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On the P-representable subset of all bipartite Gaussian separable states

M. C. de Oliveira
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Abstract

P-representability is a necessary and sufficient condition for separability of bipartite Gaussian states only for the special subset of states whose covariance matrix are $Sp(2,R)\otimes Sp(2,R)$ locally invariant. Although this special class of states can be reached by a convenient $Sp(2,R)\otimes Sp(2,R)$ transformation over an arbitrary covariance matrix, it represents a loss of generality, avoiding inference of many general aspects of separability of bipartite Gaussian states.

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M. C. de Oliveira. 2004-07-20. On the P-representable subset of all bipartite Gaussian separable states. https://doi.org/10.1103/physreva.70.034303

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