Quantum correlation in three-qubit Heisenberg model with Dzyaloshinskii-Moriya interaction

TL;DR

This paper studies how Dzyaloshinskii-Moriya interaction affects quantum discord in a three-qubit Heisenberg model, revealing its impact on quantum correlations and their dynamics at finite temperatures.

Contribution

It provides new insights into the influence of Dzyaloshinskii-Moriya interaction on quantum discord and its abrupt changes in a three-qubit Heisenberg system.

Findings

Dzyaloshinskii-Moriya interaction can increase quantum discord in antiferromagnetic systems.

Quantum discord exhibits abrupt changes indicating ground state transitions.

Thermal discord vanishes asymptotically, while entanglement disappears suddenly at finite time.

Abstract

We investigate the pairwise thermal quantum discord in a three-qubit XXZ model with Dzyaloshinskii-Moriya (DM) interaction. We find that the DM interaction can increase quantum discord to a fixed value in the anti- ferromagnetic system, but decreases quantum discord to a minimum first, then increases it to a fixed value in the ferromagnetic system. Abrupt change of quantum discord is observed, which indicates the abrupt change of groundstate. Dynamics of pairwise thermal quantum discord is also considered. We show that thermal discord vanishes in asymptotic limit regardless of its initial values, while thermal entanglement suddenly disappears at finite time.