Characterization of separable states and entanglement witnesses
Quantum Physics
2009-11-06 v1
Abstract
We provide a canonical form of mixed states in bipartite quantum systems in terms of a convex combination of a separable state and a, so-called, edge state. We construct entanglement witnesses for all edge states. We present a canonical form of nondecomposable entanglement witnesses and the corresponding positive maps. We provide constructive methods for their optimization in a finite number of steps. We present a characterization of separable states using a special class of entanglement witnesses. Finally, we present a nontrivial necessary condition for entanglement witnesses and positive maps to be extremal.
Keywords
Cite
@article{arxiv.quant-ph/0005112,
title = {Characterization of separable states and entanglement witnesses},
author = {M. Lewenstein and B. Kraus and P. Horodecki and J. I. Cirac},
journal= {arXiv preprint arXiv:quant-ph/0005112},
year = {2009}
}
Comments
4 pages, 1 figure