Symmetric geometric measure and dynamics of quantum discord

TL;DR

This paper introduces a symmetric quantum correlation measure based on Hilbert-Schmidt distance, simplifies its calculation for two-qubit states, and explores its dynamic behavior under dissipative environments, revealing phenomena like correlation increase and sudden changes.

Contribution

It proposes a new symmetric quantum correlation measure, simplifies its computation, and analyzes its dynamics in open quantum systems, uncovering novel behaviors.

Findings

Quantum correlation can increase under dissipative noise

Sudden changes occur in the evolution of quantum correlation

Quantum correlation transfers from system to environment asymptotically

Abstract

A symmetric measure of quantum correlation based on the Hilbert-Schmidt distance is presented in this paper. For two-qubit states, we simplify considerably the optimization procedure so that numerical evaluation can be performed efficiently. Analytical expressions for the quantum correlation are attained for some special states. We further investigate the dynamics of quantum correlation of the system qubits in the presence of independent dissipative environments. Several nontrivial aspects are demonstrated. We find that the quantum correlation can increase even if the system state is suffering dissipative noise. Sudden changes occur, even twice, in the time evolution of quantum correlation. There is certain correspondence between the evolution of quantum correlation in the systems and that in the environments, and the quantum correlation in the systems will be transferred into the environments completely and asymptotically.