Direct scheme for measuring the geometric quantum discord

TL;DR

This paper introduces a direct, efficient, and experimentally feasible scheme for measuring the geometric quantum discord of any two-qubit state, reducing complexity compared to traditional quantum state tomography.

Contribution

The paper presents a novel method for directly measuring geometric quantum discord using projective measurements in the anti-symmetric subspace, improving efficiency and practicality.

Findings

Scheme requires fewer parameter estimations than tomography

Can be implemented with current experimental techniques

Provides exact geometric quantum discord measurement

Abstract

We propose a scheme to directly measure the exact value of geometric quantum discord of an arbitrary two-qubit state. We only need to perform the projective measurement in the all anti-symmetric subspace and our scheme is parametrically efficient in contrast to the widely adopted quantum state tomography scheme in the sense of less parameter estimations and projectors. Moreover, the present scheme can be easily realized with the current experimental techniques.