Thermal quantum discord in the anisotropic Heisenberg XXZ model with the Dzyaloshinskii-Moriya interaction

TL;DR

This paper investigates the behavior of thermal quantum discord in a two-qubit Heisenberg XXZ model with Dzyaloshinskii-Moriya interaction, revealing unique properties and control mechanisms distinct from entanglement.

Contribution

It provides a comparative analysis of quantum discord and entanglement, highlighting the exotic characteristics of QD and the effectiveness of tunable parameters D_x and D_z in controlling quantum correlations.

Findings

Quantum discord can asymptotically approach zero with temperature while entanglement vanishes at a critical point.

Tunable parameters D_x and D_z influence QD differently, with D_x generally being more effective.

Qd exhibits exotic behavior, offering potential for enhancing quantum correlations in the system.

Abstract

The thermal quantum discord (QD) is studied in a two-qubit Heisenberg XXZ system with Dzyaloshinskii-Moriya (DM) interaction. We compare the thermal QD with thermal entanglement in this system and find remarkable differences between them. For instance, we show situations where QD decreases asymptotically to zero with temperature $T$ while entanglement decreases to zero at the point of critical temperature, situations where QD decreases with certain tunable parameters such as $D_z$ and $D_x$ when entanglement increases. We find that the characteristic of QD is exotic in this system and this possibly offers a potential solution to enhance entanglement of a system. We also show that tunable parameter $D_x$ is more efficient than parameter $D_z$ in most regions for controlling the QD.