Spin-1/2 anisotropic Heisenberg antiferromagnet with Dzyaloshinskii-Moriya interaction via mean-field approximation

TL;DR

This study uses mean-field approximation to analyze the phase transitions and magnetic properties of a spin-1/2 anisotropic Heisenberg antiferromagnet with Dzyaloshinskii-Moriya interaction, revealing only second-order transitions and no low-temperature anomalies.

Contribution

It provides a mean-field analysis of the model, showing the nature of phase transitions and correcting previous effective field theory results.

Findings

Only second-order phase transitions occur.

No anomalies at low temperatures.

Re-entrancy observed in some phase diagram regions.

Abstract

The spin-1/2 anisotropic Heisenberg model with antiferromagnetic exchange interactions in the presence of a external magnetic field and a Dzyaloshinskii-Moriya interaction is studied by employing the usual mean-field approximation. The magnetic properties are obtained and it is shown that only second-order phase transitions take place for any values of the theoretical Hamiltonian parameters. Contrary to previous results from effective field theory, no anomalies have been observed at low temperatures. However, some re-entrancies still persist in some region of the phase diagram.