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, which allows us to introduce a canonical form of nondecomposable entanglement witnesses and the corresponding positive maps. We also present a nontrivial necessary condition for entanglement witnesses and positive maps to be extremal.
No takes yet. Share an insight, caveat, or question.
Lewenstein et al. (2001) studied this question.
Synapse has enriched 4 closely related papers on similar clinical questions. Consider them for comparative context: