the QSH phase is robust against external strain. Moreover, because this material consists of special one-dimensional molecular chain as its basic building block, the single layer Bi4Br4 could be torn to ribbons with clean and atomically sharp edges. These nanoribbons, which have single-Dirac-cone edge states crossing the bulk band gap, are ideal wires for dissipationless transport. Our work thus provides a new promising material for experimental studies and practical applications of the QSH effect. PMID:25058154

  3. Phonon induced spin relaxation times of single donors and donor clusters in silicon

    NASA Astrophysics Data System (ADS)

    Hsueh, Yuling; Buch, Holger; Hollenberg, Lloyd; Simmons, Michelle; Klimeck, Gerhard; Rahman, Rajib

    2014-03-01

    The phonon induced relaxation times (T1) of electron spins bound to single phosphorous (P) donors and P donor clusters in silicon is computed using the atomistic tight-binding method. The electron-phonon Hamiltonian is directly computed from the strain dependent tight-binding Hamiltonian, and the relaxation time is computed from Fermi's Golden Rule using the donor states and the electron-phonon Hamiltonian. The self-consistent Hartree method is used to compute the multi-electron wavefunctions in donor clusters. The method takes into account the full band structure of silicon including the spin-orbit interaction, and captures both valley repopulation and single valley g-factor shifts in a unified framework. The single donor relaxation rate varies proportionally to B5, and is of the order of seconds at B =2T, both in good agreement with experimental single donor data (A. Morello et. al., Nature 467, 687 (2010)). T1 calculations in donor clusters show variations for different electron numbers and donor numbers and locations. The computed T1 in a 4P:5e donor cluster match well with a scanning tunneling microscope patterned P donor cluster (H. Buch et. al., Nature Communications 4, 2017 (2013)).

  4. Charge and spin pumping effects in a single-dot Aharonov–Bohm ring with ferromagnetic leads

    Microsoft Academic Search

    Hui Pan; Huai-Zhe Xu; Rong Lü

    2010-01-01

    The pumping of electrons through a single-dot Aharonov–Bohm ring attached to ferromagnetic leads are investigated theoretically by using the nonequilibrium Green's function method. It is found that the charge and spin pumping effects at zero-bias voltage can be produced by an oscillating electric field applied to the quantum dot. The pumped charge and spin currents through the single-dot ring are

  5. Analysis of state-of-the-art single-thruster attitude control techniques for spinning penetrator

    NASA Astrophysics Data System (ADS)

    Raus, Robin; Gao, Yang; Wu, Yunhua; Watt, Mark

    2012-07-01

    The attitude dynamics and manoeuvre survey in this paper is performed for a mission scenario involving a penetrator-type spacecraft: an axisymmetric prolate spacecraft spinning around its minor axis of inertia performing a 90° spin axis reorientation manoeuvre. In contrast to most existing spacecraft only one attitude control thruster is available, providing a control torque perpendicular to the spin axis. Having only one attitude thruster on a spinning spacecraft could be preferred for spacecraft simplicity (lower mass, lower power consumption etc.), or it could be imposed in the context of redundancy/contingency operations. This constraint does yield restrictions on the thruster timings, depending on the ratio of minor to major moments of inertia among other parameters. The Japanese Lunar-A penetrator spacecraft proposal is a good example of such a single-thruster spin-stabilised prolate spacecraft. The attitude dynamics of a spinning rigid body are first investigated analytically, then expanded for the specific case of a prolate and axisymmetric rigid body and finally a cursory exploration of non-rigid body dynamics is made. Next two well-known techniques for manoeuvring a spin-stabilised spacecraft, the Half-cone/Multiple Half-cone and the Rhumb line slew, are compared with two new techniques, the Sector-Arc Slew developed by Astrium Satellites and the Dual-cone developed at Surrey Space Centre. Each technique is introduced and characterised by means of simulation results and illustrations based on the penetrator mission scenario and a brief robustness analysis is performed against errors in moments of inertia and spin rate. Also, the relative benefits of each slew algorithm are discussed in terms of slew accuracy, energy (propellant) efficiency and time efficiency. For example, a sequence of half-cone manoeuvres (a Multi-half-cone manoeuvre) tends to be more energy-efficient than one half-cone for the same final slew angle, but more time-consuming. As another example, the new Sector-Arc Slew and Dual-cone techniques are designed to overcome a specific restriction on attainable slew angle that is associated with the half-cone manoeuvre, giving one additional degree of freedom for designers to fine-tune.

  6. Measurement of W+/- boson single-spin asymmetry in transversely polarized pp collisions at STAR

    NASA Astrophysics Data System (ADS)

    Smirnov, Dmitri; Fazio, Salvatore; STAR Collaboration

    2013-10-01

    TMeasurement of W+/- boson single-spin asymmetry in transversely polarized pp collisions at STARhe Sivers function f1T ? describes the correlation of parton transverse momentum with the transverse spin of the nucleon. There is evidence of a quark Sivers effect in semi-inclusive DIS (SIDIS) measurements. Important aspects of the Sivers effect include its process dependence and the color gauge invariance. As a consequence, the quark Sivers functions are of opposite sign in SIDIS and in Drell-Yan and this non-universality is a fundamental prediction from the gauge invariance of QCD. The experimental test of this sign change is one of the open questions in hadronic physics, and can provide a direct verification of QCD factorization. While luminosities required for a meaningful measurement of asymmetries in Drell-Yan production are challenging, W+/- production with a comparable sensitivity to the predicted sign change can be measured at the STAR experiment. At these large Q2 the result can also provide essential input for the evolution effects of the Sivers function. We report on the first attempt to measure the transverse single spin asymmetry, AN, of the W+/- boson at RHIC. The W kinematics is reconstructed by employing MC-based corrections dictated.

  7. Single-spin asymmetries in semi-inclusive deep inelastic scattering and Drell-Yan processes

    NASA Astrophysics Data System (ADS)

    Brodsky, Stanley J.; Hwang, Dae Sung; Kovchegov, Yuri V.; Schmidt, Ivan; Sievert, Matthew D.

    2013-07-01

    We examine in detail the diagrammatic mechanisms which provide the change of sign between the single transverse spin asymmetries measured in semi-inclusive deep inelastic scattering (SIDIS) and in the Drell-Yan process (DY). This asymmetry is known to arise due to the transverse spin dependence of the target proton combined with a T-odd complex phase. Using the discrete symmetry properties of transverse spinors, we show that the required complex phase originates in the denominators of rescattering diagrams and their respective cuts. For simplicity, we work in a model where the proton consists of a valence quark and a scalar diquark. We then show that the phases generated in SIDIS and in DY originate from distinctly different cuts in the amplitudes, which at first appears to obscure the relationship between the single-spin asymmetries in the two processes. Nevertheless, further analysis demonstrates that the contributions of these cuts are identical in the leading-twist Bjorken kinematics considered, resulting in the standard sign-flip relation between the Sivers functions in SIDIS and DY. Physically, this fundamental, but yet untested, prediction occurs because the Sivers effect in the Drell-Yan reaction is modified by the initial-state “lensing” interactions of the annihilating antiquark, in contrast to the final-state lensing which produces the Sivers effect in deep inelastic scattering.

  8. Nuclear Configurations in the Spin-Orbit Coupling Model. I. Empirical Evidence

    Microsoft Academic Search

    Maria Goeppert Mayer

    1950-01-01

    An extreme one particle model of the nucleus is proposed. The model is based on the succession of energy levels of a single particle in a potential between that of a three-dimensional harmonic oscillator and a square well. (1) Strong spin orbit coupling leading to inverted doublets is assumed. (2) An even number of identical nucleons are assumed to couple

  9. Preparation of Non-equilibrium Nuclear Spin States in Double Quantum Dots

    E-print Network

    M. Gullans; J. J. Krich; J. M. Taylor; B. I. Halperin; M. D. Lukin

    2014-07-25

    We theoretically study the dynamic polarization of lattice nuclear spins in GaAs double quantum dots containing two electrons. In our prior work [Phys. Rev. Lett. 104, 226807 (2010)] we identified three regimes of long-term dynamics, including the build up of a large difference in the Overhauser fields across the dots, the saturation of the nuclear polarization process associated with formation of so-called "dark states," and the elimination of the difference field. In particular, when the dots are different sizes we found that the Overhauser field becomes larger in the smaller dot. Here we present a detailed theoretical analysis of these problems including a model of the polarization dynamics and the development of a new numerical method to efficiently simulate semiclassical central-spin problems. When nuclear spin noise is included, the results agree with our prior work indicating that large difference fields and dark states are stable configurations, while the elimination of the difference field is unstable; however, in the absence of noise we find all three steady states are achieved depending on parameters. These results are in good agreement with dynamic nuclear polarization experiments in double quantum dots.

  10. Gd-based single-ion magnets with tunable magnetic anisotropy: molecular design of spin qubits.

    PubMed

    Martínez-Pérez, M J; Cardona-Serra, S; Schlegel, C; Moro, F; Alonso, P J; Prima-García, H; Clemente-Juan, J M; Evangelisti, M; Gaita-Ariño, A; Sesé, J; van Slageren, J; Coronado, E; Luis, F

    2012-06-15

    We report ac susceptibility and continuous wave and pulsed EPR experiments performed on GdW10 and GdW30 polyoxometalate clusters, in which a Gd3+ ion is coordinated to different polyoxometalate moieties. Despite the isotropic character of gadolinium as a free ion, these molecules show slow magnetic relaxation at very low temperatures, characteristic of single molecule magnets. For T?200??mK, the spin-lattice relaxation becomes dominated by pure quantum tunneling events, with rates that agree quantitatively with those predicted by the Prokof'ev and Stamp model [Phys. Rev. Lett. 80, 5794 (1998)]. The sign of the magnetic anisotropy, the energy level splittings, and the tunneling rates strongly depend on the molecular structure. We argue that GdW30 molecules are also promising spin qubits with a coherence figure of merit Q(M)?50. PMID:23004325

  11. Spin-Filtering and Entanglement Swapping through Coherent Evolution of a Single Quantum Dot

    E-print Network

    Coello, Jose Garcia; Bose, Sougato; Jefferson, John H; Creffield, Charles E

    2010-01-01

    We exploit the non-dissipative dynamics of a pair of electrons in a large square quantum dot to perform singlet-triplet spin measurement through a single charge detection and show how this may be used for entanglement swapping and teleportation. The method is also used to generate the AKLT ground state, a further resource for quantum computation. We justify, and derive analytic results for, an effective charge-spin Hamiltonian which is valid over a wide range of parameters and agrees well with exact numerical results of a realistic effective-mass model. Our analysis also indicates that the method is robust to choice of dot-size and initialization errors, as well as decoherence introduced by the hyperfine interaction.

  12. Spin filtering and entanglement swapping through coherent evolution of a single quantum dot.

    PubMed

    Coello, Jose Garcia; Bayat, Abolfazl; Bose, Sougato; Jefferson, John H; Creffield, Charles E

    2010-08-20

    We exploit the nondissipative dynamics of a pair of electrons in a large square quantum dot to perform singlet-triplet spin measurement through a single charge detection and show how this may be used for entanglement swapping and teleportation. The method is also used to generate the Affleck-Kennedy-Lieb-Tasaki ground state, a further resource for quantum computation. We justify, and derive analytic results for, an effective charge-spin Hamiltonian which is valid over a wide range of parameters and agrees well with exact numerical results of a realistic effective-mass model. Our analysis also indicates that the method is robust to the choice of dot-size and initialization errors, as well as decoherence. PMID:20868084

  13. Spin Filtering and Entanglement Swapping through Coherent Evolution of a Single Quantum Dot

    E-print Network

    Jose Garcia Coello; Abolfazl Bayat; Sougato Bose; John H. Jefferson; Charles E. Creffield

    2010-08-18

    We exploit the non-dissipative dynamics of a pair of electrons in a large square quantum dot to perform singlet-triplet spin measurement through a single charge detection and show how this may be used for entanglement swapping and teleportation. The method is also used to generate the AKLT ground state, a further resource for quantum computation. We justify, and derive analytic results for, an effective charge-spin Hamiltonian which is valid over a wide range of parameters and agrees well with exact numerical results of a realistic effective-mass model. Our analysis also indicates that the method is robust to choice of dot-size and initialization errors, as well as decoherence introduced by the hyperfine interaction.

  14. Transverse target single-spin asymmetry in inclusive electroproduction of charged pions and kaons

    NASA Astrophysics Data System (ADS)

    Airapetian, A.; Akopov, N.; Akopov, Z.; Aschenauer, E. C.; Augustyniak, W.; Avakian, R.; Avetissian, A.; Avetisyan, E.; Belostotski, S.; Bianchi, N.; Blok, H. P.; Borissov, A.; Bowles, J.; Bryzgalov, V.; Burns, J.; Capiluppi, M.; Capitani, G. P.; Cisbani, E.; Ciullo, G.; Contalbrigo, M.; Dalpiaz, P. F.; Deconinck, W.; De Leo, R.; De Nardo, L.; De Sanctis, E.; Diefenthaler, M.; Di Nezza, P.; Düren, M.; Ehrenfried, M.; Elbakian, G.; Ellinghaus, F.; Fabbri, R.; Fantoni, A.; Felawka, L.; Frullani, S.; Gabbert, D.; Gapienko, G.; Gapienko, V.; Gavrilov, G.; Gharibyan, V.; Giordano, F.; Gliske, S.; Golembiovskaya, M.; Hadjidakis, C.; Hartig, M.; Hasch, D.; Hillenbrand, A.; Hoek, M.; Holler, Y.; Hristova, I.; Ivanilov, A.; Jackson, H. E.; Joosten, S.; Kaiser, R.; Karyan, G.; Keri, T.; Kinney, E.; Kisselev, A.; Korotkov, V.; Kozlov, V.; Kravchenko, P.; Krivokhijine, V. G.; Lagamba, L.; Lapikás, L.; Lehmann, I.; Lenisa, P.; López Ruiz, A.; Lorenzon, W.; Ma, B.-Q.; Mahon, D.; Makins, N. C. R.; Manaenkov, S. I.; Mao, Y.; Marianski, B.; Martínez de la Ossa, A.; Marukyan, H.; Miller, C. A.; Miyachi, Y.; Movsisyan, A.; Murray, M.; Mussgiller, A.; Nappi, E.; Naryshkin, Y.; Negodaev, M.; Nowak, W.-D.; Pappalardo, L. L.; Perez-Benito, R.; Petrosyan, A.; Raithel, M.; Reimer, P. E.; Reolon, A. R.; Riedl, C.; Rith, K.; Rosner, G.; Rostomyan, A.; Rubin, J.; Ryckbosch, D.; Salomatin, Y.; Sanftl, F.; Schäfer, A.; Schnell, G.; Seitz, B.; Shibata, T.-A.; Shutov, V.; Stancari, M.; Statera, M.; Steffens, E.; Steijger, J. J. M.; Stewart, J.; Stinzing, F.; Taroian, S.; Terkulov, A.; Truty, R.; Trzcinski, A.; Tytgat, M.; Van Haarlem, Y.; Van Hulse, C.; Veretennikov, D.; Vikhrov, V.; Vilardi, I.; Wang, S.; Yaschenko, S.; Ye, Z.; Yen, S.; Yu, W.; Zagrebelnyy, V.; Zeiler, D.; Zihlmann, B.; Zupranski, P.

    2014-01-01

    Single-spin asymmetries were investigated in inclusive electroproduction of charged pions and kaons from transversely polarized protons at the HERMES experiment. The asymmetries were studied as a function of the azimuthal angle ? about the beam direction between the target-spin direction and the hadron production plane, the transverse hadron momentum PT relative to the direction of the incident beam, and the Feynman variable xF. The sin ? amplitudes are positive for ?+ and K+, slightly negative for ?- and consistent with zero for K-, with particular PT but weak xF dependences. Especially large asymmetries are observed for two small subsamples of events, where also the scattered electron was recorded by the spectrometer.

  15. Physical properties of the lipid bilayer membrane made of cortical and nuclear bovine lens lipids: EPR spin-labeling studies

    PubMed Central

    Raguz, Marija; Widomska, Justyna; Dillon, James; Gaillard, Elizabeth R.; Subczynski, Witold K.

    2009-01-01

    The physical properties of membranes derived from the total lipids extracted from the lens cortex and nucleus of a two-year-old cow were investigated using EPR spin labeling methods. Conventional EPR spectra and saturation-recovery curves show that spin labels detect a single homogenous environment in membranes made from cortical lipids. Properties of these membranes are very similar to those reported by us for membranes made of the total lipid extract of six-month-old calf lenses (J. Widomska, M. Raguz, J. Dillon, E. R. Gaillard, W. K. Subczynski, Biochim. Biophys. Acta 1768 (2007) 1454–1465). However, in membranes made from nuclear lipids, two domains were detected by the EPR discrimination by oxygen transport method using the cholesterol analogue spin label and were assigned to the bulk phospholipid-cholesterol domain (PCD) and the immiscible cholesterol crystalline domain (CCD), respectively. Profiles of the order parameter, hydrophobicity, and the oxygen transport parameter are practically identical in the bulk PCD when measured for either the cortical or nuclear lipid membranes. In both membranes, lipids in the bulk PCD are strongly immobilized at all depths. Hydrophobicity and oxygen transport parameter profiles have a rectangular shape with an abrupt change between the C9 and C10 positions, which is approximately where the steroid-ring structure of cholesterol reaches into the membrane. The permeability coefficient for oxygen, estimated at 35°C, across the bulk PCD in both membranes is slightly lower than across the water layer of the same thickness. However, the evaluated upper limit of the permeability coefficient for oxygen across the CCD (34.4 cm/s) is significantly lower than across the water layer of the same thickness (85.9 cm/s), indicating that the CCD can significantly reduce oxygen transport in the lens nucleus. PMID:19761756

  16. Electron-nuclear spin coupling in nano-scale devices: self-sustaining resistance oscillations and controlled multiple quantum coherences

    NASA Astrophysics Data System (ADS)

    Yusa, Go

    2005-03-01

    Author: G Yusa, K. Muraki, K. Takashina (NTT BRL), K. Hashimoto (SORST-JST), and Y. Hirayama (NTT BRL and SORST-JST). We studied electron-nuclear spin coupled systems implemented in microscopic fractional quantum Hall devices and found that in a constant voltage measurement, the longitudinal resistance of such devices oscillates self-sustainingly with a period of about 200 sec. Such behavior suggests that the average nuclear spin polarization self-sustainingly oscillates between randomized and polarized states. When the resistance is measured in constant current mode, on the other hand, nuclear spins are polarized and reach a steady state in about 200 sec. Using the polarized state as an initial state, quantum mechanical superpositional states between four nuclear spin states (multiple quantum coherence) are controlled by pulsed radio frequency radiation resonant with nuclear spin transitions (nuclear magnetic resonance, NMR). Any arbitrary multiple quantum coherent state can be detected as change in the longitudinal resistance. Our findings represent a big step closer to practical all-electrical solid state nuclear spin quantum computing and quantum memory devices.

  17. Nuclear level density parameter: its dependence on spin and temperature

    SciTech Connect

    Rajasekaran, M.; Rajasekaran, T.R.; Arunachalam, N.

    1988-01-01

    The effect of temperature and angular momentum on the nuclear level density parameter is investigated. Pairing correlations and deformation degrees of freedom are also included. The level density parameter fluctuates at low temperatures and the effect of angular momentum is very pronounced at low temperatures. The variation of shell correction with angular momentum is also studied. Results for the nuclei /sub //sub <1/ /sub 66//sup 58/Dy, /sub //sub <1/ /sub 78//sup 94/Pt, and /sub //sub <1/ /sub 70//sup 70/Yb are presented.

  18. Spin-dipole strength functions of 4He with realistic nuclear forces

    NASA Astrophysics Data System (ADS)

    Horiuchi, W.; Suzuki, Y.

    2013-03-01

    Both isoscalar and isovector spin-dipole excitations of 4He are studied using realistic nuclear forces in the complex scaling method. The ground state of 4He and discretized continuum states with J?=0-,1-,2- for A=4 nuclei are described in explicitly correlated Gaussians reinforced with global vectors for angular motion. Two- and three-body decay channels are specifically treated to take into account final state interactions. The observed resonance energies and widths of the negative-parity levels are all in fair agreement with those calculated from both the spin-dipole and electric-dipole strength functions as well as the energy eigenvalues of the complex scaled Hamiltonian. Spin-dipole sum rules, both non-energy-weighted and energy-weighted, are discussed in relation to tensor correlations in the ground state of 4He.

  19. Entanglement of systems of dipolar coupled nuclear spins at the adiabatic demagnetization

    NASA Astrophysics Data System (ADS)

    Doronin, S. I.; Fel'dman, E. B.; Kucherov, M. M.; Pyrkov, A. N.

    2009-01-01

    We consider the adiabatic demagnetization in the rotating reference frame (ADRF) of a system of dipolar coupled nuclear spins s = 1/2 in an external magnetic field. The demagnetization starts with the offset of the external magnetic field (in frequency units) from the Larmor frequency being several times greater than the local dipolar field. For different subsystem sizes, we have found from numerical simulations the temperatures at which subsystems of a one-dimensional nine-spin chain and a plane nine-spin cluster become entangled. These temperatures are of the order of microkelvins and are almost independent of the subsystem size. There is a weak dependence of the temperature on the space dimension of the system.

  20. Entanglement of systems of dipolar coupled nuclear spins at the adiabatic demagnetization.

    PubMed

    Doronin, S I; Fel'dman, E B; Kucherov, M M; Pyrkov, A N

    2009-01-14

    We consider the adiabatic demagnetization in the rotating reference frame (ADRF) of a system of dipolar coupled nuclear spins s = 1/2 in an external magnetic field. The demagnetization starts with the offset of the external magnetic field (in frequency units) from the Larmor frequency being several times greater than the local dipolar field. For different subsystem sizes, we have found from numerical simulations the temperatures at which subsystems of a one-dimensional nine-spin chain and a plane nine-spin cluster become entangled. These temperatures are of the order of microkelvins and are almost independent of the subsystem size. There is a weak dependence of the temperature on the space dimension of the system. PMID:21813986

  1. Spin-tunnel investigation of the spinning characteristics of typical single-engine general aviation airplane designs. 2: Low-wing model A; tail parachute diameter and canopy distance for emergency spin recovery

    NASA Technical Reports Server (NTRS)

    Burk, S. M., Jr.; Bowman, J. S., Jr.; White, W. L.

    1977-01-01

    A spin tunnel study is reported on a scale model of a research airplane typical of low-wing, single-engine, light general aviation airplanes to determine the tail parachute diameter and canopy distance (riser length plus suspension-line length) required for energency spin recovery. Nine tail configurations were tested, resulting in a wide range of developed spin conditions, including steep spins and flat spins. The results indicate that the full-scale parachute diameter required for satisfactory recovery from the most critical conditions investigated is about 3.2 m and that the canopy distance, which was found to be critical for flat spins, should be between 4.6 and 6.1 m.

  2. High-pressure Magic Angle Spinning Nuclear Magnetic Resonance

    SciTech Connect

    Hoyt, David W.; Turcu, Romulus VF; Sears, Jesse A.; Rosso, Kevin M.; Burton, Sarah D.; Felmy, Andrew R.; Hu, Jian Z.

    2011-10-01

    A high-pressure magic angle spinning (MAS) NMR capability, consisting of a reusable high-pressure MAS rotor, a high-pressure loading/reaction chamber for in situ sealing and re-opening of the high-pressure MAS rotor, and a MAS probe with a localized RF coil for background signal suppression, is reported. The unusual technical challenges associated with development of a reusable high-pressure MAS rotor are addressed in part by modifying standard ceramics for the rotor sleeve to include micro-groves at the internal surface at both ends of the cylinder. In this way, not only is the advantage of ceramic cylinders for withstanding very high-pressure utilized, but also plastic bushings can be glued tightly in place so that other plastic sealing mechanisms/components and O-rings can be mounted to create the desired high-pressure seal. Using this strategy, sealed internal pressures exceeding 150 bars have been achieved and sustained under ambient external pressure with minimal penetration loss of pressure for 72 hours. As an application example, in situ 13C MAS NMR studies of mineral carbonation reaction intermediates and final products of forsterite (Mg2SiO4) reacted with supercritical CO2 and H2O at 150 bar and 50?C are reported, with relevance to geological sequestration of carbon dioxide.

  3. High-pressure magic angle spinning nuclear magnetic resonance.

    PubMed

    Hoyt, David W; Turcu, Romulus V F; Sears, Jesse A; Rosso, Kevin M; Burton, Sarah D; Felmy, Andrew R; Hu, Jian Zhi

    2011-10-01

    A high-pressure magic angle spinning (MAS) NMR capability, consisting of a reusable high-pressure MAS rotor, a high-pressure rotor loading/reaction chamber for in situ sealing and re-opening of the high-pressure MAS rotor, and a MAS probe with a localized RF coil for background signal suppression, is reported. The unusual technical challenges associated with development of a reusable high-pressure MAS rotor are addressed in part by modifying standard ceramics for the rotor sleeve by abrading the internal surface at both ends of the cylinder. In this way, not only is the advantage of ceramic cylinders for withstanding very high-pressure utilized, but also plastic bushings can be glued tightly in place so that other removable plastic sealing mechanisms/components and O-rings can be mounted to create the desired high-pressure seal. Using this strategy, sealed internal pressures exceeding 150 bars have been achieved and sustained under ambient external pressure with minimal loss of pressure for 72 h. As an application example, in situ(13)C MAS NMR studies of mineral carbonation reaction intermediates and final products of forsterite (Mg(2)SiO(4)) reacted with supercritical CO(2) and H(2)O at 150 bar and 50°C are reported, with relevance to geological sequestration of carbon dioxide. PMID:21862372

  4. Optical and Nuclear Spin Spectroscopy in PRASEODYMIUM(3+):LANTHANUM Fluoride by Optical Pumping

    NASA Astrophysics Data System (ADS)

    Wald, Lawrence Leroy

    A Stark Modulated Optical Pumping (SMOP) technique was used as a sensitive probe of optical hole-burning to study the effects of nuclear spin interactions in Pr ^{3+}:LaF_3. The results of two experiments are reported. In the first experiment, the SMOP technique is applied for optical detection of the NQR spectrum of the Pr^{3+} optical ground state. Frequency and linewidth variations of the Pr ^{3+} ground state hyperfine levels for different positions within the main ^3 H_4(Gamma1) -^1D_2(Gamma 1) inhomogeneous optical line and satellite transitions of Pr^{3+}:LaF _3 are observed. A linear increase in the broadening of the Pr^{3+} hyperfine transitions, without a shift of central frequency, is measured as the laser is tuned toward the wings of the inhomogeneous optical transition. The linear variation is attributed to electric quadrupole broadening caused by changes in local density of point defects across the Stark broadened optical transition. The optically detected NQR spectra of the satellite transitions associated with Pr ion pairs are shifted in frequency, and for most satellites are narrower in width than the NQR spectra found in the wings of the main inhomogeneous optical line. In the second experiment, direct evidence for the presence of a spin diffusion barrier or "frozen core" in Pr^{3+}:LaF _3 is observed by examining the cross relaxation between the Pr and F nuclei in a magnetic field chosen so that a pair of the optical ground state Pr^ {3+} hyperfine energy levels matches the F splitting or a multiple of the F splitting. This level crossing condition allows resonant flip-flop interactions with the nearest neighbor frozen core fluorine spins to re-populate Pr^{3+} hyperfine levels emptied by laser hole-burning, and is detected as enhanced absorption of the laser beam. The coupling of core fluorine spins to bulk fluorine spins during Pr-F cross-relaxation is measured by NMR of the bulk fluorine spin magnetization. The rate of cross relaxation between the Pr spins and the bulk F spins measured in this way is at least three to four orders of magnitude slower than that expected in the absence of a spin diffusion barrier. This reduction of coupling indicates nearly complete de-tuning of the frozen core F spins immediately surrounding the Pr^{3+} ion, cutting off resonant coupling with the bulk F spins.

  5. Diamond as a Solid State Quantum Computer with a Linear Chain of Nuclear Spins System

    NASA Astrophysics Data System (ADS)

    López, G. V.; López, G. V.

    By removing a $^{12}C$ atom from the tetrahedral configuration of the diamond, replace it by a $^{13}C$ atom, and repeating this in a linear direction, it is possible to have a linear chain of nuclear spins one half and to build a solid state quantum computer. One qubit rotation and controlled-not (CNOT) quantum gates are obtained immediately from this configuration, and CNOT quantum gate is used to determined the design parameters of this quantum computer.

  6. Discrimination of nuclear spin isomers exploiting the excited state dynamics of a quinodimethane derivative

    SciTech Connect

    Obaid, Rana [Institut für Theoretische Chemie, Universität Wien, Währinger Str. 17, 1090 Wien (Austria); Faculty of Pharmacy, Al-Quds University, Abu Dis, Palestine (Country Unknown); Kinzel, Daniel; Oppel, Markus, E-mail: markus.oppel@univie.ac.at; González, Leticia [Institut für Theoretische Chemie, Universität Wien, Währinger Str. 17, 1090 Wien (Austria)

    2014-10-28

    Despite the concept of nuclear spin isomers (NSIs) exists since the early days of quantum mechanics, only few approaches have been suggested to separate different NSIs. Here, a method is proposed to discriminate different NSIs of a quinodimethane derivative using its electronic excited state dynamics. After electronic excitation by a laser field with femtosecond time duration, a difference in the behavior of several quantum mechanical operators can be observed. A pump-probe experimental approach for separating these different NSIs is then proposed.

  7. Exploiting Spin Echo Decay in the Detection of Nuclear Quadrupole Resonance Signals

    Microsoft Academic Search

    Samuel D. Somasundaram; Andreas Jakobsson; John A. S. Smith; Kaspar Althoefer

    2007-01-01

    Nuclear quadrupole resonance (NQR) is a radio-frequency technique that can be used to detect the presence of quadrupolar nuclei, such as the 14N nucleus prevalent in many explosives and narcotics. In a typical application, one observes trains of decaying NQR echoes, in which the decay is governed by the spin echo decay time(s) of the resonant line(s). In most detection

  8. Optical measurements of methyl-group tunneling and nuclear-spin conversion

    NASA Astrophysics Data System (ADS)

    von Borczyskowski, Christian; Oppenländer, Andreas; Trommsdorff, H. Peter; Vial, Jean-Claude

    1990-12-01

    We report a novel approach to measure rotational tunneling in condensed phases. High-resolution optical spectroscopic methods are used to unravel the tunneling level structure and to measure the rate of the nuclear-spin conversion. The method is demonstrated in experiments on the rotational motion of methyl groups in a crystal of durene doped with di-methyl-s-tetrazine but it can readily be transposed to other tunneling systems.

  9. Magnetic order in nuclear spin two-dimensional lattices due to electronelectron interactions

    E-print Network

    Braunecker, Bernd

    in a quantum dot. The interaction Hamiltonian can be written in the form Hdot hyp ¼ X i AiS Á Ii ¼ X i Ai½Sz Iz introduced S7 ¼ Sx 7iSy , I7 i ¼ Ix i 7Iy i , and Ai % AjcðriÞj2 with A a proportionality constant and cðriÞ the wave function of the confined electron on the quantum dot. The number of nuclear spins is large

  10. Propeller swirl effect on single-engine general-aviation aircraft stall-spin tendencies

    NASA Technical Reports Server (NTRS)

    Katz, Joseph; Feistel, Terry W.

    1987-01-01

    An investigation is conducted of the effect of a single engine, untapered low wing general aviation aircraft propeller's swirl on the craft's stall pattern. The asymmetrical character of the propeller's swirl can trigger an early stall of one of the wings, aggravating the spin-entry condition. It is shown that the combination of this propeller-induced effect with adverse sideslip can result in large and abrupt changes in the rolling moment, in such conditions as uncoordinated low speed turning maneuvers where the pilot yaws the aircraft with wings level, rather than rolling it.

  11. Dual-channel lock-in magnetometer with a single spin in diamond

    E-print Network

    N. M. Nusran; M. V. Gurudev Dutt

    2014-07-02

    We present an experimental method to perform dual-channel lock-in magnetometry of time-dependent magnetic fields using a single spin associated with a nitrogen-vacancy (NV) color center in diamond. We incorporate multi-pulse quantum sensing sequences with phase estimation algorithms to achieve linearized field readout and constant, nearly decoherence-limited sensitivity over a wide dynamic range. Furthermore, we demonstrate unambiguous reconstruction of the amplitude and phase of the magnetic field. We show that our technique can be applied to measure random phase jumps in the magnetic field, as well as phase-sensitive readout of the frequency.

  12. Trigluon correlations and single transverse spin asymmetry in open charm production

    SciTech Connect

    Kang Zhongbo; Qiu Jianwei [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States)

    2009-08-04

    We study the single transverse-spin asymmetry for open charm production in the semiinclusive lepton-hadron deep inelastic scattering (SIDIS) and pp collision. Within collinear factorization approach, we find that the asymmetry is sensitive to the twist-3 trigluon correlation functions in the proton. With a simple model for the trigluon correlation functions, we estimate the asymmetry in SIDIS for both COMPASS and eRHIC kinematics, as well as in pp collision at RHIC energy. We discuss the possibilities of extracting the trigluon correlation functions in these experiments.

  13. Generating Entangled Spin States for Quantum Metrology by Single-Photon Detection

    E-print Network

    McConnell, Robert; ?uk, Senka; Hu, Jiazhong; Schleier-Smith, Monika H; Vuleti?, Vladan

    2013-01-01

    We propose and analyze a probabilistic but heralded scheme to generate pure, entangled, non-Gaussian states of collective spin in large atomic ensembles by means of single-photon detection. One photon announces the preparation of a Dicke state, while two or more photons announce Schr\\"odinger cat states. The method produces pure states even for finite photon detection efficiency and weak atom-photon coupling. The entanglement generation can be made quasi-deterministic by means of repeated trial and feedback, enabling metrology beyond the standard quantum limit.

  14. Generating entangled spin states for quantum metrology by single-photon detection

    NASA Astrophysics Data System (ADS)

    McConnell, Robert; Zhang, Hao; ?uk, Senka; Hu, Jiazhong; Schleier-Smith, Monika H.; Vuleti?, Vladan

    2013-12-01

    We propose and analyze a probabilistic but heralded scheme to generate pure, entangled, non-Gaussian states of collective spin in large atomic ensembles by means of single-photon detection. One photon announces the preparation of a Dicke state, while two or more photons announce Schrödinger cat states. The method produces pure states even for finite photon detection efficiency and weak atom-photon coupling. The entanglement generation can be made quasideterministic by means of repeated trial and feedback, enabling metrology beyond the standard quantum limit.

  15. Single-spin azimuthal asymmetry in exclusive electroproduction of ?+ mesons on transversely polarized protons

    NASA Astrophysics Data System (ADS)

    Airapetian, A.; Akopov, N.; Akopov, Z.; Aschenauer, E. C.; Augustyniak, W.; Avetissian, A.; Avetisyan, E.; Ball, B.; Belostotski, S.; Bianchi, N.; Blok, H. P.; Böttcher, H.; Bonomo, C.; Borissov, A.; Bryzgalov, V.; Burns, J.; Capiluppi, M.; Capitani, G. P.; Cisbani, E.; Ciullo, G.; Contalbrigo, M.; Dalpiaz, P. F.; Deconinck, W.; de Leo, R.; de Nardo, L.; de Sanctis, E.; Diefenthaler, M.; di Nezza, P.; Dreschler, J.; Düren, M.; Ehrenfried, M.; Elbakian, G.; Ellinghaus, F.; Fabbri, R.; Fantoni, A.; Felawka, L.; Frullani, S.; Gabbert, D.; Gapienko, V.; Garibaldi, F.; Gharibyan, V.; Giordano, F.; Gliske, S.; Hadjidakis, C.; Hartig, M.; Hasch, D.; Hill, G.; Hillenbrand, A.; Hoek, M.; Holler, Y.; Hristova, I.; Imazu, Y.; Ivanilov, A.; Jackson, H. E.; Jo, H. S.; Joosten, S.; Kaiser, R.; Keri, T.; Kinney, E.; Kisselev, A.; Kobayashi, N.; Korotkov, V.; Kravchenko, P.; Lagamba, L.; Lamb, R.; Lapikás, L.; Lehmann, I.; Lenisa, P.; Linden-Levy, L. A.; López Ruiz, A.; Lorenzon, W.; Lu, X.-G.; Lu, X.-R.; Ma, B.-Q.; Mahon, D.; Makins, N. C. R.; Manaenkov, S. I.; Manfré, L.; Mao, Y.; Marianski, B.; Martinez de La Ossa, B.; Marukyan, H.; Miller, C. A.; Miyachi, Y.; Movsisyan, A.; Muccifora, V.; Murray, M.; Mussgiller, A.; Nappi, E.; Naryshkin, Y.; Nass, A.; Nowak, W.-D.; Pappalardo, L. L.; Perez-Benito, R.; Reimer, P. E.; Reolon, A. R.; Riedl, C.; Rith, K.; Rosner, G.; Rostomyan, A.; Rubin, J.; Ryckbosch, D.; Salomatin, Y.; Sanftl, F.; Schäfer, A.; Schnell, G.; Schüler, K. P.; Seitz, B.; Shibata, T.-A.; Shutov, V.; Stancari, M.; Statera, M.; Steijger, J. J. M.; Stenzel, H.; Stewart, J.; Taroian, S.; Terkulov, A.; Trzcinski, A.; Tytgat, M.; Vandenbroucke, A.; van der Nat, P. B.; van Haarlem, Y.; van Hulse, C.; Varanda, M.; Veretennikov, D.; Vikhrov, V.; Vilardi, I.; Vogel, C.; Wang, S.; Yaschenko, S.; Ye, H.; Ye, Z.; Yen, S.; Yu, W.; Zeiler, D.; Zihlmann, B.; Zupranski, P.; HERMES Collaboration

    2010-01-01

    Exclusive electroproduction of ? mesons was studied by scattering 27.6 GeV positrons or electrons off a transversely polarized hydrogen target. The single-spin azimuthal asymmetry with respect to target polarization was measured as a function of the Mandelstam variable t, the Bjorken scaling variable xB, and the virtuality Q of the exchanged photon. The extracted Fourier components of the asymmetry were found to be consistent with zero, except one that was found to be large and that involves interference of contributions from longitudinal and transverse virtual photons.

  16. Generating Entangled Spin States for Quantum Metrology by Single-Photon Detection

    NASA Astrophysics Data System (ADS)

    McConnell, Robert; Zhang, Hao; Cuk, Senka; Hu, Jiazhong; Schleier-Smith, Monika; Vuletic, Vladan

    2014-05-01

    We present a proposal and latest experimental results on a probabilistic but heralded scheme to generate non-Gaussian entangled states of collective spin in large atomic ensembles by means of single-photon detection. One photon announces the preparation of a Dicke state, while two or more photons announce Schrödinger cat states. The entangled states thus produced allow interferometry below the Standard Quantum Limit (SQL). The method produces nearly pure states even for finite photon detection efficiency and weak atom-photon coupling. The entanglement generation can be made quasi-deterministic by means of repeated trial and feedback.

  17. Cytoplasmic Solvent Structure of Single Barnacle Muscle Cells Studied by Electron Spin Resonance

    PubMed Central

    Sachs, Fred; Latorre, Ramon

    1974-01-01

    A free radical probe was introduced into single barnacle muscle cells, and its freedom of motion inferred from the spin resonance spectra. The probe reported an average local viscosity of 5-10 cp compared with 1 cp for pure water. From a comparison of the temperature dependence of the probe's tumbling rate in model aqueous systems and in the muscle we concluded that in the muscle the probe was undergoing fast exchange between sites of different mobility. Thus 10 cp must be taken as an upper limit for the viscosity of most cell water. PMID:4364470

  18. Optical pumping and population transfer of nuclear-spin states of caesium atoms in high magnetic fields

    Microsoft Academic Search

    Jun Luo; Xian-Ping Sun; Xi-Zhi Zeng; Ming-Sheng Zhan

    2007-01-01

    Nuclear-spin states of gaseous-state Cs atoms in the ground state are optically manipulated using a Ti:sapphire laser in a magnetic field of 1.516 T, in which optical coupling of the nuclear-spin states is achieved through hyperfine interactions between electrons and nuclei. The steady-state population distribution in the hyperfine Zeeman sublevels of the ground state is detected by using a tunable

  19. Analytic derivative couplings for spin-flip configuration interaction singles and spin-flip time-dependent density functional theory.

    PubMed

    Zhang, Xing; Herbert, John M

    2014-08-14

    We revisit the calculation of analytic derivative couplings for configuration interaction singles (CIS), and derive and implement these couplings for its spin-flip variant for the first time. Our algorithm is closely related to the CIS analytic energy gradient algorithm and should be straightforward to implement in any quantum chemistry code that has CIS analytic energy gradients. The additional cost of evaluating the derivative couplings is small in comparison to the cost of evaluating the gradients for the two electronic states in question. Incorporation of an exchange-correlation term provides an ad hoc extension of this formalism to time-dependent density functional theory within the Tamm-Dancoff approximation, without the need to invoke quadratic response theory or evaluate third derivatives of the exchange-correlation functional. Application to several different conical intersections in ethylene demonstrates that minimum-energy crossing points along conical seams can be located at substantially reduced cost when analytic derivative couplings are employed, as compared to use of a branching-plane updating algorithm that does not require these couplings. Application to H3 near its D(3h) geometry demonstrates that correct topology is obtained in the vicinity of a conical intersection involving a degenerate ground state. PMID:25134548

  20. Magic angle spinning NMR of proteins: high-frequency dynamic nuclear polarization and (1)h detection.

    PubMed

    Su, Yongchao; Andreas, Loren; Griffin, Robert G

    2015-06-01

    Magic angle spinning (MAS) NMR studies of amyloid and membrane proteins and large macromolecular complexes are an important new approach to structural biology. However, the applicability of these experiments, which are based on (13)C- and (15)N-detected spectra, would be enhanced if the sensitivity were improved. Here we discuss two advances that address this problem: high-frequency dynamic nuclear polarization (DNP) and (1)H-detected MAS techniques. DNP is a sensitivity enhancement technique that transfers the high polarization of exogenous unpaired electrons to nuclear spins via microwave irradiation of electron-nuclear transitions. DNP boosts NMR signal intensities by factors of 10(2) to 10(3), thereby overcoming NMR's inherent low sensitivity. Alternatively, it permits structural investigations at the nanomolar scale. In addition, (1)H detection is feasible primarily because of the development of MAS rotors that spin at frequencies of 40 to 60 kHz or higher and the preparation of extensively (2)H-labeled proteins. PMID:25839340

  1. {sigma}-nuclear spin-orbit coupling from two-pion exchange

    SciTech Connect

    Kaiser, N. [Physik-Department T39, Technische Universitaet Muenchen, D-85747 Garching (Germany)

    2007-12-15

    Using SU(3) chiral perturbation theory we calculate the density-dependent complex-valued spin-orbit coupling strength U{sub {sigma}}{sub ls}(k{sub f})+iW{sub {sigma}}{sub ls}(k{sub f}) of a {sigma} hyperon in the nuclear medium. The leading long-range {sigma}N interaction arises from iterated one-pion exchange with a {lambda} or a {sigma} hyperon in the intermediate state. We find from this unique long-range dynamics a sizable ''wrong-sign'' spin-orbit coupling strength of U{sub {sigma}}{sub ls}(k{sub f0}){approx_equal}-20 MeV fm{sup 2} at normal nuclear matter density {rho}{sub 0}=0.16 fm{sup -3}. The strong {sigma}N{yields}{lambda}N conversion process contributes at the same time an imaginary part of W{sub {sigma}}{sub ls}(k{sub f0}){approx_equal}-12 MeV fm{sup 2}. When combined with estimates of the short-range contribution the total {sigma}-nuclear spin-orbit coupling becomes rather weak.

  2. Spin-Wave Spectrum in ``Single-Domain'' Magnetic Ground State of Triangular Lattice Antiferromagnet CuFeO2

    NASA Astrophysics Data System (ADS)

    Nakajima, Taro; Mitsuda, Setsuo; Haku, Tendai; Shibata, Kohei; Yoshitomi, Keisuke; Noda, Yukio; Aso, Naofumi; Uwatoko, Yoshiya; Terada, Noriki

    2011-01-01

    By means of neutron scattering measurements, we have investigated spin-wave excitation in a collinear four-sublattice (4SL) magnetic ground state of a triangular lattice antiferromagnet CuFeO2, which has been of recent interest as a strongly frustrated magnet, a spin--lattice coupled system and a multiferroic. To avoid mixing of spin-wave spectrum from magnetic domains having three different orientations reflecting trigonal symmetry of the crystal structure, we have applied uniaxial pressure on [1\\bar{1}0] direction of a single crystal CuFeO2. By elastic neutron scattering measurements, we have found that only 10 MPa of the uniaxial pressure results in almost ``single domain'' state in the 4SL phase. We have thus performed inelastic neutron scattering measurements using the single domain sample, and have identified two distinct spin-wave branches. The dispersion relation of the upper spin-wave branch cannot be explained by the previous theoretical model [R. S. Fishman: J. Appl. Phys. 103 (2008) 07B109]. This implies the importance of the lattice degree of freedom in the spin-wave excitation in this system, because the previous calculation neglected the effect of the spin-driven lattice distortion in the 4SL phase. We have also discussed relationship between the present results and the recently discovered ``electromagnon'' excitation.

  3. Single-shot nuclear magnetization recovery curves with force-gradient detection

    PubMed Central

    Alexson, Dimitri A.; Hickman, Steven A.; Marohn, John A.; Smith, Doran D.

    2012-01-01

    We measure the spin-lattice relaxation time as a function of sample temperature in GaAs in a real-time single-shot inversion recovery experiment using spin force gradients acting on a magnetic tipped cantilever. After inverting 69Ga spins localized near the magnet with a single 20?ms adiabatic rapid passage sweep, the spins’ magnetization recovery was passively tracked by recording the cantilever’s frequency change, which is proportional to the longitudinal component of the spins’ magnetization. The cantilever’s frequency was recorded for a time 3*T1 for sample temperatures ranging from 4.8 to 25?K. The temperature dependence was observed for the 69Ga quadrupolar relaxation interaction.

  4. Universal quantum gates on electron-spin qubits with quantum dots inside single-side optical microcavities

    E-print Network

    Hai-Rui Wei; Fu-Guo Deng

    2015-03-01

    We present some compact quantum circuits for a deterministic quantum computing on electron-spin qubits assisted by quantum dots inside single-side optical microcavities, including the CNOT, Toffoli, and Fredkin gates. They are constructed by exploiting the giant optical Faraday rotation induced by a single-electron spin in a quantum dot inside a single-side optical microcavity as a result of cavity quantum electrodynamics. Our universal quantum gates have some advantages. First, all the gates are accomplished with a success probability of 100% in principle. Second, our schemes require no additional electron-spin qubits and they are achieved by some input-output processes of a single photon. Third, our circuits for these gates are simple and economic. Moreover, our devices for these gates work in both the weak coupling and the strong coupling regimes, and they are feasible in experiment.

  5. Probing Johnson noise and ballistic transport in normal metals with a single-spin qubit

    NASA Astrophysics Data System (ADS)

    Kolkowitz, S.; Safira, A.; High, A. A.; Devlin, R. C.; Choi, S.; Unterreithmeier, Q. P.; Patterson, D.; Zibrov, A. S.; Manucharyan, V. E.; Park, H.; Lukin, M. D.

    2015-03-01

    Thermally induced electrical currents, known as Johnson noise, cause fluctuating electric and magnetic fields in proximity to a conductor. These fluctuations are intrinsically related to the conductivity of the metal. We use single-spin qubits associated with nitrogen-vacancy centers in diamond to probe Johnson noise in the vicinity of conductive silver films. Measurements of polycrystalline silver films over a range of distances (20 to 200 nanometers) and temperatures (10 to 300 kelvin) are consistent with the classically expected behavior of the magnetic fluctuations. However, we find that Johnson noise is markedly suppressed next to single-crystal films, indicative of a substantial deviation from Ohm’s law at length scales below the electron mean free path. Our results are consistent with a generalized model that accounts for the ballistic motion of electrons in the metal, indicating that under the appropriate conditions, nearby electrodes may be used for controlling nanoscale optoelectronic, atomic, and solid-state quantum systems.

  6. PHYSICS OF ELEMENTARY PARTICLES AND FIELDS: Single Transverse Spin Asymmetries at Parton Level

    NASA Astrophysics Data System (ADS)

    Cao, Hui-Geng; Ma, Jian-Ping; Sang, Hua-Zheng

    2010-02-01

    Two factorization approaches have been proposed for single transverse spin asymmetries. One is the collinear factorization, the other is the transverse-momentum-dependent factorization. They have been previously derived in a formal way by using diagram expansion at hadron level. If the two factorizations hold or can be proven, they should also hold when we replace hadrons with parton states. We examine these two factorizations at parton level with massless partons. It is nontrivial to generate these asymmetries at parton level with massless partons because the asymmetries require helicity-flip and nonzero absorptive parts in scattering amplitudes. By constructing suitable parton states with massless partons we derive the two factorizations for the asymmetry in Drell-Yan processes. It is found from our results that the collinear factorization derived at parton level is not the same as that derived at hadron level. Our results with massless partons confirm those derived with single massive parton state in our previous works.

  7. Quantum measurement of a mesoscopic spin ensemble

    SciTech Connect

    Giedke, G. [Institut fuer Quantenelektronik, ETH Zuerich, Wolfgang-Pauli-Strasse 16, 8093 Zurich (Switzerland); Max-Planck-Institut fuer Quantenoptik, H.-Kopfermann-Str., 85748 Garching (Germany); Taylor, J. M.; Lukin, M. D. [Department of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States); D'Alessandro, D. [Department of Mathematics, Iowa State University, Ames, Iowa 50011 (United States); Imamoglu, A. [Institut fuer Quantenelektronik, ETH Zuerich, Wolfgang-Pauli-Strasse 16, 8093 Zurich (Switzerland)

    2006-09-15

    We describe a method for precise estimation of the polarization of a mesoscopic spin ensemble by using its coupling to a single two-level system. Our approach requires a minimal number of measurements on the two-level system for a given measurement precision. We consider the application of this method to the case of nuclear-spin ensemble defined by a single electron-charged quantum dot: we show that decreasing the electron spin dephasing due to nuclei and increasing the fidelity of nuclear-spin-based quantum memory could be within the reach of present day experiments.

  8. Nuclear spin dependence of hydrogenic plasmas in the laboratory and the diffuse interstellar medium

    NASA Astrophysics Data System (ADS)

    Crabtree, K. N.; Indriolo, N.; Kreckel, H.; Kauffman, C. A.; Tom, B. A.; Becka, E.; McGuire, B. A.; McCall, B. J.

    2011-05-01

    Observations of diffuse molecular clouds have shown that the excitation temperature T(H_3^+) derived from the (J,K) = (1,0) (ortho) and (1,1) (para) rotational levels of H_3^+ does not necessarily agree with the kinetic temperature (T01) inferred from UV measurements of H_2. In four of the five diffuse molecular cloud sight lines for which both H_3^+ and H_2 observations are available, T(H_3^+) is lower than T01 by 30 K. The reaction H_3^+ + H_2 ? H_2 + H_3^+ is expected to thermalize the H_3^+ nuclear spin distribution, but the interplay of nuclear spin selection rules and energetic restrictions at the low temperatures of the diffuse interstellar medium may prevent full thermalization at steady state. Alternatively, the nonthermal distribution could arise if H_3^+ does not experience a sufficient number of thermalizing collisions with H_2 during its lifetime. We have studied the nuclear spin dependence of the reaction of H_3^+ with H_2 in the laboratory by measuring the ortho:para ratio of H_3^+ formed in plasmas of varying ortho:para H_2 ratios. This study was performed in a hollow cathode cell which enabled the first measurements of this reaction at low temperature (130 K). From these measurements, we derived the ratio of the ``proton hop'' and ``hydrogen exchange'' rate coefficients as a function of temperature. The ratio, ?, was found to decrease with temperature, already reaching the statistical limit of 0.5 at a temperature of 130 K. Knowledge of ? enables modeling of the ortho:para ratio of H_3^+ in diffuse molecular clouds. We have modeled the nuclear spin dependence of the formation, thermalization, and destruction processes of H_3^+, and found that the nonthermal distribution is not caused by nuclear spin selection rules or energetic restrictions in the H_3^+ + H_2 reaction. Rather, it is likely caused by incomplete thermalization prior to H_3^+ destruction via electron dissociative recombination.

  9. Nuclear Spin Dependence of Hydrogenic Plasmas in the Laboratory and the Diffuse Interstellar Medium

    NASA Astrophysics Data System (ADS)

    Crabtree, Kyle N.; Indriolo, Nick; Kreckel, Holger; Kauffman, Carrie A.; Tom, Brian A.; Beçka, Eftalda; McGuire, Brett A.; McCall, Benjamin J.

    2011-10-01

    Observations of diffuse molecular clouds have shown that the excitation temperature T(H3+) derived from the (J,K) = (1,0) (ortho) and (1,1) (para) rotational levels of H3+ does not necessarily agree with the kinetic temperature (T01) inferred from UV measurements of H2. In four of the five diffuse molecular cloud sight lines for which both H3+ and H2 observations are available, T(H3+) is lower than T01 by 30 K. The reaction H3+ + H2 ? H2 + H3+ is expected to thermalize the H3+ nuclear spin distribution, but the interplay of nuclear spin selection rules and energetic restrictions at the low temperatures of the diffuse interstellar medium may prevent full thermalization at steady state. Alternatively, the nonthermal distribution could arise if H3+ does not experience a sufficient number of thermalizing collisions with H2 during its lifetime. We have studied the nuclear spin dependence of the reaction of H3+ with H2 in the laboratory by measuring the ortho:para ratio of H3+ formed in plasmas of varying ortho:para H2 ratios. This study was performed in a hollow cathode cell which enabled the first measurements of this reaction at low temperature (130 K). From these measurements, we derived the ratio of the "proton hop" and "hydrogen exchange" rate coefficients as a function of temperature. The ratio, ?, was found to decrease with temperature, already reaching the statistical limit of 0.5 at a temperature of 130 K. Knowledge of ? enables modeling of the ortho:para ratio of H3+ in diffuse molecular clouds. We have modeled the nuclear spin dependence of the formation, thermalization, and destruction processes of H3+, and found that the nonthermal distribution is not caused by nuclear spin selection rules or energetic restrictions in the H3+ + H2 reaction. Rather, it is likely caused by incomplete thermalization prior to H3+ destruction via electron dissociative recombination.

  10. Symmetry-lowering lattice distortion at the spin reorientation in MnBi single crystals

    NASA Astrophysics Data System (ADS)

    McGuire, Michael A.; Cao, Huibo; Chakoumakos, Bryan C.; Sales, Brian C.

    2014-11-01

    Structural and physical properties determined by measurements on large single crystals of the anisotropic ferromagnet MnBi are reported. The findings support the importance of magnetoelastic effects in this material. X-ray diffraction reveals a structural phase transition at the spin reorientation temperature TS R=90 K. The distortion is driven by magnetoelastic coupling, and upon cooling transforms the structure from hexagonal to orthorhombic. Heat capacity measurements show a thermal anomaly at the crystallographic transition, which is suppressed rapidly by applied magnetic fields. Effects on the transport and anisotropic magnetic properties of the single crystals are also presented. Increasing anisotropy of the atomic displacement parameters for Bi with increasing temperature above TS R is revealed by neutron diffraction measurements. It is likely that this is directly related to the anisotropic thermal expansion in MnBi, which plays a key role in the spin reorientation and magnetocrystalline anisotropy. The identification of the true ground-state crystal structure reported here may be important for future experimental and theoretical studies of this permanent magnet material, which have to date been performed and interpreted using only the high-temperature structure.

  11. Single-spin asymmetries in W boson production at next-to-leading order

    NASA Astrophysics Data System (ADS)

    Ringer, Felix; Vogelsang, Werner

    2015-05-01

    We present an analytic next-to-leading-order QCD calculation of the partonic cross sections for single-inclusive lepton production in hadronic collisions, when the lepton originates from the decay of an intermediate electroweak boson and is produced at high transverse momentum. In particular, we consider the case of incoming longitudinally polarized protons for which parity-violating single-spin asymmetries arise that are exploited in the W boson program at RHIC to constrain the proton's helicity parton distributions. Our calculation enables a very fast and efficient numerical computation of the relevant spin asymmetries at RHIC, which is an important ingredient for the inclusion of RHIC data in a global analysis of nucleon helicity structure. We confirm the validity of our calculation by comparing it with an existing code that treats the next-to-leading-order cross sections entirely numerically by Monte Carlo integration techniques. We also provide new comparisons of the present RHIC data with results for some of the sets of polarized parton distributions available in the literature.

  12. Temperature induced Spin Switching in SmFeO3 Single Crystal

    PubMed Central

    Cao, Shixun; Zhao, Huazhi; Kang, Baojuan; Zhang, Jincang; Ren, Wei

    2014-01-01

    The prospect of controlling the magnetization (M) of a material is of great importance from the viewpoints of fundamental physics and future applications of emerging spintronics. A class of rare-earth orthoferrites RFeO3 (R is rare-earth element) materials exhibit striking physical properties of spin switching and magnetization reversal induced by temperature and/or applied magnetic field. Furthermore, due to the novel magnetic, magneto-optic and multiferroic properties etc., RFeO3 materials are attracting more and more interests in recent years. We have prepared and investigated a prototype of RFeO3 materials, namely SmFeO3 single-crystal. And we report magnetic measurements upon both field cooling (FC) and zero-field cooling (ZFC) of the sample, as a function of temperature and applied magnetic field. The central findings of this study include that the magnetization of single-crystal SmFeO3 can be switched by temperature, and tuning the magnitude of applied magnetic field allows us to realize such spin switching even at room temperature. PMID:25091202

  13. Temperature induced spin switching in SmFeO3 single crystal.

    PubMed

    Cao, Shixun; Zhao, Huazhi; Kang, Baojuan; Zhang, Jincang; Ren, Wei

    2014-01-01

    The prospect of controlling the magnetization (M) of a material is of great importance from the viewpoints of fundamental physics and future applications of emerging spintronics. A class of rare-earth orthoferrites RFeO3 (R is rare-earth element) materials exhibit striking physical properties of spin switching and magnetization reversal induced by temperature and/or applied magnetic field. Furthermore, due to the novel magnetic, magneto-optic and multiferroic properties etc., RFeO3 materials are attracting more and more interests in recent years. We have prepared and investigated a prototype of RFeO3 materials, namely SmFeO3 single-crystal. And we report magnetic measurements upon both field cooling (FC) and zero-field cooling (ZFC) of the sample, as a function of temperature and applied magnetic field. The central findings of this study include that the magnetization of single-crystal SmFeO3 can be switched by temperature, and tuning the magnitude of applied magnetic field allows us to realize such spin switching even at room temperature. PMID:25091202

  14. Nuclear-spin-induced cotton-mouton effect in a strong external magnetic field.

    PubMed

    Fu, Li-Juan; Vaara, Juha

    2014-08-01

    Novel, high-sensitivity and high-resolution spectroscopic methods can provide site-specific nuclear information by exploiting nuclear magneto-optic properties. We present a first-principles electronic structure formulation of the recently proposed nuclear-spin-induced Cotton-Mouton effect in a strong external magnetic field (NSCM-B). In NSCM-B, ellipticity is induced in a linearly polarized light beam, which can be attributed to both the dependence of the symmetric dynamic polarizability on the external magnetic field and the nuclear magnetic moment, as well as the temperature-dependent partial alignment of the molecules due to the magnetic fields. Quantum-chemical calculations of NSCM-B were conducted for a series of molecular liquids. The overall order of magnitude of the induced ellipticities is predicted to be 10(-11) -10(-6) rad?T(-1) ?M(-1) ?cm(-1) for fully spin-polarized nuclei. In particular, liquid-state heavy-atom systems should be promising for experiments in the Voigt setup. PMID:24862946

  15. Analytic treatment of nuclear spin-lattice relaxation for diffusion in a cone model

    NASA Astrophysics Data System (ADS)

    Sitnitsky, A. E.

    2011-12-01

    We consider nuclear spin-lattice relaxation rate resulted from a diffusion equation for rotational wobbling in a cone. We show that the widespread point of view that there are no analytical expressions for correlation functions for wobbling in a cone model is invalid and prove that nuclear spin-lattice relaxation in this model is exactly tractable and amenable to full analytical description. The mechanism of relaxation is assumed to be due to dipole-dipole interaction of nuclear spins and is treated within the framework of the standard Bloemberger, Purcell, Pound-Solomon scheme. We consider the general case of arbitrary orientation of the cone axis relative the magnetic field. The BPP-Solomon scheme is shown to remain valid for systems with the distribution of the cone axes depending only on the tilt relative the magnetic field but otherwise being isotropic. We consider the case of random isotropic orientation of cone axes relative the magnetic field taking place in powders. Also we consider the cases of their predominant orientation along or opposite the magnetic field and that of their predominant orientation transverse to the magnetic field which may be relevant for, e.g., liquid crystals. Besides we treat in details the model case of the cone axis directed along the magnetic field. The latter provides direct comparison of the limiting case of our formulas with the textbook formulas for free isotropic rotational diffusion. The dependence of the spin-lattice relaxation rate on the cone half-width yields results similar to those predicted by the model-free approach.

  16. Analytic treatment of nuclear spin-lattice relaxation for diffusion in a cone model

    E-print Network

    A. E. Sitnitsky

    2011-08-02

    We consider nuclear spin-lattice relaxation rate resulted from a diffusion equation for rotational wobbling in a cone. We show that the widespread point of view that there are no analytical expressions for correlation functions for wobbling in a cone model is invalid and prove that nuclear spin-lattice relaxation in this model is exactly tractable and amenable to full analytical description. The mechanism of relaxation is assumed to be due to dipole-dipole interaction of nuclear spins and is treated within the framework of the standard Bloemberger, Purcell, Pound - Solomon scheme. We consider the general case of arbitrary orientation of the cone axis relative the magnetic field. The BPP-Solomon scheme is shown to remain valid for systems with the distribution of the cone axes depending only on the tilt relative the magnetic field but otherwise being isotropic. We consider the case of random isotropic orientation of cone axes relative the magnetic field taking place in powders. Also we consider the cases of their predominant orientation along or opposite the magnetic field and that of their predominant orientation transverse to the magnetic field which may be relevant for, e.g., liquid crystals. Besides we treat in details the model case of the cone axis directed along the magnetic field. The latter provides direct comparison of the limiting case of our formulas with the textbook formulas for free isotropic rotational diffusion. The dependence of the spin-lattice relaxation rate on the cone half-width yields results similar to those predicted by the model-free approach.

  17. Nuclear spin of a new isomer in $^{119}Cs$ and magnetic moment of $^{120}Cs$: Evidence for strongly deformed nuclear shapes of the light cesium isotopes

    E-print Network

    Ekström, C; Heinemeier, J

    1978-01-01

    The nuclear spin, I=/sup 3///sub 2/, of a new isomer in /sup 119/Cs and the magnetic moment, mu /sub I/=3.92(5) nm, of /sup 120/Cs have been determined in on-line ABMR experiments at the ISOLDE facility, CERN. The experimental data give evidence for strongly deformed nuclear shapes of the light cesium isotopes. (10 refs).

  18. Demonstration of Quantum Entanglement between a Single Electron Spin Confined to an InAs Quantum Dot and a Photon

    NASA Astrophysics Data System (ADS)

    Schaibley, J. R.; Burgers, A. P.; McCracken, G. A.; Duan, L.-M.; Berman, P. R.; Steel, D. G.; Bracker, A. S.; Gammon, D.; Sham, L. J.

    2013-04-01

    The electron spin state of a singly charged semiconductor quantum dot has been shown to form a suitable single qubit for quantum computing architectures with fast gate times. A key challenge in realizing a useful quantum dot quantum computing architecture lies in demonstrating the ability to scale the system to many qubits. In this Letter, we report an all optical experimental demonstration of quantum entanglement between a single electron spin confined to a single charged semiconductor quantum dot and the polarization state of a photon spontaneously emitted from the quantum dot’s excited state. We obtain a lower bound on the fidelity of entanglement of 0.59±0.04, which is 84% of the maximum achievable given the timing resolution of available single photon detectors. In future applications, such as measurement-based spin-spin entanglement which does not require sub-nanosecond timing resolution, we estimate that this system would enable near ideal performance. The inferred (usable) entanglement generation rate is 3×103s-1. This spin-photon entanglement is the first step to a scalable quantum dot quantum computing architecture relying on photon (flying) qubits to mediate entanglement between distant nodes of a quantum dot network.

  19. Measurement of Single- and Double-Spin Asymmetries in Deep Inelastic Pion Electroproduction with a Longitudinally Polarized Target

    NASA Astrophysics Data System (ADS)

    Avakian, H.; Bosted, P.; Burkert, V. D.; Elouadrhiri, L.; Adhikari, K. P.; Aghasyan, M.; Amaryan, M.; Anghinolfi, M.; Baghdasaryan, H.; Ball, J.; Battaglieri, M.; Bedlinskiy, I.; Biselli, A. S.; Branford, D.; Briscoe, W. J.; Brooks, W.; Carman, D. S.; Casey, L.; Cole, P. L.; Collins, P.; Crabb, D.; Crede, V.; D'Angelo, A.; Daniel, A.; Dashyan, N.; de Vita, R.; de Sanctis, E.; Deur, A.; Dey, B.; Dhamija, S.; Dickson, R.; Djalali, C.; Dodge, G.; Doughty, D.; Dupre, R.; El Alaoui, A.; Eugenio, P.; Fegan, S.; Fersch, R.; Forest, T. A.; Fradi, A.; Gabrielyan, M. Y.; Gavalian, G.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Gohn, W.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guler, N.; Guo, L.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Hassall, N.; Heddle, D.; Hicks, K.; Holtrop, M.; Ilieva, Y.; Ireland, D. G.; Isupov, E. L.; Jawalkar, S. S.; Jo, H. S.; Joo, K.; Keller, D.; Khandaker, M.; Khetarpal, P.; Kim, W.; Klein, A.; Klein, F. J.; Konczykowski, P.; Kubarovsky, V.; Kuhn, S. E.; Kuleshov, S. V.; Kuznetsov, V.; Livingston, K.; Lu, H. Y.; Markov, N.; Mayer, M.; Martinez, D.; McAndrew, J.; McCracken, M. E.; McKinnon, B.; Meyer, C. A.; Mineeva, T.; Mirazita, M.; Mokeev, V.; Moreno, B.; Moriya, K.; Morrison, B.; Moutarde, H.; Munevar, E.; Nadel-Turonski, P.; Nasseripour, R.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Niroula, M. R.; Osipenko, M.; Ostrovidov, A. I.; Paremuzyan, R.; Park, K.; Park, S.; Pasyuk, E.; Anefalos Pereira, S.; Perrin, Y.; Pisano, S.; Pogorelko, O.; Price, J. W.; Procureur, S.; Prok, Y.; Protopopescu, D.; Raue, B. A.; Ricco, G.; Ripani, M.; Rosner, G.; Rossi, P.; Sabatié, F.; Saini, M. S.; Salamanca, J.; Salgado, C.; Schumacher, R. A.; Seder, E.; Seraydaryan, H.; Sharabian, Y. G.; Sober, D. I.; Sokhan, D.; Stepanyan, S. S.; Stepanyan, S.; Stoler, P.; Strauch, S.; Suleiman, R.; Taiuti, M.; Tedeschi, D. J.; Tkachenko, S.; Ungaro, M.; Vernarsky, B.; Vineyard, M. F.; Voutier, E.; Watts, D. P.; Weinstein, L. B.; Weygand, D. P.; Wood, M. H.; Zhang, J.; Zhao, B.; Zhao, Z. W.

    2010-12-01

    We report the first measurement of the transverse momentum dependence of double-spin asymmetries in semi-inclusive production of pions in deep-inelastic scattering off the longitudinally polarized proton. Data have been obtained using a polarized electron beam of 5.7 GeV with the CLAS detector at the Jefferson Lab (JLab). Modulations of single spin asymmetries over the azimuthal angle between lepton scattering and hadron production planes ? have been measured over a wide kinematic range in Bjorken x and virtual photon squared four-momentum Q2. A significant nonzero sin?2? single spin asymmetry was observed for the first time indicating strong spin-orbit correlations for transversely polarized quarks in the longitudinally polarized proton.

  20. Measurement of Single- and Double-Spin Asymmetries in Deep Inelastic Pion Electroproduction with a Longitudinally Polarized Target

    SciTech Connect

    Avakian, H.; Bosted, P.; Burkert, V. D.; Elouadrhiri, L.; Brooks, W.; Carman, D. S.; Deur, A.; Guo, L.; Kubarovsky, V.; Nadel-Turonski, P.; Weygand, D. P. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States); Adhikari, K. P.; Amaryan, M.; Dodge, G.; Gavalian, G.; Guler, N.; Klein, A.; Kuhn, S. E.; Niroula, M. R.; Seraydaryan, H. [Old Dominion University, Norfolk, Virginia 23529 (United States)

    2010-12-31

    We report the first measurement of the transverse momentum dependence of double-spin asymmetries in semi-inclusive production of pions in deep-inelastic scattering off the longitudinally polarized proton. Data have been obtained using a polarized electron beam of 5.7 GeV with the CLAS detector at the Jefferson Lab (JLab). Modulations of single spin asymmetries over the azimuthal angle between lepton scattering and hadron production planes {phi} have been measured over a wide kinematic range in Bjorken x and virtual photon squared four-momentum Q{sup 2}. A significant nonzero sin2{phi} single spin asymmetry was observed for the first time indicating strong spin-orbit correlations for transversely polarized quarks in the longitudinally polarized proton.

  1. Single spin asymmetry AN in polarized proton-proton elastic scattering at ?{s}=200 GeV

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alakhverdyants, A. V.; Alekseev, I.; Alford, J.; Anson, C. D.; Arkhipkin, D.; Aschenauer, E.; Averichev, G. S.; Balewski, J.; Banerjee, A.; Barnovska, Z.; Beavis, D. R.; Bellwied, R.; Betancourt, M. J.; Betts, R. R.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bruna, E.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Cai, X. Z.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chung, P.; Chwastowski, J.; Codrington, M. J. M.; Corliss, R.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derradi de Souza, R.; Dhamija, S.; Didenko, L.; Ding, F.; Dion, A.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Elnimr, M.; Engelage, J.; Eppley, G.; Eun, L.; Evdokimov, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Fersch, R. G.; Filip, P.; Finch, E.; Fisyak, Y.; Gagliardi, C. A.; Gangadharan, D. R.; Geurts, F.; Gibson, A.; Gliske, S.; Gorbunov, Y. N.; Grebenyuk, O. G.; Grosnick, D.; Gupta, S.; Guryn, W.; Haag, B.; Hajkova, O.; Hamed, A.; Han, L.-X.; Harris, J. W.; Hays-Wehle, J. P.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Huo, L.; Igo, G.; Jacobs, W. W.; Jena, C.; Judd, E. G.; Kabana, S.; Kang, K.; Kapitan, J.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Kikola, D. P.; Kiryluk, J.; Kisel, I.; Kisiel, A.; Kizka, V.; Klein, S. R.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Koroleva, L.; Korsch, W.; Kotchenda, L.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Lamont, M. A. C.; Landgraf, J. M.; LaPointe, S.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Leight, W.; LeVine, M. J.; Li, C.; Li, L.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lima, L. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Lu, Y.; Luo, X.; Luszczak, A.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Mall, O. I.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Mioduszewski, S.; Mitrovski, M. K.; Mohammed, Y.; Mohanty, B.; Mondal, M. M.; Morozov, B.; Munhoz, M. G.; Mustafa, M. K.; Naglis, M.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nogach, L. V.; Novak, J.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Oliveira, R. A. N.; Olson, D.; Ostrowski, P.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Plyku, D.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Powell, C. B.; Pruneau, C.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Redwine, R.; Reed, R.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Ruan, L.; Rusnak, J.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandacz, A.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, B.; Schmitz, N.; Schuster, T. R.; Seele, J.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shao, M.; Sharma, B.; Sharma, M.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; deSouza, U. G.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Steadman, S. G.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Sumbera, M.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szanto de Toledo, A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarini, L. H.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Tian, J.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, Q.; Wang, X. L.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Whitten, C.; Wieman, H.; Wissink, S. W.; Witt, R.; Witzke, W.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, N.; Xu, Q. H.; Xu, W.; Xu, Y.; Xu, Z.; Xue, L.; Yang, Y.; Yang, Y.; Yepes, P.; Yi, Y.; Yip, K.; Yoo, I.-K.

    2013-02-01

    We report a high precision measurement of the transverse single spin asymmetry AN at the center of mass energy ?{s}=200 GeV in elastic proton-proton scattering by the STAR experiment at RHIC. The AN was measured in the four-momentum transfer squared t range 0.003?|t|?0.035 (, the region of a significant interference between the electromagnetic and hadronic scattering amplitudes. The measured values of AN and its t-dependence are consistent with a vanishing hadronic spin-flip amplitude, thus providing strong constraints on the ratio of the single spin-flip to the non-flip amplitudes. Since the hadronic amplitude is dominated by the Pomeron amplitude at this ?{s}, we conclude that this measurement addresses the question about the presence of a hadronic spin flip due to the Pomeron exchange in polarized proton-proton elastic scattering.

  2. Single spin asymmetry AN in polarized proton-proton elastic scattering at s=200 GeV

    NASA Astrophysics Data System (ADS)

    STAR Collaboration; Adamczyk, L.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alakhverdyants, A. V.; Alekseev, I.; Alford, J.; Anson, C. D.; Arkhipkin, D.; Aschenauer, E.; Averichev, G. S.; Balewski, J.; Banerjee, A.; Barnovska, Z.; Beavis, D. R.; Bellwied, R.; Betancourt, M. J.; Betts, R. R.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bruna, E.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Cai, X. Z.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chung, P.; Chwastowski, J.; Codrington, M. J. M.; Corliss, R.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derradi de Souza, R.; Dhamija, S.; Didenko, L.; Ding, F.; Dion, A.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Elnimr, M.; Engelage, J.; Eppley, G.; Eun, L.; Evdokimov, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Fersch, R. G.; Filip, P.; Finch, E.; Fisyak, Y.; Gagliardi, C. A.; Gangadharan, D. R.; Geurts, F.; Gibson, A.; Gliske, S.; Gorbunov, Y. N.; Grebenyuk, O. G.; Grosnick, D.; Gupta, S.; Guryn, W.; Haag, B.; Hajkova, O.; Hamed, A.; Han, L.-X.; Harris, J. W.; Hays-Wehle, J. P.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Huo, L.; Igo, G.; Jacobs, W. W.; Jena, C.; Judd, E. G.; Kabana, S.; Kang, K.; Kapitan, J.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Kikola, D. P.; Kiryluk, J.; Kisel, I.; Kisiel, A.; Kizka, V.; Klein, S. R.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Koroleva, L.; Korsch, W.; Kotchenda, L.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Lamont, M. A. C.; Landgraf, J. M.; LaPointe, S.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Leight, W.; LeVine, M. J.; Li, C.; Li, L.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lima, L. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Lu, Y.; Luo, X.; Luszczak, A.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Mall, O. I.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Mioduszewski, S.; Mitrovski, M. K.; Mohammed, Y.; Mohanty, B.; Mondal, M. M.; Morozov, B.; Munhoz, M. G.; Mustafa, M. K.; Naglis, M.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nogach, L. V.; Novak, J.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Oliveira, R. A. N.; Olson, D.; Ostrowski, P.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Plyku, D.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Powell, C. B.; Pruneau, C.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Redwine, R.; Reed, R.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Ruan, L.; Rusnak, J.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandacz, A.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, B.; Schmitz, N.; Schuster, T. R.; Seele, J.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shao, M.; Sharma, B.; Sharma, M.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; deSouza, U. G.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Steadman, S. G.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Sumbera, M.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szanto de Toledo, A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarini, L. H.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Tian, J.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, Q.; Wang, X. L.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Whitten, C.; Wieman, H.; Wissink, S. W.; Witt, R.; Witzke, W.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, N.; Xu, Q. H.; Xu, W.; Xu, Y.; Xu, Z.; Xue, L.; Yang, Y.; Yang, Y.; Yepes, P.; Yi, Y.

    2013-02-01

    We report a high precision measurement of the transverse single spin asymmetry AN at the center of mass energy s=200 GeV in elastic proton-proton scattering by the STAR experiment at RHIC. The AN was measured in the four-momentum transfer squared t range 0.003?|t|?0.035 (, the region of a significant interference between the electromagnetic and hadronic scattering amplitudes. The measured values of AN and its t-dependence are consistent with a vanishing hadronic spin-flip amplitude, thus providing strong constraints on the ratio of the single spin-flip to the non-flip amplitudes. Since the hadronic amplitude is dominated by the Pomeron amplitude at this s, we conclude that this measurement addresses the question about the presence of a hadronic spin flip due to the Pomeron exchange in polarized proton-proton elastic scattering.

  3. Spin-orbit effects on nuclear state preparation at the S -T+ anti-crossing in double quantum dots

    NASA Astrophysics Data System (ADS)

    Rancic, Marko; Burkard, Guido

    2014-03-01

    We explore the interplay of spin-orbit and hyperfine effects on the nuclear preparation schemes in two-electron double quantum dots, e.g. in GaAs. The quantity of utmost interest is the electron spin decoherence time T2* in dependence of the number of sweeps through the electron spin singlet S triplet T+ anti-crossing. Decoherence of the electron spin is caused by the difference field induced by the nuclear spins. We study the case where a singlet S(2 , 0) is initialized, in which both electrons are in the left dot. Subsequently, the system is driven repeatedly through the anti-crossing and back using linear electrical bias sweeps. Our model describes the passage through the anti-crossing with a large number of equally spaced, step-like parameter increments. We develop a numerical method describing the nuclear spins fully quantum mechanically, which allows us to track their dynamics. Both Rashba and Dresselhaus spin-orbit terms do depend on the angle ? between the [ 110 ] crystallographic and the inter-dot axis. Our results show that the suppression of decoherence (and therefore the enhancement of T2*) is inversely proportional to the strength of the spin-orbit interaction, which is tuned by varying the angle ?. We acknowledge the S3Nano Marie Curie ITN for support and funding.

  4. Symmetry & Controllability for Spin Networks with a Single-Node Control

    E-print Network

    Xiaoting Wang; Peter Pemberton-Ross; Sophie G Schirmer

    2011-02-17

    We consider the relation of symmetries and subspace controllability for spin networks with XXZ coupling subject to control of a single node by a local potential (Z-control). Such networks decompose into excitation subspaces. Focusing on the single excitation subspace it is shown that for single-node Z-controls external symmetries are characterized by eigenstates of the system Hamiltonian that have zero overlap with the control node, and there are no internal symmetries. It is further shown that there are symmetries that persist even in the presence of random perturbations. For uniformly coupled XXZ chains a characterization of all possible symmetries is given, which shows a strong dependence on the position of the node we control. Finally, it is shown rigorously for uniform Heisenberg and XX chains subject to single-node Z-control that the lack of symmetry is not only necessary but sufficient for subspace controllability. The latter approach is then generalized to establish controllability results for simple branched networks.

  5. Research program in nuclear and solid state physics. [including pion absorption spectra and muon spin precession

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The survey of negative pion absorption reactions on light and medium nuclei was continued. Muon spin precession was studied using an iron target. An impulse approximation model of the pion absorption process implied that the ion will absorb almost exclusively on nucleon pairs, single nucleon absorption being suppressed by energy and momentum conservation requirements. For measurements on both paramagnetic and ferromagnetic iron, the external magnetic field was supplied by a large C-type electromagnet carrying a current of about 100 amperes.

  6. Measurement of Single and Double-Spin Asymmetries in Deep Inelastic Pion Electroproduction with a Longitudinally Polarized Target

    Microsoft Academic Search

    H. Avakian; P. Bosted; V. D. Burkert; L. Elouadrhiri; K. P. Adhikari; M. Aghasyan; M. Amaryan; M. Anghinolfi; H. Baghdasaryan; J. Ball; M. Battaglieri; I. Bedlinskiy; A. S. Biselli; D. Branford; W. J. Briscoe; D. S. Carman; L. Casey; P. L. Cole; P. Collins; D. Crabb; V. Crede; A. D'Angelo; A. Daniel; N. Dashyan; R. de Vita; E. de Sanctis; A. Deur; B. Dey; S. Dhamija; R. Dickson; C. Djalali; G. Dodge; D. Doughty; R. Dupre; A. El Alaoui; P. Eugenio; S. Fegan; R. Fersch; T. A. Forest; A. Fradi; M. Y. Gabrielyan; G. Gavalian; N. Gevorgyan; G. P. Gilfoyle; K. L. Giovanetti; F. X. Girod; W. Gohn; R. W. Gothe; K. A. Griffioen; M. Guidal; N. Guler; L. Guo; K. Hafidi; H. Hakobyan; C. Hanretty; N. Hassall; D. Heddle; K. Hicks; M. Holtrop; Y. Ilieva; D. G. Ireland; E. L. Isupov; S. S. Jawalkar; K. Joo; D. Keller; M. Khandaker; P. Khetarpal; W. Kim; A. Klein; F. J. Klein; P. Konczykowski; V. Kubarovsky; S. E. Kuhn; S. V. Kuleshov; V. Kuznetsov; K. Livingston; H. Y. Lu; N. Markov; M. Mayer; D. Martinez; J. McAndrew; M. E. McCracken; B. McKinnon; C. A. Meyer; T. Mineeva; M. Mirazita; V. Mokeev; B. Moreno; K. Moriya; B. Morrison; H. Moutarde; E. Munevar; P. Nadel-Turonski; R. Nasseripour; S. Niccolai; G. Niculescu; I. Niculescu; M. R. Niroula; M. Osipenko; A. I. Ostrovidov; R. Paremuzyan; S. Pisano; E. Pasyuk; S. Anefalos Pereira; Y. Perrin; O. Pogorelko; J. W. Price; S. Procureur; Y. Prok; D. Protopopescu; B. A. Raue; G. Ricco; M. Ripani; G. Rosner; P. Rossi; F. Sabatié; M. S. Saini; J. Salamanca; C. Salgado; R. A. Schumacher; E. Seder; H. Seraydaryan; Y. G. Sharabian; D. I. Sober; D. Sokhan; S. S. Stepanyan; P. Stoler; S. Strauch; R. Suleiman; M. Taiuti; D. J. Tedeschi; S. Tkachenko; M. Ungaro; B. Vernarsky; M. F. Vineyard; E. Voutier; D. P. Watts; L. B. Weinstein; D. P. Weygand; M. H. Wood; J. Zhang; B. Zhao; Z. W. Zhao

    2010-01-01

    We report the first measurement of the transverse momentum dependence of double-spin asymmetries in semi-inclusive production of pions in deep-inelastic scattering off the longitudinally polarized proton. Data have been obtained using a polarized electron beam of 5.7 GeV with the CLAS detector at the Jefferson Lab (JLab). Modulations of single spin asymmetries over the azimuthal angle between lepton scattering and

  7. Rotor design for high pressure magic angle spinning nuclear magnetic resonance.

    PubMed

    Turcu, Romulus V F; Hoyt, David W; Rosso, Kevin M; Sears, Jesse A; Loring, John S; Felmy, Andrew R; Hu, Jian Zhi

    2013-01-01

    High pressure magic angle spinning (MAS) nuclear magnetic resonance (NMR) with a sample spinning rate exceeding 2.1 kHz and pressure greater than 165 bar has never been realized. In this work, a new sample cell design is reported, suitable for constructing cells of different sizes. Using a 7.5 mm high pressure MAS rotor as an example, internal pressure as high as 200 bar at a sample spinning rate of 6 kHz is achieved. The new high pressure MAS rotor is re-usable and compatible with most commercial NMR set-ups, exhibiting low (1)H and (13)C NMR background and offering maximal NMR sensitivity. As an example of its many possible applications, this new capability is applied to determine reaction products associated with the carbonation reaction of a natural mineral, antigorite ((Mg,Fe(2+))(3)Si(2)O(5)(OH)(4)), in contact with liquid water in water-saturated supercritical CO(2) (scCO(2)) at 150 bar and 50°C. This mineral is relevant to the deep geologic disposal of CO(2), but its iron content results in too many sample spinning sidebands at low spinning rate. Hence, this chemical system is a good case study to demonstrate the utility of the higher sample spinning rates that can be achieved by our new rotor design. We expect this new capability will be useful for exploring solid-state, including interfacial, chemistry at new levels of high-pressure in a wide variety of fields. PMID:23220181

  8. Nuclear spin-lattice relaxation of 60 Co in ferromagnetic alloys Pt 99 Co 1 and Pd 99 Co 1

    Microsoft Academic Search

    M. Trhlík; B. Sedlák; M. Rotter; ?. Lešták; V. N. Pavlov; P. ?ížek; M. Finger; A. L. Erzinkyan; V. P. Parfenova; G. M. Gurevich

    1987-01-01

    Nuclear spin-lattice relaxation (SLR) of60Co in the systems Pt99Co1, Pd99Co1 has been studied by very low temperature nuclear orientation technique. The thermal cycling method has been used. The difference\\u000a of two orders of magnitude of Korringa constant has been found between Pt99Co1 and Pd99Co1.

  9. Room-temperature implementation of the Deutsch-Jozsa algorithm with a single electronic spin in diamond

    E-print Network

    Fazhan Shi; Xing Rong; Nanyang Xu; Ya Wang; Jie Wu; Bo Chong; Xinhua Peng; Juliane Kniepert; Rolf-Simon Schoenfeld; Wolfgang Harneit; Mang Feng; Jiangfeng Du

    2010-02-12

    The nitrogen-vacancy defect center (NV center) is a promising candidate for quantum information processing due to the possibility of coherent manipulation of individual spins in the absence of the cryogenic requirement. We report a room-temperature implementation of the Deutsch-Jozsa algorithm by encoding both a qubit and an auxiliary state in the electron spin of a single NV center. By thus exploiting the specific S=1 character of the spin system, we demonstrate how even scarce quantum resources can be used for test-bed experiments on the way towards a large-scale quantum computing architecture.

  10. Finite-temperature calculations for spin-polarized asymmetric nuclear matter with the lowest order constrained variational method

    SciTech Connect

    Bigdeli, M. [Department of Physics, Zanjan University, Post Office Box 45195-313, Zanjan (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha, Post Office Box 55134-441, Maragha (Iran, Islamic Republic of); Bordbar, G. H. [Department of Physics, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha, Post Office Box 55134-441, Maragha (Iran, Islamic Republic of); Poostforush, A. [Department of Physics, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of)

    2010-09-15

    The lowest order constrained variational technique has been used to investigate some of the thermodynamic properties of spin-polarized hot asymmetric nuclear matter, such as the free energy, symmetry energy, susceptibility, and equation of state. We have shown that the symmetry energy of the nuclear matter is substantially sensitive to the value of spin polarization. Our calculations show that the equation of state of the polarized hot asymmetric nuclear matter is stiffer for higher values of the polarization as well as the isospin asymmetry parameter. Our results for the free energy and susceptibility show that spontaneous ferromagnetic phase transition cannot occur for hot asymmetric matter.

  11. High-frequency electrical charge and spin control in a single InGaAs quantum dot

    NASA Astrophysics Data System (ADS)

    Nannen, J.; Quitsch, W.; Eliasson, S.; Kümmell, T.; Bacher, G.

    2012-01-01

    We report on the charging behavior of a single self-assembled InGaAs quantum dot with unpolarized and spin-polarized electrons under direct current (DC) and high-frequency biasing. The tunnel coupling of the quantum dot to a spin-polarized electron reservoir leads to characteristic voltage dependence of the polarization of the neutral and the negatively charged exciton emissions in a magnetic field under DC biasing conditions. Via high-frequency adaptation of the device, electrical control of the charge state of the single quantum dot in the gigahertz regime is achieved. A technique for optical preparation of single holes and subsequent electrical charging via high-frequency voltage pulses allows for an ultrafast injection and readout of spin-polarized electrons on a subnanosecond timescale.

  12. Electrical Nuclear Quadrupolar Interaction of ZINC67 in a Single Crystal of Zinc

    Microsoft Academic Search

    Jacques Goyette

    1986-01-01

    The nuclear quadrupolar coupling of ('67)Zn in a single crystal of zinc has been studied using the techniques of nuclear acoustic resonance (NAR) and nuclear magnetic resonance (NMR) at low temperatures. NAR, which is an attractive way of doing resonance experiments, is analogous to NMR except in the fact that we use phonons instead of photons to induce transitions thereby

  13. Effects of the covalent linker groups on the spin transport properties of single nickelocene molecules attached to single-walled carbon nanotubes.

    PubMed

    Wei, Peng; Sun, Lili; Benassi, Enrico; Shen, Ziyong; Sanvito, Stefano; Hou, Shimin

    2012-05-21

    The understanding of how the spin moment of a magnetic molecule transfers to a carbon nanotube, when the molecule is attached to it, is crucial for designing novel supramolecular spin devices. Here we explore such an issue by modeling the spin transport of a single-walled carbon nanotube grafted with one nickelocene molecule. In particular we investigate how the electron transport becomes spin-polarized depending on the specific linking group bonding nickelocene to the nanotube. We consider as linkers both aziridine and pyrrolidine rings and the amide group. Our calculations show that, at variance with aziridine, both pyrrolidine and amide, do alter the sp(2) character of the binding site of the nanotube and thus affect the transmission around the Fermi level. However, only aziridine allows transferring the spin polarization of the nickelocene to the nanotube, whose conductance at the Fermi level becomes spin-polarized. This suggests the superiority of aziridine as a linker for grafting magnetic molecules onto carbon nanotubes with efficient spin filtering functionality. PMID:22612109

  14. All-optical preparation of coherent dark states of a single rare earth ion spin in a crystal

    E-print Network

    Kangwei Xia; Roman Kolesov; Ya Wang; Petr Siyushev; Rolf Reuter; Thomas Kornher; Nadezhda Kukharchyk; Andreas D. Wieck; Bruno Villa; Sen Yang; Jörg Wrachtrup

    2015-06-22

    All-optical addressing and control of single solid-state based qubits allows for scalable architectures of quantum devices such as quantum networks and quantum simulators. So far, all-optical addressing of qubits was demonstrated only for color centers in diamond and quantum dots. Here, we demonstrate generation of coherent dark state of a single rare earth ion in a solid, namely a cerium ion in yttrium aluminum garnet (YAG). The dark state was formed under the condition of coherent population trapping. Furthermore, high-resolution spectroscopic studies of native and implanted single Ce ions have been performed. They revealed narrow and spectrally stable optical transitions between the spin sublevels of the ground and excited optical states, indicating the feasibility of interfacing single photons with a single electron spin of a cerium ion.

  15. Magic radio-frequency dressing of nuclear spins in high-accuracy optical clocks.

    PubMed

    Zanon-Willette, Thomas; de Clercq, Emeric; Arimondo, Ennio

    2012-11-30

    A Zeeman-insensitive optical clock atomic transition is engineered when nuclear spins are dressed by a nonresonant radio-frequency field. For fermionic species as (87)Sr, (171)Yb, and (199)Hg, particular ratios between the radio-frequency driving amplitude and frequency lead to "magic" magnetic values where a net cancelation of the Zeeman clock shift and a complete reduction of first-order magnetic variations are produced within a relative uncertainty below the 10(-18) level. An Autler-Townes continued fraction describing a semiclassical radio-frequency dressed spin is numerically computed and compared to an analytical quantum description including higher-order magnetic field corrections to the dressed energies. PMID:23368116

  16. Impact of hadronic and nuclear corrections on global analysis of spin-dependent parton distributions

    SciTech Connect

    Jimenez-Delgado, Pedro [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Accardi, Alberto [Hampton University, Hampton, VA (United States); Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Melnitchouk, Wally [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2014-02-01

    We present the first results of a new global next-to-leading order analysis of spin-dependent parton distribution functions from the most recent world data on inclusive polarized deep-inelastic scattering, focusing in particular on the large-x and low-Q^2 regions. By directly fitting polarization asymmetries we eliminate biases introduced by using polarized structure function data extracted under nonuniform assumptions for the unpolarized structure functions. For analysis of the large-x data we implement nuclear smearing corrections for deuterium and 3He nuclei, and systematically include target mass and higher twist corrections to the g_1 and g_2 structure functions at low Q^2. We also explore the effects of Q^2 and W^2 cuts in the data sets, and the potential impact of future data on the behavior of the spin-dependent parton distributions at large x.

  17. Spin-isospin nuclear response using the existing microscopic Skyrme functionals

    SciTech Connect

    Fracasso, S.; Colo, G. [Dipartmento di Fisica, Universita degli Studi and INFN, Sezione di Milano, I-20133 Milano (Italy)

    2007-10-15

    Our paper aims at providing an answer to the question of whether one can reliably describe the properties of the most important spin-isospin nuclear excitations by using the available nonrelativistic Skyrme energy functionals. Our method, which has been introduced in a previous publication devoted to the isobaric analog states, is the self-consistent quasiparticle random-phase approximation (QRPA). The inclusion of pairing is instrumental for describing a number of experimentally measured spherical systems which are characterized by open shells. We discuss the effect of isoscalar and isovector pairing correlations. Based on the results for the Gamow-Teller resonance in {sup 90}Zr, {sup 208}Pb, and a few Sn isotopes, we draw definite conclusions on the performance of different Skyrme parametrizations, and we suggest improvements for future fits. We also use the spin-dipole resonance as a benchmark of our statements.

  18. EDM measurement in 129Xe atom using dual active feedback nuclear spin maser

    NASA Astrophysics Data System (ADS)

    Sato, T.; Ichikawa, Y.; Ohtomo, Y.; Sakamoto, Y.; Kojima, S.; Funayama, C.; Suzuki, T.; Chikamori, M.; Hikota, E.; Tsuchiya, M.; Furukawa, T.; Yoshimi, A.; Bidinosti, C. P.; Ino, T.; Ueno, H.; Matsuo, Y.; Fukuyama, T.; Asahi, K.

    2015-04-01

    The technique of an active nuclear spin maser is adopted in the search for electric dipole moment in a diamagnetic atom 129Xe. In order to reduce systematic uncertainties arising from long-term drifts of the external magnetic field and from the contact interaction between longitudinal polarized Rb atoms and 129Xe spin, a 3He comagnetometer with a double-cell geometry was employed. The remaining shift, which turned out to show some correlation with the cell temperature, was mitigated by stabilizing the cell temperature. As a result, the frequency drift of the 129Xe maser was reduced from 12 mHz to 700 ?Hz, and the determination precision of frequency of 8.7 nHz was obtained for a 2×104 s measurement time using the double-cell geometry cell.

  19. Nuclear magnetic resonance study of spin relaxation and magnetic field gradients in maple leaves.

    PubMed

    McCain, D C

    1995-09-01

    1H Nuclear magnetic resonance techniques were used to measure the distributions of spin-spin relaxation times, T2, and of magnetic field gradients in both the chloroplast and nonchloroplast water compartments of maple leaves (Acer platanoides). Results showed that encounters between water molecules and membranes inside chloroplasts provide an inefficient relaxation mechanism; i.e., chloroplast membranes interact weakly with water molecules. Gradient measurements indirectly measured the sizes of chloroplasts by showing that water in the chloroplasts is confined to small compartments a few microns in diameter. A comparison between measured gradients and gradients calculated for a model leaf indicated that chloroplasts are somewhat more likely to occupy positions along cell walls adjacent to air spaces, but also they may be found in the interiors of cells. PMID:8519965

  20. Spin-isospin nuclear response using the existing microscopic Skyrme functionals

    E-print Network

    Sara Fracasso; Gianluca Colo'

    2007-04-22

    Our paper aims at providing an answer to the question whether one can reliably describe the properties of the most important spin-isospin nuclear excitations, by using the available non-relativistic Skyrme energy functionals. Our method, which has been introduced in a previous publication devoted to the Isobaric Analog states, is the self-consistent Quasiparticle Random Phase Approximation (QRPA). The inclusion of pairing is instrumental for describing a number of experimentally measured spherical systems which are characterized by open shells. We discuss the effect of isoscalar and isovector pairing correlations. Based on the results for the Gamow-Teller resonance in $^{90}$Zr, in $^{208}$Pb and in few Sn isotopes, we draw definite conclusions on the performance of different Skyrme parametrizations, and we suggest improvements for future fits. We also use the spin-dipole resonance as a benchmark of our statements.

  1. Size dependence of 13C nuclear spin-lattice relaxation in micro- and nanodiamonds.

    PubMed

    Panich, A M; Sergeev, N A; Shames, A I; Osipov, V Yu; Boudou, J-P; Goren, S D

    2015-02-25

    Size dependence of physical properties of nanodiamond particles is of crucial importance for various applications in which defect density and location as well as relaxation processes play a significant role. In this work, the impact of defects induced by milling of micron-sized synthetic diamonds was studied by magnetic resonance techniques as a function of the particle size. EPR and (13)C NMR studies of highly purified commercial synthetic micro- and nanodiamonds were done for various fractions separated by sizes. Noticeable acceleration of (13)C nuclear spin-lattice relaxation with decreasing particle size was found. We showed that this effect is caused by the contribution to relaxation coming from the surface paramagnetic centers induced by sample milling. The developed theory of the spin-lattice relaxation for such a case shows good compliance with the experiment. PMID:25646270

  2. Nuclear Spin relaxation mediated by Fermi-edge electrons in n-type GaAs

    NASA Astrophysics Data System (ADS)

    Kotur, M.; Dzhioev, R. I.; Kavokin, K. V.; Korenev, V. L.; Namozov, B. R.; Pak, P. E.; Kusrayev, Yu. G.

    2014-03-01

    A method based on the optical orientation technique was developed to measure the nuclear-spin lattice relaxation time T 1 in semiconductors. It was applied to bulk n-type GaAs, where T 1 was measured after switching off the optical excitation in magnetic fields from 400 to 1200 G at low (< 30 K) temperatures. The spin-lattice relaxation of nuclei in the studied sample with n D = 9 × 1016 cm-3 was found to be determined by hyperfine scattering of itinerant electrons (Korringa mechanism) which predicts invariability of T 1 with the change in magnetic field and linear dependence of the relaxation rate on temperature. This result extends the experimentally verified applicability of the Korringa relaxation law in degenerate semiconductors, previously studied in strong magnetic fields (several Tesla), to the moderate field range.

  3. Dynamic nuclear polarization of carbonyl and methyl 13C spins in acetate using trityl OX063

    NASA Astrophysics Data System (ADS)

    Niedbalski, Peter; Parish, Christopher; Lumata, Lloyd

    2015-03-01

    Hyperpolarization via dissolution dynamic nuclear polarization (DNP) is a physics technique that amplifies the magnetic resonance signals by several thousand-fold for biomedical NMR spectroscopy and imaging (MRI). Herein we have investigated the effect of carbon-13 isotopic location on the DNP of acetate (one of the biomolecules commonly used for hyperpolarization) at 3.35 T and 1.4 K using a narrow ESR linewidth free radical trityl OX063. We have found that the carbonyl 13C spins yielded about twice the polarization produced in methyl 13C spins. Deuteration of the methyl group, beneficial in the liquid-state, did not produce an improvement in the polarization level at cryogenic conditions. Concurrently, the solid-state nuclear relaxation of these samples correlate with the polarization levels achieved. These results suggest that the location of the 13C isotopic labeling in acetate has a direct impact on the solid-state polarization achieved and is mainly governed by the nuclear relaxation leakage factor.

  4. Enantiodiscrimination and extraction of short and long range homo- and hetero-nuclear residual dipolar couplings by a spin selective correlation experiment

    NASA Astrophysics Data System (ADS)

    Nath, Nilamoni; Suryaprakash, N.

    2010-08-01

    A two dimensional correlation experiment for the measurement of short and long range homo- and hetero- nuclear residual dipolar couplings (RDCs) from the broad and featureless proton NMR spectra including 13C satellites is proposed. The method employs a single natural abundant 13C spin as a spy nucleus to probe all the coupled protons and permits the determination of RDCs of negligible strengths. The technique has been demonstrated for the study of organic chiral molecules aligned in chiral liquid crystal, where additional challenge is to unravel the overlapped spectrum of enantiomers. The significant advantage of the method is demonstrated in better chiral discrimination using homonuclear RDCs as additional parameters.

  5. Single-spin asymmetries in the leptoproduction of transversely polarized ? hyperons

    DOE PAGESBeta

    Kanazawa, K.; Metz, A.; Pitonyak, D.; Schlegel, M.

    2015-05-01

    We analyze single-spin asymmetries (SSAs) in the leptoproduction of transversely polarized ? hyperons within the collinear twist-3 formalism. We calculate both the distribution and fragmentation terms in two different gauges (lightcone and Feynman) and show that the results are identical. This is the first time that the fragmentation piece has been analyzed for transversely polarized hadron production within the collinear twist-3 framework. In lightcone gauge we use the same techniques that were employed in computing the analogous piece in p? p ? ? X, which has become an important part to that reaction. With this in mind, we also verifymore »the gauge invariance of the formulas for the transverse SSA in the leptoproduction of pions. (author)« less

  6. Single-spin asymmetries in the leptoproduction of transversely polarized ? hyperons

    NASA Astrophysics Data System (ADS)

    Kanazawa, K.; Metz, A.; Pitonyak, D.; Schlegel, M.

    2015-05-01

    We analyze single-spin asymmetries (SSAs) in the leptoproduction of transversely polarized ? hyperons within the collinear twist-3 formalism. We calculate both the distribution and fragmentation terms in two different gauges (lightcone and Feynman) and show that the results are identical. This is the first time that the fragmentation piece has been analyzed for transversely polarized hadron production within the collinear twist-3 framework. In lightcone gauge we use the same techniques that were employed in computing the analogous piece in p? p ? ? X, which has become an important part to that reaction. With this in mind, we also verify the gauge invariance of the formulas for the transverse SSA in the leptoproduction of pions.

  7. Helicity asymmetry E measurement for single ?0 photoproduction with a frozen spin target

    NASA Astrophysics Data System (ADS)

    Iwamoto, Hideko; CLAS Collaboration

    2012-04-01

    The helicity asymmetry for single neutral pion photoproduction was measured using the CLAS detector in Hall B at the Thomas Jefferson National Accelerator Facility. This measurement used longitudinally polarized protons and circularly polarized photons with photon energis between 0.35 GeV to 2.4 GeV. The target was a frozen-spin butanol (C4H9OH) target, polarized at about 85%. The helicity asymmetry E for the ?p?p?0 was measured with missing-mass technique at the high statistics of about 12×106 events. The experimental results are compared to three available theoretical predictions, SAID, MAID, and EBAC. The preliminary results are in good agreement with the model calculations at low E? energy bins. However, a significant deviation is observed at high energy bins. Therefore, the new data will help to constrain the parameters of the theoretical models.

  8. The role of three-gluon correlation functions in the single spin asymmetry

    NASA Astrophysics Data System (ADS)

    Beppu, Hiroo; Kanazawa, Koichi; Koike, Yuji; Yoshida, Shinsuke

    2015-01-01

    We study the twist-3 three-gluon contribution to the single spin asymmetry in the light-hadron production in pp collision in the framework of the collinear factorization. We derive the corresponding cross section formula in the leading order with respect to the QCD coupling constant. We also present a numerical calculation of the asymmetry at the RHIC energy, using a model for the three-gluon correlation functions suggested by the asymmetry for the D-meson production at RHIC. We found that the asymmetries for the light-hadron and the jet productions are very useful to constrain the magnitude and form of the correlation functions. Since the three-gluon correlation functions shift the asymmetry for all kinds of hadrons in the same direction, it is unlikely that they become a main source of the asymmetry.

  9. Longitudinal-transverse double-spin asymmetries in single-inclusive leptoproduction of hadrons

    NASA Astrophysics Data System (ADS)

    Kanazawa, K.; Metz, A.; Pitonyak, D.; Schlegel, M.

    2015-03-01

    We analyze the longitudinal-transverse double-spin asymmetry in lepton-nucleon collisions where a single hadron is detected in the final state, i.e., ? ? N? ? h X. This is a subleading-twist observable in collinear factorization, and we look at twist-3 effects in both the transversely polarized nucleon and the unpolarized outgoing hadron. Results are anticipated for this asymmetry from both HERMES and Jefferson Lab Hall A, and it could be measured as well at COMPASS and a future Electron-Ion Collider. We also perform a numerical study of the distribution term, which, when compared to upcoming experimental results, could allow one to learn about the "worm-gear"-type function g ˜ (x) as well as assess the role of quark-gluon-quark correlations in the initial-state nucleon and twist-3 effects in the fragmenting unpolarized hadron.

  10. Single-spin asymmetries in the leptoproduction of transversely polarized ? hyperons

    DOE PAGESBeta

    Kanazawa, K. [Temple Univ., Philadelphia, PA (United States); Metz, A. [Temple Univ., Philadelphia, PA (United States); Pitonyak, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Schlegel, M. [Tubingen Univ., Tubingen (Germany)

    2015-05-01

    We analyze single-spin asymmetries (SSAs) in the leptoproduction of transversely polarized ? hyperons within the collinear twist-3 formalism. We calculate both the distribution and fragmentation terms in two different gauges (lightcone and Feynman) and show that the results are identical. This is the first time that the fragmentation piece has been analyzed for transversely polarized hadron production within the collinear twist-3 framework. In lightcone gauge we use the same techniques that were employed in computing the analogous piece in p? p ? ? X, which has become an important part to that reaction. With this in mind, we also verify the gauge invariance of the formulas for the transverse SSA in the leptoproduction of pions. (author)

  11. The Calculation of Indirect Nuclear SpinSpin Coupling Constants in Large Mark A. Watson,[b

    E-print Network

    Helgaker, Trygve

    ±4] This restriction, which arises from the severe demands that such calculations place on the description- able theoretical prediction of spin±spin coupling constants stems from a central application area±spin coupling constants in large molecular systems, performed using density functional theory. Such calculations

  12. Cu nuclear magnetic resonance of aligned single crystals of YBaâCuâOâ. sqrt. \\/sub delta

    Microsoft Academic Search

    C. H. Pennington; D. J. Durand; D. B. Zax; C. P. Slichter; J. P. Rice; D. M. Ginsberg

    1988-01-01

    There are two types of Cu sites in YBaâCuâOâ..sqrt..\\/sub delta\\/, plane and chain. One gives a nuclear quadrupole resonance (NQR) at 22.0 MHz, the other at 31.5 MHz. Measurements of nuclear spin-lattice relaxation time in the superconducting state show that the 31.5-MHz site has a much larger energy gap (as though its T\\/sub c\\/ were 200 K), but different experimental

  13. Cu nuclear magnetic resonance of aligned single crystals of YBa2Cu3O7-delta

    Microsoft Academic Search

    C. H. Pennington; D. J. Durand; D. B. Zax; C. P. Slichter; J. P. Rice; D. M. Ginsberg

    1988-01-01

    There are two types of Cu sites in YBa2Cu3O7-delta, plane and chain. One gives a nuclear quadrupole resonance (NQR) at 22.0 MHz, the other at 31.5 MHz. Measurements of nuclear spin-lattice relaxation time in the superconducting state show that the 31.5-MHz site has a much larger energy gap (as though its Tc were 200 K), but different experimental workers have

  14. Incompressibility and single-particle potential for asymmetric nuclear matter with Skyrme potential

    Microsoft Academic Search

    H. M. M. Mansour; Z. Metawei

    2006-01-01

    The incompressibility and the single-particle potential of asymmetric nuclear matter have been investigated in the framework\\u000a of the Skyrme interaction. These parameters have been studied as functions of the nuclear density, the neutron excess parameter,\\u000a and the temperature. The ratio of the isothermal incompressibility of hot nuclear matter to the incompressibility of cold\\u000a nuclear matter for different values of neutron

  15. Interlayer transport of nuclear spin polarization in ν = 2/3 quantum Hall states

    NASA Astrophysics Data System (ADS)

    Tsuda, S.; Nguyen, M. H.; Terasawa, D.; Fukuda, A.; Zheng, Y. D.; Arai, T.; Sawada, A.

    2013-12-01

    We investigated the interlayer diffusion of nuclear spin polarization (NSP) by using the phase transition point of quantum Hall states at a Landau level filling factor of ? ? 2/3 in a double quantum well sample. When the NSP is current-pumped in one layer, the magnetoresistance in the other layer is enhanced after a delay of 150 s and the raising speed of this layer is lower than that of the pumped layer. The delay and lower value of the raising speed are explained by the diffusion of NSP.

  16. Depression of the interlayer Josephson coupling in Bi2Sr2CaCu2O8x single crystals by spin-polarized

    E-print Network

    Lee, Hu-Jong

    Depression of the interlayer Josephson coupling in Bi2Sr2CaCu2O8þx single crystals by spin of Science and Technology, Pohang 790-784, South Korea Abstract We studied the effect of spin. Spin- injection through the Co electrode caused pair breaking in the CuO2 double layers, which led

  17. Processing, spinning, and fabrication of continuous fibers of single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Booker, Richard Delane

    Single-walled carbon nanotubes (SWNTs) show great promise for use in a wide range of applications. One of the most promising avenues for attaining these applications is the dispersion of SWNTs at high concentrations in superacids and processing into macroscopic articles such as fibers or films. Fibers spun from SWNT/superacid dispersions indicate that the morphology of the starting SWNT material influences the final morphology of the as-spun fiber. Here, we describe a method (termed disentanglement) of dispersing SWNTs in superacids and treating them using a high-shear, rotor/stator homogenizer, followed by coagulation to recover the solid SWNT material for use in fiber spinning. Several lines of experimental evidence (rheology and optical microscopy of the SWNTs in solution, scanning electron microscopy (SEM) of the coagulated material, and SEM of fibers spun from the coagulated material) show that this disentanglement treatment radically improves the degree of alignment in the SWNTs' morphology, which in turn improves the dispersibility and processability. Raman microscopy and thermogravimetric analysis (TGA) before and after homogenization show that the treatment does not damage the SWNTs. Although this technique is particularly important as a pre-processing step for fiber spinning of neat SWNT fibers, it is also useful for neat SWNT films, SWNT/polymer composites, and surfactant- or polymer-stabilized SWNT dispersions. Macroscopic neat SWNT fibers were successfully produced and characterized. Studies on coagulated fiber morphology suggest that slow acid removal is crucial to minimizing voids. Better SWNT coalescence and alignment were obtained by using appropriate coagulant and dope concentration. SWNTs were disentangled and dissolved at high concentrations (8 - 10 wt%) in 102% sulfuric acid. Fibers were subsequently extruded by dry-jet wet spinning into ice water and polyvinyl alcohol (PVA) / ice water. Drawing the fiber continuously while spinning further aligned the SWNTs within the fiber. The use of PVA (< 1%) in the coagulant slowed acid removal allowing better SWNT coalescence without damaging the SWNT electrical properties. The resulting combination of pre-processing and fiber drawing shows a threefold improvement in fiber tensile strength.

  18. Analytical theory of the nuclear-spin-induced optical rotation in liquids

    NASA Astrophysics Data System (ADS)

    Yao, Guo-hua; He, Ming; Chen, Dong-ming; He, Tian-jing; Liu, Fan-chen

    2011-08-01

    Based on the thought on the antisymmetric polarizability induced by nuclear magnetic moments and theory of the Faraday effect, an analytical theoretical expression is derived for the nuclear-spin-induced optical rotation (NSOR) of diamagnetic saturated molecules in a circular cylinder. That consists of two parts, ? and ?, induced by the intramolecular and intermolecular hyperfine interaction, respectively. By using them and the Verdet constants, NSOR for 1H in water, hexane, cyclohexane and methyl-alcohol in liquid and H 2 gas have been calculated. The calculated NSOR for water agrees with the experiment and for three hydrocarbons predicts the same order of magnitude as water. For the samples studied except H 2 gas, ? and ? are comparable in magnitude.

  19. High-resolution {sup 13}C nuclear magnetic resonance evidence of phase transition of Rb,Cs-intercalated single-walled nanotubes

    SciTech Connect

    Bouhrara, M.; Saih, Y. [KAUST Catalysis Center (KCC) King Abdullah University of Science and Technology, Thuwal (Saudi Arabia); Waagberg, T. [Department of Physics, Umeaa University, 901 87 Umeaa (Sweden); Goze-Bac, C. [LCVN, Universite Montpellier II, Place E. Bataillon, 34095 Montpellier (France); Abou-Hamad, E. [KAUST Catalysis Center (KCC) King Abdullah University of Science and Technology, Thuwal (Saudi Arabia); Department of Physics, Umeaa University, 901 87 Umeaa (Sweden); LCVN, Universite Montpellier II, Place E. Bataillon, 34095 Montpellier (France)

    2011-09-01

    We present 13 C high-resolution magic-angle-turning (MAT) and magic angle spinning nuclear magnetic resonance data of Cs and Rb intercalated single walled carbon nanotubes. We find two distinct phases at different intercalation levels. A simple charge transfer is applicable at low intercalation level. The new phase at high intercalation level is accompanied by a hybridization of alkali (s) orbitals with the carbon (sp2) orbitals of the single walled nanotubes, which indicate bundle surface sites is the most probable alkali site.

  20. Chain of nuclear spins system quantum computer taking into account second neighbor Ising spins interaction and numerical simulation of Shor factorization of N=4

    E-print Network

    Gustavo V. Lopez; Lorena Lara

    2006-08-28

    For a one-dimensional chain of four nuclear spins (1/2) and taking into account first and second neighbor interactions among the spin system, we make the numerical simulation of Shor prime factorization algorithm of the integer number N=4 to study the influence of the second neighbor interaction on the performance of this algorithm. It is shown that the optimum Rabi's frequency to control the non-resonant effects is dominated by the second neighbor interaction coupling parameter ($J'$), and that a good Shor quantum factorization is achieved for a ratio of second to first coupling constant of $J'/J\\ge 0.04$.

  1. Dislocation jump distances during creep of pure and doped NaCl single crystals using nuclear magnetic resonance pulse techniques

    NASA Astrophysics Data System (ADS)

    Murty, K. Linga; Kanert, O.

    1990-03-01

    Jump distances of dislocations are determined from the spin-lattice relaxation rates in a rotating frame [1/T1?] using in situ nuclear magnetic resonance pulse techniques during creep of pure and doped NaCl single crystals. Effects of divalent impurity and solid solution are investigated by doping with Ca and LiCl, respectively. Compression creep tests were performed at 10-30 MPa at 473 K. Relaxation rates were evaluated from spin-echo heights following ?/2, locking, and 64° pulse sequence. The amplitude of the spin echo decreased as soon as the load was applied following which it increased until the steady-state creep was reached, at which point a saturation value was observed. Mean jump distance of the mobile dislocations decreased with strain during the transient creep reaching a constant value at the onset and during the secondary creep. While the addition of 0.01 Ca has negligible influence on the jump distance, a solid solution with 0.01 LiCl resulted in about a four-fold increase. The results are compared and correlated with various microstructural parameters.

  2. Optical spin orientation of a single manganese atom in a semiconductor quantum dot using quasi-resonant excitation

    E-print Network

    Boyer, Edmond

    Optical spin orientation of a single manganese atom in a semiconductor quantum dot using quasi-resonant localized in a semiconductor quantum dot using quasi-resonant excitation at zero magnetic field. Optically the circular polarization of the excitation reflect the dynamics of this optical orientation mechanism

  3. Azimuthal single-spin asymmetries in semi-inclusive deep-inelastic scattering on a transversely polarised hydrogen target

    E-print Network

    Markus Diefenthaler

    2006-12-06

    Azimuthal single-spin asymmetries (SSA) in semi-inclusive electroproduction of charged pions and kaons in deep-inelastic scattering of positrons on a transversely polarised hydrogen target were observed. SSA amplitudes for both the Collins and the Sivers mechanism are presented.

  4. Observation of Spin Exchange Between the Singly Ionized Xe+ Ground State and the Metastable State of Neutral Xenon

    Microsoft Academic Search

    Tetsuo Hadeishi; Chung-Heng Liu

    1966-01-01

    We have observed spin-exchange collisions between the singly ionized 2P32 ground state of Xe and the 3P2 metastable state of neutral Xe, both formed and aligned by electronic-impact excitation under space-charge neutralization. Extension to the rf spectroscopy of the ionized ground state of other noble-gas atoms seems promising.

  5. Prediction of nuclear spin based on the behavior of ?-particle preformation probability

    NASA Astrophysics Data System (ADS)

    Ismail, M.; Adel, A.

    2013-11-01

    A realistic density-dependent nucleon-nucleon (NN) interaction with a finite-range exchange part which produces the nuclear matter saturation curve and the energy dependence of the nucleon-nucleus optical model potential is used to calculate the microscopic ?-nucleus potential in the well-established double-folding model. The main effect of antisymmetrization under exchange of nucleons between the ? and daughter nuclei has been included in the folding model through the finite-range exchange part of the NN interaction. The ?-decay half-lives have been determined using a microscopic potential within the semiclassical Wentzel-Kramers-Brillouin approximation in combination with the Bohr-Sommerfeld quantization condition. We systematically studied the preformation probability, S?, for ten even-even and odd mass heavy nuclei from Po to No isotopes. We found that S? has a regular behavior with N if the ? particle emitted from adjacent isotopes comes from the same energy levels or from a group of levels, assuming that the order of levels in this group is not changed. Sudden increase in S? is found when protons and neutrons holes exist below the Fermi levels. Based on the similarity in the behavior of S? with the neutron number for two adjacent nuclei, we try to determine the unknown or doubted nuclear spins and parities or at least correlate spins of adjacent nuclei.

  6. Using Single Quantum States as Spin Filters to Study Spin Polarization in Ferromagnets Mandar M. Deshmukh and D. C. Ralph

    E-print Network

    Deshmukh, Mandar M.

    a ferromagnet and individual energy levels in an aluminum quantum dot, we show how spin-resolved quantum states by other techniques in larger devices having continuous densities of electronic states. By prob- ingK. Beyond a threshold voltage deter- mined by the charging energy, electron tunneling via individual quantum

  7. Quantum Dissipative Dynamics of the Magnetic Resonance Force Microscope in the Single-Spin Detection Limit

    E-print Network

    Bruder, Christoph

    -Spin Detection Limit Hanno Gassmann Department of Physics and Astronomy, University of Basel, Klingelbergstrasse cantilever motions. They solved numerically the time-dependent Schr¨odinger equation for the spin-pl

  8. On the design of single electron transistors for the measurement of spins in phosphorus doped silicon

    E-print Network

    Randeria, Mallika

    2012-01-01

    Phosphorus doped silicon is a prime candidate for spin based qubits. We plan to investigate a novel hybrid technique that combines the advantages of spin selective optical excitations with that of electrical readout ...

  9. Spintronic single-qubit gate based on a quantum ring with spin-orbit interaction

    Microsoft Academic Search

    Péter Földi; Balázs Molnár; Mihaly G. Benedict; F. M. Peeters

    2005-01-01

    In a quantum ring connected with two external leads the spin properties of an\\u000aincoming electron are modified by the spin-orbit interaction resulting in a\\u000atransformation of the qubit state carried by the spin. The ring acts as a one\\u000aqubit spintronic quantum gate whose properties can be varied by tuning the\\u000aRashba parameter of the spin-orbit interaction, by changing

  10. 19F and 31P magic-angle spinning nuclear magnetic resonance of antimony(III)-doped fluorapatite phosphors: Dopant sites and spin diffusion

    NASA Astrophysics Data System (ADS)

    Moran, Liam B.; Berkowitz, Jeffery K.; Yesinowski, James P.

    1992-03-01

    Phosphors based on calcium fluorapatite [Ca5F(PO4)3] doped with small amounts of Sb3+ as an activator are used in most fluorescent lamps. We have used quantitative 19F and 31P magic-angle spinning nuclear magnetic resonance (MAS-NMR) to study seven samples of calcium fluorapatite containing 0.0-3.0 wt % Sb3+ in order to determine the site of antimony substitution. The 31P MAS-NMR spectra of fluorapatite containing 3.0, 2.1, and 1.3 wt % antimony contain a single sharp peak at 2.8 ppm indistinguishable from undoped fluorapatite, and show no additional peaks attributable to the influence of antimony. The 31P MAS-NMR spectra of the model compounds SbPO4, Sr1.03Ca8.97F2(PO4)6, Sr5F(PO4)3, and Ba5F(PO4)3 were also obtained. The 19F MAS-NMR spectra of the antimony-doped samples exhibit, in addition to the main peak at 64.0 ppm (downfield from C6F6) arising from unperturbed fluorapatite, a shoulder at 65.6 ppm, and a sharp peak at 68.6 ppm. The measured spin-lattice relaxation times T1 of these antimony-related peaks are equal in all cases to that of the main peak in a given sample, and vary from 129 to 378 sec, indicating that these peaks arise from apatitic fluoride ions perturbed by antimony. Quantitative studies reveal that the 68.6-ppm peak arises from two fluoride ions and the 65.6-ppm shoulder from one fluoride ion per Sb3+ ion incorporated into the lattice. The selective population anti-z and rate of transfer to adjacent nuclei (SPARTAN) pulse sequence used to measure spin diffusion by selectively inverting the 68.6-ppm peak reveals the presence of cross-relaxation to the main peak at 64.0 ppm, but not to the shoulder at 65.6 ppm. Each Sb3+ ion thus appears to be perturbing fluoride ions in at least two different chains. An additional peak at 73.1 ppm observed in some samples is assigned to a second type of antimony(III) substitution, with a single fluoride ion perturbed by each antimony ion. The results in total provide detailed support for a substitution model in which antimony(III) occupies a phosphate site in the apatite lattice, with a SbO3-3 group replacing a PO3-4 group. Two types of substitution at this site appear to occur, depending upon which oxygen atom is replaced by the antimony lone electron pair.

  11. Two methods for nuclear spin determination in collinear laser spectroscopy : classical r.f. magnetic resonance and observation of the Larmor precession (*)

    E-print Network

    Boyer, Edmond

    421 Two methods for nuclear spin determination in collinear laser spectroscopy : classical r. 2014 Measurement of nuclear spin in the collinear laser spectroscopy method has been investigated using]. Recently, the method of collinear laser spectroscopy has shown to be very fruitful in this field [2, 3

  12. Solid state nuclear magnetic resonance with magic-angle spinning and dynamic nuclear polarization below 25 K

    NASA Astrophysics Data System (ADS)

    Thurber, Kent R.; Potapov, Alexey; Yau, Wai-Ming; Tycko, Robert

    2013-01-01

    We describe an apparatus for solid state nuclear magnetic resonance (NMR) with dynamic nuclear polarization (DNP) and magic-angle spinning (MAS) at 20-25 K and 9.4 Tesla. The MAS NMR probe uses helium to cool the sample space and nitrogen gas for MAS drive and bearings, as described earlier [1], but also includes a corrugated waveguide for transmission of microwaves from below the probe to the sample. With a 30 mW circularly polarized microwave source at 264 GHz, MAS at 6.8 kHz, and 21 K sample temperature, greater than 25-fold enhancements of cross-polarized 13C NMR signals are observed in spectra of frozen glycerol/water solutions containing the triradical dopant DOTOPA-TEMPO when microwaves are applied. As demonstrations, we present DNP-enhanced one-dimensional and two-dimensional 13C MAS NMR spectra of frozen solutions of uniformly 13C-labeled L-alanine and melittin, a 26-residue helical peptide that we have synthesized with four uniformly 13C-labeled amino acids.

  13. Solid state nuclear magnetic resonance with magic-angle spinning and dynamic nuclear polarization below 25 K

    PubMed Central

    Thurber, Kent R.; Potapov, Alexey; Yau, Wai-Ming; Tycko, Robert

    2012-01-01

    We describe an apparatus for solid state nuclear magnetic resonance (NMR) with dynamic nuclear polarization (DNP) and magic-angle spinning (MAS) at 20–25 K and 9.4 Tesla. The MAS NMR probe uses helium to cool the sample space and nitrogen gas for MAS drive and bearings, as described earlier (Thurber et al., J. Magn. Reson. 2008) [1], but also includes a corrugated waveguide for transmission of microwaves from below the probe to the sample. With a 30 mW circularly polarized microwave source at 264 GHz, MAS at 6.8 kHz, and 21 K sample temperature, greater than 25-fold enhancements of cross-polarized 13C NMR signals are observed in spectra of frozen glycerol/water solutions containing the triradical dopant DOTOPA-TEMPO when microwaves are applied. As demonstrations, we present DNP-enhanced one-dimensional and two-dimensional 13C MAS NMR spectra of frozen solutions of uniformly 13C-labeled L-alanine and melittin, a 26-residue helical peptide that we have synthesized with four uniformly 13C-labeled amino acids. PMID:23238592

  14. Extracting W Single Spin Asymmetry in Longitudinally Polarized pp Collisions at PHENIX forward arms

    NASA Astrophysics Data System (ADS)

    Meles, Abraham

    2014-09-01

    The parity-violating longitudinal single spin asymmetry AL in the production of W bosons in p + p collisions at ?{ s} = 510 GeV is sensitive to the polarization of light quarks and anti-quarks in the proton. However, identifying the muons from the decay of the W is challenging due to a great background of hadronic processes and other muon producing processes. In the forward and backward hemispheres of PHENIX at RHIC, the muon spectrometers have been recently upgraded in order to provide additional trigger and tracking information to suppress those backgrounds. One of those upgrades is the Forward Vertex (FVTX) detector, a silicon-strip tracker. In 2013, PHENIX collected approximately 240 pb-1 of polarized p + p collisions at ?{ s} = 510 GeV with a beam polarization of 56 %. The ability of the FVTX to improve the W signal will be reviewed, over view of the analysis techniques used to extract the signal from the data in RHIC 2013 run will be discussed. The parity-violating longitudinal single spin asymmetry AL in the production of W bosons in p + p collisions at ?{ s} = 510 GeV is sensitive to the polarization of light quarks and anti-quarks in the proton. However, identifying the muons from the decay of the W is challenging due to a great background of hadronic processes and other muon producing processes. In the forward and backward hemispheres of PHENIX at RHIC, the muon spectrometers have been recently upgraded in order to provide additional trigger and tracking information to suppress those backgrounds. One of those upgrades is the Forward Vertex (FVTX) detector, a silicon-strip tracker. In 2013, PHENIX collected approximately 240 pb-1 of polarized p + p collisions at ?{ s} = 510 GeV with a beam polarization of 56 %. The ability of the FVTX to improve the W signal will be reviewed, over view of the analysis techniques used to extract the signal from the data in RHIC 2013 run will be discussed. Support from US Department of Energy.

  15. Nitrogen nuclear spin flips in nitroxide spin probes of different sizes in glassy o-terphenyl: possible relation with ?- and ?-relaxations.

    PubMed

    Isaev, N P; Dzuba, S A

    2011-09-01

    The pulsed electron-electron double resonance (ELDOR) technique was employed to study nitroxide spin probes of three different sizes dissolved in glassy o-terphenyl. A microwave pulse applied to the central hyperfine structure (hfs) component of the nitroxide electron paramagnetic resonance spectrum was followed by two echo-detecting pulses of different microwave frequency to probe the magnetization transfer (MT) to the low-field hfs component. The MT between hfs components is readily related to flips in the nitrogen nuclear spin, which in turn are induced by molecular motion. The MT on the time scale of tens of microseconds was observed over a wide temperature range, including temperatures near and well below the glass transition. For a bulky nitroxide, it was found that MT rates approach dielectric ? (primary) relaxation frequencies reported for o-terphenyl in the literature. For small nitroxides, MT rates were found to match the frequencies of dielectric ? (secondary) Johari-Goldstein relaxation. The most probable motional mechanism inducing the nitrogen nuclear spin flips is large-angle angular jumps, between some orientations of unequal occupation probabilities. The pulsed ELDOR of nitroxide spin probes may provide additional insight into the nature of Johari-Goldstein relaxation in glassy media and may serve as a tool for studying this relaxation in substances consisting of non-rigid molecules (such as branched polymers) and in heterogeneous and non-polar systems (such as a core of biological membranes). PMID:21913776

  16. Relativistic four-component calculations of indirect nuclear spin-spin couplings with efficient evaluation of the exchange-correlation response kernel

    NASA Astrophysics Data System (ADS)

    K?ístková, Anežka; Komorovsky, Stanislav; Repisky, Michal; Malkin, Vladimir G.; Malkina, Olga L.

    2015-03-01

    In this work, we report on the development and implementation of a new scheme for efficient calculation of indirect nuclear spin-spin couplings in the framework of four-component matrix Dirac-Kohn-Sham approach termed matrix Dirac-Kohn-Sham restricted magnetic balance resolution of identity for J and K, which takes advantage of the previous restricted magnetic balance formalism and the density fitting approach for the rapid evaluation of density functional theory exchange-correlation response kernels. The new approach is aimed to speedup the bottleneck in the solution of the coupled perturbed equations: evaluation of the matrix elements of the kernel of the exchange-correlation potential. The performance of the new scheme has been tested on a representative set of indirect nuclear spin-spin couplings. The obtained results have been compared with the corresponding results of the reference method with traditional evaluation of the exchange-correlation kernel, i.e., without employing the fitted electron densities. Overall good agreement between both methods was observed, though the new approach tends to give values by about 4%-5% higher than the reference method. On the average, the solution of the coupled perturbed equations with the new scheme is about 8.5 times faster compared to the reference method.

  17. Relativistic four-component calculations of indirect nuclear spin-spin couplings with efficient evaluation of the exchange-correlation response kernel.

    PubMed

    K?ístková, Anežka; Komorovsky, Stanislav; Repisky, Michal; Malkin, Vladimir G; Malkina, Olga L

    2015-03-21

    In this work, we report on the development and implementation of a new scheme for efficient calculation of indirect nuclear spin-spin couplings in the framework of four-component matrix Dirac-Kohn-Sham approach termed matrix Dirac-Kohn-Sham restricted magnetic balance resolution of identity for J and K, which takes advantage of the previous restricted magnetic balance formalism and the density fitting approach for the rapid evaluation of density functional theory exchange-correlation response kernels. The new approach is aimed to speedup the bottleneck in the solution of the coupled perturbed equations: evaluation of the matrix elements of the kernel of the exchange-correlation potential. The performance of the new scheme has been tested on a representative set of indirect nuclear spin-spin couplings. The obtained results have been compared with the corresponding results of the reference method with traditional evaluation of the exchange-correlation kernel, i.e., without employing the fitted electron densities. Overall good agreement between both methods was observed, though the new approach tends to give values by about 4%-5% higher than the reference method. On the average, the solution of the coupled perturbed equations with the new scheme is about 8.5 times faster compared to the reference method. PMID:25796226

  18. Electrical control of single hole spins in InSb nanowire quantum dots

    NASA Astrophysics Data System (ADS)

    Pribiag, Vlad; Nadj-Perge, Stevan; van den Berg, Johan; Frolov, Sergey; Plissard, Sebastien; Bakkers, Erik; Kouwenhoven, Leo

    2012-02-01

    The spin-orbit interaction provides an efficient handle for all-electric control of individual spins in quantum dots. Recently, III-V semiconductor nanowires, which have a strong spin-orbit coupling, have emerged as a promising platform for spin-based qubits. Previous work has been focused on the electrical control of electron spins in InAs nanowires. In contrast, spin-dependent quantum transport with holes has so far remained largely unexplored. Here, we demonstrate gate tuning from the few-electron double dot to the few-hole double-dot regimes in InSb nanowires and observe Pauli spin-blockade for both electrons and holes. We use electric-dipole spin resonance (EDSR) to determine the effective g-factors of the two types of carriers. EDSR control over the hole spins is promising for driving coherent rotations of hole-spin qubits. These hole qubits are expected to be less sensitive to hyperfine-mediated decoherence effects than electron-spin qubits as a result of the p-wave symmetry of the hole wavefunction.

  19. Spin Technologies in Silicon Carbide

    NASA Astrophysics Data System (ADS)

    Klimov, Paul

    2015-03-01

    Over the past several decades SiC has evolved from being a simple abrasive to a versatile material platform for high-power electronics, optoelectronics, and nanomechanical devices. These technologies have been driven by advanced growth, doping, and processing capabilities, and the ready availability of large-area, single-crystal SiC wafers. Recent advances have also established SiC as a promising host for a novel class of technologies based on the spin of intrinsic color centers. In particular, the divacancies and related defects have ground-state electronic-spin triplets with ms-long coherence times that can be optically addressed near telecom wavelengths and manipulated with magnetic, electric, and strain fields. Recently, divacancy addressability has been extended to the single defect level, laying foundation for single spin technologies in SiC. This rapidly developing field has prompted research into the SiC material host to understand how defect-bound electron spins interact with their surrounding nuclear spin bath. Although nuclear spins are typically a major source of decoherence in color-center spin systems, they are also an important resource since they interact with magnetic fields orders of magnitude more weakly than electronic spins. This fact has motivated their use for quantum memories and ultra-sensitive sensors. In this talk I will review advances in this rapidly developing field and discuss our efforts towards this latter goal. This work was supported by the AFOSR, DARPA, and the NSF.

  20. Electronegativities and isoelectronic energy and electronegativity differences for monatomic systems with nonintegral nuclear charges: Local-spin-density-functional calculations

    Microsoft Academic Search

    K. D. Sen; Jorge M. Seminario; Peter Politzer

    1989-01-01

    A relativistic self-consistent-field self-interaction-corrected local-spin-density functional, with electronic correlation included, has been used to compute the electronegativities of monatomic systems with nonintegral nuclear charges. We focused specifically upon quark atoms related to the halogens, having nuclear charges of Z+\\/-1\\/3. Two different methods for calculating electronegativities were found to give results in good agreement with each other and with an earlier

  1. Nuclear Spin of H_3^+ and H_2 in Dense Molecular Clouds

    NASA Astrophysics Data System (ADS)

    Crabtree, Kyle N.; McCall, Benjamin J.

    2012-06-01

    The ortho:para ratio of H_2 is a critical parameter for deuterium fractionation in cold, dense quiescent cores. The dominant reservoir for interstellar deuterium is in the inert molecule HD, but the exothermic reaction H_3^+ + HD ? H_2D^+ + H_2 + 220 K (and H_2D^+ + HD, etc.) can yield highly reactive species capable of distributing deuterium to other molecules. The barrier to the reverse reaction, however, can be overcome even at temperatures below 10 K when ortho-H_2 (o-H_2) reacts with H_2D^+ (or D_2H^+, D_3^+), as ortho-H_2 possesses ˜170 K of internal rotational energy in its ground state. Recent modeling work has demonstrated the importance of o-H_2 in cold, dense, highly depleted cores using a chemical network that includes all nuclear spin modifications of H_3^+, H_2, and their isotopologues, but the initial o-H_2 fraction is taken as a parameter in the model. Observationally or computationally constraining this quantity would aid in understanding deuterium fractionation in dense cores. To learn about the initial o-H_2 fraction in a cold core, we have modeled the chemistry of non-depleted dense interstellar clouds from which cold cores are thought to form. A simplified gas-phase chemical network consisting of 28 species and ˜170 reactions is combined with a physical model of a dense cloud, including time-dependent physical conditions. Included in the network are the nuclear spin modifications of H_2, H_2^+, and H_3^+, as well as nuclear spin dependent rate coefficients for the thermalization reactions H_2 + H^+ and H_3^+ + H_2. By modeling the time-dependent chemistry, we find that the ortho:para ratio of H_2 requires 10^7-10^8 years to reach steady state under ``standard'' dense cloud conditions, which is at least on the order of the cloud lifetime. The timescale depends on the ionization rate, the rate coefficients of the various H_3^+ + H_2 reactions, and the relative abundances of H_3^+ and H^+, but is largely insensitive to the total density and temperature. Even at steady state, the o-H_2 fraction is calculated to be >0.5% at 10 K, which is several orders of magnitude above its value at thermodynamic equilibrium. The prospects for using observations of the ortho:para ratio of H_3^+ as a probe of the H_2 ortho:para ratio will be discussed.

  2. Optical Pumping and Electron Spin Resonance of Single 87Rb Atoms on Helium Nanodroplets

    NASA Astrophysics Data System (ADS)

    Koch, Markus; Poms, Johannes; Volk, Alexander; Ernst, Wolfgang E.

    2011-06-01

    Our recent development of electron spin resonance (ESR) spectroscopy on superfluid helium nanodroplets (HeN) provides a sensitive tool to investigate interactions between a surface located alkali-metal atom and an ESR silent species inside the droplet. Highest sensitivity is expected for alkali-metal atoms with large hyperfine coupling. We present hyperfine resolved ESR spectra of single 87Rb (hyperfine constant a_HFS = 3417 MHz) atoms isolated on HeN. In accordance with our previous work on 85Rb (AHFS= 1012 MHz) we find a droplet size dependent increase of AHFS between 400 and 450 ppm, due to the electronic perturbation by the helium environment. The process of optical pumping and of optical detection on HeN is investigated in detail in order to optimize the ESR signal. A simple model for optical pumping on HeN is presented, which agrees well with the experimental results. M. Koch, G. Auböck, C. Callegari, and W.E. Ernst, Phys. Rev. Lett. 103, 035302 (2009) A. Volk, J. Poms, M. Koch, and W.E. Ernst, J. Phys. Chem. A, in press

  3. Beam Normal Single Spin Asymmetry in the N-to-Delta Transition

    NASA Astrophysics Data System (ADS)

    Nuruzzaman, Nuruzzaman; Qweak Collaboration

    2013-10-01

    The Q-weak experiment in Hall C at the Thomas Jefferson National Accelerator Facility has made the first direct measurement of the weak charge of the proton, QWp,through the precision measurement of the parity-violating (PV) asymmetry in elastic e-p scattering at low momentum transfer. The data are currently under analysis. There is a parity conserving Beam Normal Single Spin Asymmetry or transverse asymmetry (An) on H2 with a sin(?) -like dependence due to 2- ? exchange. The size of An is few ppm, so a few percent residual transverse polarization in the beam, in addition to potentially small broken azimuthal symmetries in the detector, might lead to few ppb corrections to the Q-weak data. As part of a program of An background studies, we made the first measurement of An in the N-to-Delta transition using the Q-weak apparatus. An from electron-nucleon scattering is also a unique tool to study the ?* ?? form factors. Status of the analysis will be presented. Supported in part by the Department of Energy and the National Science Foundation

  4. Most spin-1/2 transition-metal ions do have single ion anisotropy.

    PubMed

    Liu, Jia; Koo, Hyun-Joo; Xiang, Hongjun; Kremer, Reinhard K; Whangbo, Myung-Hwan

    2014-09-28

    The cause for the preferred spin orientation in magnetic systems containing spin-1/2 transition-metal ions was explored by studying the origin of the easy-plane anisotropy of the spin-1/2 Cu(2+) ions in CuCl2·2H2O, LiCuVO4, CuCl2, and CuBr2 on the basis of density functional theory and magnetic dipole-dipole energy calculations as well as a perturbation theory treatment of the spin-orbit coupling. We find that the spin orientation observed for these spin-1/2 ions is not caused by their anisotropic spin exchange interactions, nor by their magnetic dipole-dipole interactions, but by the spin-orbit coupling associated with their crystal-field split d-states. Our study also predicts in-plane anisotropy for the Cu(2+) ions of Bi2CuO4 and Li2CuO2. The results of our investigations dispel the mistaken belief that magnetic systems with spin-1/2 ions have no magnetic anisotropy induced by spin-orbit coupling. PMID:25273418

  5. Most spin-1/2 transition-metal ions do have single ion anisotropy

    SciTech Connect

    Liu, Jia; Whangbo, Myung-Hwan, E-mail: hxiang@fudan.edu.cn, E-mail: mike-whangbo@ncsu.edu [Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695 (United States); Koo, Hyun-Joo [Department of Chemistry and Research Institute for Basic Sciences, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Xiang, Hongjun, E-mail: hxiang@fudan.edu.cn, E-mail: mike-whangbo@ncsu.edu [Key Laboratory of Computational Physical Sciences (Ministry of Education), State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai 200433 (China); Kremer, Reinhard K. [Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart (Germany)

    2014-09-28

    The cause for the preferred spin orientation in magnetic systems containing spin-1/2 transition-metal ions was explored by studying the origin of the easy-plane anisotropy of the spin-1/2 Cu{sup 2+} ions in CuCl{sub 2}·2H{sub 2}O, LiCuVO{sub 4}, CuCl{sub 2}, and CuBr{sub 2} on the basis of density functional theory and magnetic dipole-dipole energy calculations as well as a perturbation theory treatment of the spin-orbit coupling. We find that the spin orientation observed for these spin-1/2 ions is not caused by their anisotropic spin exchange interactions, nor by their magnetic dipole-dipole interactions, but by the spin-orbit coupling associated with their crystal-field split d-states. Our study also predicts in-plane anisotropy for the Cu{sup 2+} ions of Bi{sub 2}CuO{sub 4} and Li{sub 2}CuO{sub 2}. The results of our investigations dispel the mistaken belief that magnetic systems with spin-1/2 ions have no magnetic anisotropy induced by spin-orbit coupling.

  6. Mercuric iodide single crystals for nuclear radiation detectors

    Microsoft Academic Search

    Weitang Li; Zhenghui Li; Shifu Zhu; Shujun Yin; Beijun Zhao; Guanxiong Chen; Shi Yin; Hong Yuan; Huapeng Xu

    1996-01-01

    Large size HgI2 single crystals were grown using the modified temperature oscillation method with low dislocation densities in a relatively stable temperature environment. Radiation detectors were fabricated from the single crystals which showed good energy resolution with small polarization

  7. Mercuric iodide single crystal for nuclear radiation detectors

    Microsoft Academic Search

    Weitang Li; Zhenghui Li; Shifu Zhu; Shujun Yin; Beijun Zhao; Guanxiong Chen; Shi Yin; Hong Yuan; Huapeng Xu

    1995-01-01

    Large size HgI2 single crystals are grown using the modified temperature oscillation method with low dislocation densities in a relatively stable temperature environment. Radiation detectors are fabricated from the single crystals which show good energy resolution with small polarization

  8. Mercuric iodide single crystals for nuclear radiation detectors

    SciTech Connect

    Li, W.; Li, Z.; Zhu, S.; Yin, S.; Zhao, B.; Chen, G. [Sichuan Univ., Chengdu (China). Material Science Dept.; Yin, S. [Univ. of Southern California, Los Angeles, CA (United States). Physics Dept.; Yuan, H.; Xu, H. [Deyang Mercuric Iodide Single Crystal Plant, Sichuan (China)

    1996-06-01

    Large size HgI{sub 2} single crystals were grown using the Modified Temperature Oscillation Method (MTOM) with low dislocation densities in a relatively stable temperature environment. Radiation detectors were fabricated from the single crystals which showed good energy resolution with small polarization. Applications have been found in geological explorations, marine mineral analysis, environment pollution monitoring, industrial material quality assurance, and space explorations.

  9. Pulsed and continuous wave electron nuclear double resonance patterns of aquo protons coordinated in frozen solution to high spin MN2 +

    NASA Astrophysics Data System (ADS)

    Tan, Xiaoling; Bernardo, Marcelino; Thomann, Hans; Scholes, Charles P.

    1993-04-01

    For the water protons that coordinate to Mn2+, the frozen solution ENDOR (electron nuclear double resonance) spectra are made complex by the anisotropic electron-proton hyperfine interaction and by multiple contributions of the electron spin 5/2 manifold. A spin 5/2 Mn2+ ion having magnetic quantum numbers Ms=±1/2, ±3/2, ±5/2 and small zero-field splittings has overlapping electron spin EPR transitions. Proton hyperfine couplings to each of these electron spin states have yielded overlapping ENDOR patterns whose interpretation is nontrivial, even in so simple a system as Mn2+ ion having hexaaquo coordination. We have experimentally obtained and theoretically explained these proton ENDOR patterns and in so doing have laid the foundation for interpreting and sorting out frozen solution ENDOR patterns in more complex (enzyme) environments. Pulsed and cw ENDOR experiments showed features of metal-coordinated water protons occurring not only within a few MHz of the free proton frequency (as will happen for an electron spin 1/2 system) but extending over a range of up to 35 MHz. The EPR line of the Mn2+ S=5/2 manifold was broadened by zero-field splitting for hundreds of Gauss away from g=2.00, and the relative intensity of different ENDOR features reflected couplings to differing Ms spin states at varying fields across this EPR line. An expression was derived to show the dependence of proton ENDOR frequencies on the electron spin quantum number, Ms, upon the principal values of the intrinsic proton hyperfine tensor, upon the direction of the magnetic field, and upon the free proton frequency. This expression provided the starting point for powder simulations of the overall ENDOR pattern. These ENDOR powder pattern simulations were not elementary extensions of first-order theory as often applied to single-crystallike ENDOR spectra obtained at frozen solution EPR extrema. These simulations addressed the interpretation and the conditions for obtaining consistent hyperfine information from nuclei hyperfine coupled to Mn2+ where all Ms levels of the Mn2+ ion can furnish contributions to ENDOR and EPR. The aquo protons yielded an isotropic coupling As=0.8 MHz and a dipolar coupling Ad=3.4 MHz, where A?=2Ad+As (=7.6 MHz) and A?=As-Ad (=-2.6 MHz). Such couplings are in agreement with those obtained by proton ENDOR of [Mn(H2O)6]2+ in single crystals [R. DeBeer, W. DeBoer, C. A. Van't Hof, and D. Van Ormondt, Acta Cryst. B29, 1473 (1973)].

  10. Interfacial spin-glass-like state in Mn5Ge3 single crystalline films grown on germanium substrates

    NASA Astrophysics Data System (ADS)

    Truong, A.; Watanabe, A. O.; Mortemousque, P. A.; Ando, K.; Sato, T.; Taniyama, T.; Itoh, K. M.

    2015-06-01

    Thermal irreversibility of the magnetization in Mn5Ge3 epitaxial thin films on Ge(111) is reported. The frequency dependence of the ac susceptibility demonstrates a spin-glass-like behavior, despite the fact that the thin film is a single crystal. Such glassy behavior is attributed to the presence of a "ferromagnetically dead" layer with spin-glass-like properties at the Mn5Ge3/Ge interface, which results in frustrated interactions with the ferromagnetic Mn5Ge3 . Moreover, it is shown that the magnetic phase diagram in the H -T plane of the glassy state is very sensitive to the growth conditions. Variation in the growth temperature and film thickness changes the spin-glass-like properties and the Curie temperature. The sensitivity of the glassy state to the growth conditions is related to the variation in the properties of the interfacial layer.

  11. Single spin-torque vortex oscillator using combined bottom-up approach and e-beam lithography

    NASA Astrophysics Data System (ADS)

    Abreu Araujo, F.; Piraux, L.; Antohe, V. A.; Cros, V.; Gence, L.

    2013-06-01

    A combined bottom-up assembly of electrodeposited nanowires and electron beam lithography technique has been developed to investigate the spin transfer torque and microwave emission on specially designed nanowires containing a single Co/Cu/Co pseudo spin valve. Microwave signals have been obtained even at zero magnetic field. Interestingly, high frequency vs. magnetic field tunability was demonstrated, in the range 0.4-2 MHz/Oe, depending on the orientation of the applied magnetic field relative to the magnetic layers of the pseudo spin valve. The frequency values and the emitted signal frequency as a function of the external magnetic field are in good quantitative agreement with the analytical vortex model as well as with micromagnetic simulations.

  12. Giant titanium electron wave function in gallium oxide: A potential electron-nuclear spin system for quantum information processing

    NASA Astrophysics Data System (ADS)

    Mentink-Vigier, Frédéric; Binet, Laurent; Vignoles, Gerard; Gourier, Didier; Vezin, Hervé

    2010-11-01

    The hyperfine interactions of the unpaired electron with eight surrounding G69a and G71a nuclei in Ti-doped ?-Ga2O3 were analyzed by electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) spectroscopies. They are dominated by strong isotropic hyperfine couplings due to a direct Fermi contact interaction with Ga nuclei in octahedral sites of rutile-type chains oriented along b axis, revealing a large anisotropic spatial extension of the electron wave function. Titanium in ?-Ga2O3 is thus best described as a diffuse (Ti4+-e-) pair rather than as a localized Ti3+ . Both electron and G69a nuclear spin Rabi oscillations could be observed by pulsed EPR and pulsed ENDOR, respectively. The electron spin decoherence time is about 1?s (at 4 K) and an upper bound of 520?s (at 8 K) is estimated for the nuclear decoherence time. Thus, ?-Ga2O3:Ti appears to be a potential spin-bus system for quantum information processing with a large nuclear spin quantum register.

  13. 23Na Nuclear Spin-Lattice Relaxation Studies of Na2Ni2TeO6

    NASA Astrophysics Data System (ADS)

    Itoh, Yutaka

    2015-06-01

    We report on 23Na NMR studies of the honeycomb lattice antiferromagnet Na2Ni2TeO6 by 23Na nuclear spin-echo techniques. The 23Na nuclear spin-lattice relaxation rate 1/23T1 exhibits critical divergence near the Néel temperature TN = 26 K, a narrow critical region, and the critical exponent w = 0.34 in 1/23T1 ? (T/TN - 1)-w for Na2Ni2TeO6, and TN = 18 K for Na2(Ni0.5Cu0.5)2TeO6. Although the uniform magnetic susceptibility of Na2Ni2TeO6 exhibits a broad maximum at 35 K, which is the characteristic of low-dimensional spin systems, the NMR results indicate a three-dimensional criticalphenomenon near the Néel temperature.

  14. The Low-temperature Nuclear Spin Equilibrium of H+ 3 in Collisions with H2

    NASA Astrophysics Data System (ADS)

    Grussie, F.; Berg, M. H.; Crabtree, K. N.; Gärtner, S.; McCall, B. J.; Schlemmer, S.; Wolf, A.; Kreckel, H.

    2012-11-01

    Recent observations of H2 and H+ 3 in diffuse interstellar sightlines revealed a difference in the nuclear spin excitation temperatures of the two species. This discrepancy comes as a surprise, as H+ 3 and H2 should undergo frequent thermalizing collisions in molecular clouds. Non-thermal behavior of the fundamental H+ 3/H2 collision system at low temperatures was considered as a possible cause for the observed irregular populations. Here, we present measurements of the steady-state ortho/para ratio of H+ 3 in collisions with H2 molecules in a temperature-variable radiofrequency ion trap between 45 and 100 K. The experimental results are close to the expected thermal outcome and they agree very well with a previous micro-canonical model. We briefly discuss the implications of the experimental results for the chemistry of the diffuse interstellar medium.

  15. Investigation of ion beam deposited spin valve interface structure by 59Co nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    JÈ©dryka, Ewa; Bailey, William E.; Wójcik, Marek; Nadolski, Stefan; Wang, Shan X.

    1999-04-01

    59Co nuclear magnetic resonance was used to study the bulk and interface microstructure in the unpinned Co layer in a series of highly (111)-textured ion beam deposited spin valves. The intent of the study is to determine the degree of Co interface intermixing and any possible variation of the Co layer microstructure as a result of weakening (111) texture of the NiFe/Co/Cu/Co/NiFe/FeMn film stack. We found that the interfaces are diffused over ˜2 monolayers on both sides of the Co layer, involving an equivalent of about 3 Å of Co per interface and vary only slightly with deteriorating texture. The main structural change is the drop of perfect fcc stacking in the Co layer.

  16. Scalable Quantum Computing based on Spin Qubits in CNT QD

    E-print Network

    Stobi?ska, Magdalena; Stobi?ski, Leszek

    2009-01-01

    We study experimentally demonstrated single-electron ${}^{12}$C CNT QD with significant spin-orbit interaction as a scalable quantum computer candidate. Both electron spin and orbital angular momentum can serve as a logical qubit for quantum processing. We introduce macroscopic quantum memory for the system in a form of injected either magnetic or spin carrying atomic ensemble into the nanotube. CNT provides with a stable atomic trap in finite temperature and with one-dimensional nuclear spin lattice in an external magnetic field. The electron is coupled to the atomic ensemble through either magnetic or hyperfine interaction. Easy electron and nuclear spin read-out procedure for this system is possible.

  17. Scalable Quantum Computing based on Spin Qubits in CNT QD

    E-print Network

    Magdalena Stobi?ska; Gerard J. Milburn; Leszek Stobi?ski

    2009-12-17

    We study experimentally demonstrated single-electron ${}^{12}$C CNT QD with significant spin-orbit interaction as a scalable quantum computer candidate. Both electron spin and orbital angular momentum can serve as a logical qubit for quantum processing. We introduce macroscopic quantum memory for the system in a form of injected either magnetic or spin carrying atomic ensemble into the nanotube. CNT provides with a stable atomic trap in finite temperature and with one-dimensional nuclear spin lattice in an external magnetic field. The electron is coupled to the atomic ensemble through either magnetic or hyperfine interaction. Easy electron and nuclear spin read-out procedure for this system is possible.

  18. Nuclear spin relaxation of {sup 129}Xe due to persistent xenon dimers

    SciTech Connect

    Berry-Pusey, B. N.; Anger, B. C.; Laicher, G.; Saam, B. [Department of Physics, University of Utah, Salt Lake City, Utah 84112-0830 (United States)

    2006-12-15

    We have measured longitudinal nuclear relaxation rates of {sup 129}Xe in Xe-N{sub 2} mixtures at densities below 0.5 amagats in a magnetic field of 8.0 T. We find that intrinsic spin relaxation in this regime is principally due to fluctuations in the intramolecular spin-rotation (SR) and chemical-shift-anisotropy (CSA) interactions, mediated by the formation of {sup 129}Xe-Xe persistent dimers. Our results are consistent with previous work done in one case at much lower applied fields where the CSA interaction is negligible and in another case at much higher gas densities where transient xenon dimers mediate the interactions. We have verified that a large applied field suppresses the persistent-dimer mechanism, consistent with standard relaxation theory, allowing us to measure room-temperature gas-phase relaxation times T{sub 1} for {sup 129}Xe greater than 25 h at 8.0 T. These data also yield a maximum possible low-field T{sub 1} for pure xenon gas at room temperature of 5.45{+-}0.2 h. The coupling strengths for the SR and CSA interactions that we extract are in fair agreement with estimates based both on previous experimental work and on ab initio calculations. Our results have potential implications for the production and storage of large quantities of hyperpolarized {sup 129}Xe for use in various applications.

  19. Hyperpolarization of 29Si by Resonant Nuclear Spin Transfer from Optically Hyperpolarized 31P Donors

    NASA Astrophysics Data System (ADS)

    Dluhy, Phillip; Salvail, Jeff; Saeedi, Kamyar; Thewalt, Mike; Simons, Stephanie

    2014-03-01

    Recent developments in nanomedicine have allowed nanoparticles of silicon containing hyperpolarized 29Si to be imaged in vivo using magnetic resonance imaging. The extremely long relaxation times and isotropy of the Si lattice make polarized 29Si isotopes ideal for these sorts of imaging methods. However, one of the major difficulties standing in the path of widespread adoption of these techniques is the slow rate at which the 29Si is hyperpolarized and the limited maximum hyperpolarization achievable. In this talk, I will describe an effective method for hyperpolarization of the 29Si isotopes using resonant optical pumping of the donor bound exciton transitions to polarize the 31P donor nuclei, and a choice of static magnetic field that conserves energy during spin flip flops between donor nuclear and 29Si spins to facilitate diffusion of this polarization. Using this method, we are able to polarize greater than 10% of the 29Si centers in 64 hours without seeing saturation of the 29Si polarization.

  20. The importance of strain on spin-spin coupling in Pr5/8Ca3/8MnO3 single crystal film

    SciTech Connect

    Fu, Xinwen [Shanghai University, Shanghai, Peoples R China; Gao, Yuze [Max-Planck-Institute for Solid State Research, Stuttgart, Germany; Wu, Zhiwei [Shanghai University, Shanghai, Peoples R China; Zhang, Jincang [Shanghai University, Shanghai, Peoples R China; Li, Qing [ORNL; Cao, Guixin [ORNL

    2012-01-01

    The influence of anisotropic strains on coupling spins is systematically investigated in pulsed laser deposited single crystal Pr5/8Ca3/8MnO3 film. The substrate was chosen to introduce tensile and compressive strain onto the film. Various experiments, i.e., zero field cooled/field cooled (ZFC/FC) magnetization measurement, hysteresis loops, and exchange bias field detection, have revealed distinct difference along two perpendicular in-plane axes which represent tensile and compressive strain orientation, respectively. We found that the observed phenomenon can be explained by the external strain effect.