35,763 research outputs found
Entanglement Entropy and Mutual Information in Bose-Einstein Condensates
In this paper we study the entanglement properties of free {\em
non-relativistic} Bose gases. At zero temperature, we calculate the bipartite
block entanglement entropy of the system, and find it diverges logarithmically
with the particle number in the subsystem. For finite temperatures, we study
the mutual information between the two blocks. We first analytically study an
infinite-range hopping model, then numerically study a set of long-range
hopping models in one-deimension that exhibit Bose-Einstein condensation. In
both cases we find that a Bose-Einstein condensate, if present, makes a
divergent contribution to the mutual information which is proportional to the
logarithm of the number of particles in the condensate in the subsystem. The
prefactor of the logarithmic divergent term is model dependent.Comment: 12 pages, 6 figure
Three realizations of quantum affine algebra
In this article we establish explicit isomorphisms between three realizations
of quantum twisted affine algebra : the Drinfeld ("current")
realization, the Chevalley realization and the so-called realization,
investigated by Faddeev, Reshetikhin and Takhtajan.Comment: 15 page
Features of pulsed synchronization of a systems with a tree-dimensional phase space
Features of synchronization picture in the system with the limit cycle
embedded in a three-dimensional phase space are considered. By the example of
Ressler system and Dmitriev - Kislov generator under the action of a periodic
sequence of delta - function it is shown, that synchronization picture
significantly depends on the direction of pulse action. Features of
synchronization tons appeared in these models are observed.Comment: 16 pages, 11 figure
Aberration corrections for free-space optical communications in atmosphere turbulence using orbital angular momentum states
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