Properties of a geometric measure for quantum discord

TL;DR

This paper examines the properties of a geometric quantum discord measure, analyzing its effectiveness, dependence on state mixedness, and relation to non-locality in Werner and MEM states.

Contribution

It provides a detailed analysis of the geometric quantum discord measure's properties and its relation to non-locality and mixedness in specific quantum states.

Findings

The geometric measure effectively captures quantum discord in Werner and MEM states.

Quantum discord varies with the degree of mixedness of bipartite states.

There is a connection between quantum discord and Bell inequality violations.

Abstract

We discuss some properties of the quantum discord based on the geometric distance advanced by Dakic, Vedral, and Brukner [Phys. Rev. Lett. {\bf 105}, 190502 (2010)], with emphasis on Werner- and MEM-states. We ascertain just how good the measure is in representing quantum discord. We explore the dependence of quantum discord on the degree of mixedness of the bipartite states, and also its connection with non-locality as measured by the maximum violation of a Bell inequality within the CHSH scenario.