1,194,152 research outputs found

    Entanglement sudden death in qubit-qutrit systems

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    We demonstrate the existence of entanglement sudden death (ESD), the complete loss of entanglement in finite time, in qubit-qutrit systems. In particular, ESD is shown to occur in such systems initially prepared in a one-parameter class of entangled mixed states and then subjected to local dephasing noise. Together with previous results, this proves the existence of ESD for some states in all quantum systems for which rigorously defined mixed-state entanglement measures have been identified. We conjecture that ESD exists in all quantum systems prepared in appropriate bipartite states.Comment: 10 pages. To appear in Physics Letters

    Influence of Cooper pairing on the inelastic processes in a gas of Fermi atoms

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    Correlation properties in ultracold Fermi gas with negative scattering length and its impact on the three-body recombination is analyzed. We find that Cooper pairing enhances the recombination rate in contrast to the decrease of this rate accompanying Bose-Einstein condensation in a Bose gas. This trend is characteristic for all interval of temperatures T<Tc

    Dual versions of N=2 supergravity and spontaneous supersymmetry breaking

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    In this paper, using a model of N=2 supergravity - vector multiplets interaction with the scalar field geometry SU(1,m)/SU(m)U(1)SU(1,m)/SU(m)\otimes U(1) as an example, we show that even when the geometry is fixed one can have a whole family of the Lagrangians that differ by the vector field duality transformations. As a byproduct, for this geometry we have constructed a model of (m-1) vector multiplets interacting with the hidden sector admitting spontaneous supersymmetry breaking with two arbitrary scales and without a cosmological term.Comment: 10 pages, LaTeX, IHEP preprint 94-9

    General covariance violation and the gravitational dark matter. II. Vector graviton

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    The (four componenet) vector graviton contained in metric, the scalar component incorporated, is attributed to the violation of the general covariance to the residual isoharmonic one. In addition to the previously studied (singlet) scalar graviton, the vector graviton may constitute one more fraction of the gravitational dark matter. The gravity interactions of the vector graviton, as well as its impact on the continuous medium are studied.Comment: 10 page