Revealing Tripartite Quantum Discord with Tripartite Information Diagram

TL;DR

This paper introduces a new measure based on tripartite information diagrams to identify quantum discord in tripartite systems, extending bipartite concepts and demonstrating its effectiveness on well-known quantum states.

Contribution

It proposes a novel tripartite quantum discord measure using information diagrams and measurement strategies, applicable to general N-partite systems.

Findings

Successfully evaluated tripartite quantum discord for GHZ, W, and biseparable states.

Connected tripartite discord with genuine tripartite entanglement and EPR steering.

Framework can be extended to N-partite quantum systems.

Abstract

A new measure based on the tripartite information diagram is proposed for identifying quantum discord in tripartite systems. The proposed measure generalizes the mutual information underlying discord from bipartite to tripartite systems, and utilizes both one-particle and two-particle projective measurements to reveal the characteristics of the tripartite quantum discord. The feasibility of the proposed measure is demonstrated by evaluating the tripartite quantum discord for systems with states close to Greenberger-Horne-Zeilinger, W, and biseparable states. In addition, the connections between tripartite quantum discord and two other quantum correlations---namely genuine tripartite entanglement and genuine tripartite Einstein-Podolsky-Rosen steering---are briefly discussed. The present study considers the case of quantum discord in tripartite systems. However, the proposed framework can be readily extended to general N-partite systems.