Effect of Dzyaloshinskii-Moriya Interaction on Thermal Quantum Correlation in a Two-Qubit Heisenberg XXZ Model with an Inhomogeneous External Magnetic Field

Abstract

By using the two-qubit Heisenberg XXZ model with Dzyaloshinskii-Moriya (DM) interaction and an inhomogeneous external magnetic field, we investigate the similarities and differences of negativity (N), quantum discord (QD), and measurement-induced disturbance (MID) and the behaviors of quantum phase transition (QPT) at finite temperature. The results indicate that DM interaction D can enhance the N, QD, and MID, while the uniform magnetic field B suppresses them, and the role played by the inhomogeneity b of magnetic field in N is obviously different from those in QD and MID for the smaller D region. Moreover, compared with N, we notice the QD and MID are more general measures of the thermal quantum correlation (TQC). And that the MID cannot completely replace the QD has been discovered. It is also observed that the DM interaction is a more optimal parameter than the inhomogeneous external magnetic field in the process of improving the TQC measured by QD and MID at the higher temperature. In addition, we note that the DM interaction and an inhomogeneous external magnetic field present remarkable different effects on the behavior of the QPT point at finite temperature.