Separability and Entanglement of Quantum States Based on Covariance Matrices

TL;DR

This paper explores criteria for determining quantum state separability using covariance matrices, offering improved bounds on concurrence through optimized local observables, with implications for multipartite quantum systems.

Contribution

It introduces new separability criteria based on covariance matrices and enhances the lower bounds of concurrence by optimizing local observables.

Findings

New criteria for quantum state separability based on covariance matrices

Improved lower bounds of concurrence through optimization

Applicability to multipartite quantum states

Abstract

We investigate the separability of quantum states based on covariance matrices. Separability criteria are presented for multipartite states. The lower bound of concurrence proposed in Phys. Rev. A. 75, 052320 (2007) is improved by optimizing the local orthonormal observables.