Geometric Measure of Pairwise Quantum Discord for Superpositions of Multipartite Generalized Coherent States

TL;DR

This paper derives explicit formulas for pairwise quantum correlations, especially geometric quantum discord, in superpositions of multipartite coherent states and compares their robustness to entanglement under dephasing.

Contribution

It provides explicit expressions for quantum correlations in superpositions of multipartite coherent states and analyzes their dynamics under dephasing channels.

Findings

Quantum discord is more resilient to dissipation than entanglement.

Explicit formulas for quantum correlations in superpositions of coherent states.

Quantum correlations can interpolate between Werner and GHZ states.

Abstract

We give the explicit expressions of the pairwise quantum correlations present in superpositions of multipartite coherent states. A special attention is devoted to the evaluation of the geometric quantum discord. The dynamics of quantum correlations under a dephasing channel is analyzed. A comparison of geometric measure of quantum discord with that of concurrence shows that quantum discord in multipartite coherent states is more resilient to dissipative environments than is quantum entanglement. To illustrate our results, we consider some special superpositions of Weyl-Heisenberg, SU(2) and SU(1,1) coherent states which interpolate between Werner and Greenberger-Horne-Zeilinger states.