Lewenstein-Sanpera Decomposition for Iso-concurrence Decomposable States

S. J. Akhtarshenas, M. A. Jafarizadeh

备注：: 16 pages, Latex

英文摘要：

We obtain Lewenstein-Sanpera decomposition of iso-concurrence decomposable states of $2\otimes 2$ quantum systems. It is shown that in these systems average concurrence of the decomposition is equal to the concurrence of the state and also it is equal to the amount of violation of positive partial transpose criterion. It is also shown that the product states introduced by Wootters in [W. K. Wootters, Phys. Rev. Lett. {\bf 80} 2245 (1998)] form the best separable approximation ensemble for these states.

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