Quantum discord of 2n-dimensional Bell-diagonal states

Abstract

In this study, using the concept of relative entropy as a distance measure of cor- relations we investigate the important issue of evaluating quantum correlations such as entanglement, dissonance and classical correlations for 2n-dimensional Bell-diagonal states. We provide an analytical technique, which describes how we find the closest classical states(CCS) and the closest separable states(CSS) for these states. Then analytical results are obtained for quantum discord of 2n-dimensional Bell-diagonal states. As illustration, some special cases are examined. Finally, we investigate the additivity relation between the different correlations for the separable generalized bloch sphere states.