Quantum discord under system-environment coupling: the two-qubit case

TL;DR

This paper reviews how system-environment interactions influence quantum discord in two-qubit systems, emphasizing the role of initial correlations and external controls in open quantum system dynamics.

Contribution

It provides a comprehensive overview of the dynamics of two-qubit quantum discord under system-environment coupling, including experimental insights and the effects of initial correlations.

Findings

Initial system-environment correlations significantly affect quantum discord dynamics.

External control can modulate quantum discord in open quantum systems.

Experimental studies support theoretical models of discord evolution.

Abstract

Open quantum systems have attracted great attention, since inevitable coupling between quantum systems and their environment greatly affects the features of interest of these systems. Quantum discord, is a measure of the total nonclassical correlation in a quantum system that includes, but is not exclusive to, the distinct property of quantum entanglement. Quantum discord can exist in separated quantum states and plays an important role in many fundamental physics problems and practical quantum information tasks. There have been numerous investigations on quantum discord and its counterpart classical correlation. This short review focuses on highlighting the system-environment dynamics of two-qubit quantum discord and the influence of initial system-environment correlations on the dynamics of open quantum systems. The external control effect on the dynamics of open quantum systems are involved. Several related experimental works are discussed.