MIXED STATE ENTANGLEMENT MEASURES FOR INTERMEDIATE SEPARABILITY
TSUBASA ICHIKAWA, Marcus Huber, PHILIPP KRAMMER +1 more
To determine whether a given multipartite quantum state is separable with respect to some partition, we construct a family of entanglement measures {Rm(ρ)}. This is done utilizing generalized concurrences as building blocks which are defined by flipping of M constituents and indicate states that are separable with regard to bipartitions when vanishing. Furthermore, we provide an analytically computable lower bound for {Rm(ρ)} via a simple ordering relation of the convex roof extension. Using the derived lower bound, we illustrate the effect of the isotropic noise on a family of four-qubit mixed states for each intermediate separability.
arXiv:0911.4245•International Journal of Quantum Information•Jun 1, 2010•1 citation