32,915 research outputs found

    Production of entanglement with highly-mixed states

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    We study production of entanglement with highly-mixed states. We find that entanglement between highly mixed states can be generated via a direct unitary interaction even when both states have purities arbitrarily close to zero. This indicates that purity of a subsystem is not required for entanglement generation. Our result is in contrast to previous studies where the importance of the subsystem purity was emphasized.Comment: 4 pages, 5 figure

    Crystal bases for the quantum queer superalgebra

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    Correlation Assisted Phonon Softenings and the Mott-Peierls Transition in VO2_{2}

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    To explore the driving mechanisms of the metal-insulator transition (MIT) and the structural transition in VO2, we have investigated phonon dispersions of rutile VO2 (R-VO2) in the DFT and the DFT+U (U : Coulomb correlation) band calculations. We have found that the phonon softening instabilities occur in both cases, but the softened phonon mode only in the DFT+U describes properly both the MIT and the structural transition from R-VO2 to monoclinic VO2 (M1-VO2). This feature demonstrates that the Coulomb correlation effect plays an essential role of assisting the Peierls transition in R-VO2. We have also found from the phonon dispersion of M1-VO2 that M1 structure becomes unstable under high pressure. We have predicted a new phase of VO2 at high pressure that has a monoclinic CaCl2-type structure with metallic nature

    Prescribing for adolescents

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    © 2019 NPS MedicineWise. The process of prescribing changes as children move into adulthood. For some medicines, such as psychotropic drugs, safety and efficacy are less well understood in adolescents. As adolescents mature they attain the capacity to consent to their own medical treatment. An assessment of their competency will need to take into account the nature of the treatment being proposed. Parental involvement is usually beneficial particularly for adolescents with chronic or complex conditions, but increasing adolescent autonomy needs to be respected. Adherence to treatment can be supported by understanding adolescent development and involving adolescents in management plans

    Time dependent CP asymmetry in B0ρ0γB^0 \to \rho^0 \gamma decay to probe the origin of CP violation

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    Since the CP violation in the BB system has been investigated up to now only through processes related to the BB--Bˉ\bar{B} mixing, urgently required is new way of study for the CP violation and establishing its origin in the BB system independent of the mixing process. In this work, we explore the exclusive B0ρ0γ B^0 \to \rho^0 \gamma decay to obtain the time-dependent CP asymmetry in bdb \to d decay process in the standard model and the supersymmetric model. We find that the complex RL and RR mass insertion to the squark sector in the MSSM can lead to a large CP asymmetry in bdγb \to d \gamma decay through the gluino-squark diagrams, which is not predicted in the Standard Model induced by the BB--Bˉ\bar{B} mixing.Comment: 10 pages, 4 eps figure

    Some Grüss' Type Inequalities in 2-Inner Product Spaces and Applications for Determinantal Integral Inequalities

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    Some new Grüss type inequalities in 2-inner product spaces are given. Using this framework, some determinantal integral inequalities for synchronous functions are also derived

    Magneto-optics in pure and defective Ga_{1-x}Mn_xAs from first-principles

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    The magneto-optical properties of Ga1x_{1-x}Mnx_{x}As including their most common defects were investigated with precise first--principles density-functional FLAPW calculations in order to: {\em i}) elucidate the origin of the features in the Kerr spectra in terms of the underlying electronic structure; {\em ii}) perform an accurate comparison with experiments; and {\em iii}) understand the role of the Mn concentration and occupied sites in shaping the spectra. In the substitutional case, our results show that most of the features have an interband origin and are only slightly affected by Drude--like contributions, even at low photon energies. While not strongly affected by the Mn concentration for the intermediately diluted range (xx\sim 10%), the Kerr factor shows a marked minimum (up to 1.5o^o) occurring at a photon energy of \sim 0.5 eV. For interstitial Mn, the calculated results bear a striking resemblance to the experimental spectra, pointing to the comparison between simulated and experimental Kerr angles as a valid tool to distinguish different defects in the diluted magnetic semiconductors framework.Comment: 10 pages including 2 figures, submitted to Phys. Rev.

    Temperature- and magnetic-field-dependent resistivity of MgB2 sintered at high temperature and high pressure condition

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    We report the temperature- and magnetic-field-dependent resistivity of MgB2 sintered at high temperature and high pressure condition. The superconducting transition width for the resistivity measurement was about 0.4 K, and the low-field magnetization showed a sharp superconducting transition with a transition width of about 1 K. The resistivity in the normal state roughly followed T^2 behavior with smaller residual resistivity ratio (RRR) of 3 over broad temperature region above 100 K rather than reported T^3 behavior with larger RRR value of ~ 20 in the samples made at lower pressures. Also, the resistivity did not change appreciably with the applied magnetic field, which was different from previous report. These differences were discussed with the microscopic and structural change due to the high-pressure sintering.Comment: 2 pages, 3 figures. Accepted by Physica

    Defect Motion and Lattice Pinning Barrier in Josephson-Junction Ladders

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    We study motion of domain wall defects in a fully frustrated Josephson-unction ladder system, driven by small applied currents. For small system sizes, the energy barrier E_B to the defect motion is computed analytically via symmetry and topological considerations. More generally, we perform numerical simulations directly on the equations of motion, based on the resistively-shunted junction model, to study the dynamics of defects, varying the system size. Coherent motion of domain walls is observed for large system sizes. In the thermodynamical limit, we find E_B=0.1827 in units of the Josephson coupling energy.Comment: 7 pages, and to apear in Phys. Rev.
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