Rotating Superconductors and the Frame-independent London Equation

A frame-independent, thermodynamically exact London equation is presented, which is especially valid for rotating superconductors. A direct result is the unexpectedly high accuracy ($\sim10^{-10}$) for the usual expression of the London moment.Comment: 4 pages, 0 figure

Mass estimate of the Swift J 164449.3+573451 supermassive black hole based on the 3:2 QPO resonance hypothesis

A dormant Swift source J 164449.3+573451 (Sw 164449+57)recently experienced a powerful outburst, caused most probably by a tidal disruption of a star by the super-massive black hole at the center of the source. During the outburst, a quasi periodic oscillation (QPO) was detected in the observed X-ray flux from Sw 164449+57. We show that if the observed QPO belongs to a "3:2 twin peak QPO" (with the second frequency not observed), the mass of the black hole in Sw 164449+57 is rather low, M ~ 10^5 M_sun, and the source belongs to a class of intermediate mass black holes. The low mass of the source has been pointed out previously by several authors.Comment: Accepted by Astronomy and Astrophysic

Massive Fields of Arbitrary Integer Spin in Symmetrical Einstein Space

We study the propagation of gauge fields with arbitrary integer spins in the symmetrical Einstein space of any dimensionality. We reduce the problem of obtaining a gauge-invariant Lagrangian of integer spin fields in such background to an purely algebraic problem of finding a set of operators with certain features using the representation of high-spin fields in the form of some vectors of pseudo-Hilbert space. We consider such construction in the linear order in the Riemann tensor and scalar curvature and also present an explicit form of interaction Lagrangians and gauge transformations for massive particles with spins 1 and 2 in terms of symmetrical tensor fields.Comment: 15 pages, latex, no figures,minor change

Particle Entanglement in Rotating Gases

In this paper, we investigate the particle entanglement in 2D weakly-interacting rotating Bose and Fermi gases. We find that both particle localization and vortex localization can be indicated by particle entanglement. We also use particle entanglement to show the occurrence of edge reconstruction of rotating fermions. The different properties of condensate phase and vortex liquid phase of bosons can be reflected by particle entanglement and in vortex liquid phase we construct a trial wave function in the viewpoint of entanglement to relate the ground state with quantum Hall state. Finally, the relation between particle entanglement and interaction strength is studied.Comment: 7 pages, 9 figure

Quantum quench dynamics of the Bose-Hubbard model at finite temperatures

We study quench dynamics of the Bose-Hubbard model by exact diagonalization. Initially the system is at thermal equilibrium and of a finite temperature. The system is then quenched by changing the on-site interaction strength $U$ suddenly. Both the single-quench and double-quench scenarios are considered. In the former case, the time-averaged density matrix and the real-time evolution are investigated. It is found that though the system thermalizes only in a very narrow range of the quenched value of $U$, it does equilibrate or relax well in a much larger range. Most importantly, it is proven that this is guaranteed for some typical observables in the thermodynamic limit. In order to test whether it is possible to distinguish the unitarily evolving density matrix from the time-averaged (thus time-independent), fully decoherenced density matrix, a second quench is considered. It turns out that the answer is affirmative or negative according to the intermediate value of $U$ is zero or not.Comment: preprint, 20 pages, 7 figure

The Dynamics of the Bounds of Squared Concurrence

We study the dynamics of upper and lower bounds of squared concurrence.Our results are similar to that of Konard et al. and can help the estimation of high-dimension bipartite entanglement in experiments.Comment: 5 pages, 2 figures accepted by PR

The Decay of Multiqudit Entanglement

We investigate the decay of entanglement of a generalized N-qudit GHZ state, with each qudit passing through independently in a quantum noisy channel. By studying the time at which the entanglement completely vanishes and the time at which the entanglement becomes arbitrarily small, we try to find how the robustness of entanglement is influenced by dimension d and the number of particles N.Comment: 4 pages, 3 figure