Helicity, anisotropies and their competition in a multiferroic magnet: insight from the phase diagram

TL;DR

This paper explores the complex magnetic phase diagram of MnWO4 by modeling the competition between anisotropy, magnetic field, and helicity using a mean-field approach, revealing various magnetic states.

Contribution

It provides a theoretical phase diagram for an anisotropic Heisenberg model that captures the competition of key magnetic interactions in MnWO4.

Findings

Identification of multiple incommensurate and commensurate magnetic states.

Comparison of theoretical phase diagram with experimental data.

Insights into the role of anisotropy and helicity in multiferroic magnets.

Abstract

Motivated by the complex phase diagram of MnWO4, we investigate competition between anisotropy, magnetic field, and helicity for the anisotropic next-nearest-neighbor Heisenberg model. Apart from two competing exchanges, which favor a spiral magnetic structure, the model features the bi-axial single-ion anisotropy. The model is treated in the real-space mean-field approximation and the phase diagram containing various incommensurate and commensurate states is obtained for different field orientations. We discuss similarities and differences of the theoretical phase diagram and the experimental diagram of MnWO4.