85 research outputs found
Wigner function for damped systems
Both classical and quantum damped systems give rise to complex spectra and
corresponding resonant states. We investigate how resonant states, which do not
belong to the Hilbert space, fit the phase space formulation of quantum
mechanics. It turns out that one may construct out of a pair of resonant states
an analog of the stationary Wigner function.Comment: 18 page
A class of Bell diagonal states and entanglement witnesses
We analyze special class of bipartite states - so called Bell diagonal
states. In particular we provide new examples of bound entangled Bell diagonal
states and construct the class of entanglement witnesses diagonal in the magic
basis.Comment: 17 page
Bounds on the entanglement of two-qutrit systems from fixed marginals
We discuss the problem of characterizing upper bounds on entanglement in a bipartite quantum system when only the reduced density matrices (marginals) are known. In particular, starting from the known two-qubit case, we propose a family of candidates for maximally entangled mixed states with respect to fixed marginals for two qutrits. These states are extremal in the convex set of two-qutrit states with fixed marginals. Moreover, it is shown that they are always quasidistillable. As a by-product we prove that any maximally correlated state that is quasidistillable must be pure. Our observations for two qutrits are supported by numerical analysis
A class of commutative dynamics of open quantum systems
We analyze a class of dynamics of open quantum systems which is governed by
the dynamical map mutually commuting at different times. Such evolution may be
effectively described via spectral analysis of the corresponding time dependent
generators. We consider both Markovian and non-Markovian cases.Comment: 22 page
Dynamics of the Born-Infeld dyons
The approach to the dynamics of a charged particle in the Born-Infeld
nonlinear electrodynamics developed in [Phys. Lett. A 240 (1998) 8] is
generalized to include a Born-Infeld dyon. Both Hamiltonian and Lagrangian
structures of many dyons interacting with nonlinear electromagnetism are
constructed. All results are manifestly duality invariant.Comment: 11 pages, LATE
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