Separable approximation for mixed states of composite quantum systems
量子物理
2009-11-07 v3
摘要
We describe a purely algebraic method for finding the best separable approximation to a mixed state of a composite 2x2 quantum system, consisting of a decomposition of the state into a linear combination of a mixed separable part and a pure entangled one. We prove that, in a generic case, the weight of the pure part in the decomposition equals the concurrence of the state.
引用
@article{arxiv.quant-ph/0104098,
title = {Separable approximation for mixed states of composite quantum systems},
author = {Thomas Wellens and Marek Kus},
journal= {arXiv preprint arXiv:quant-ph/0104098},
year = {2009}
}
备注
13 pages, no figures; minor changes; accepted for publication in PRA