Directional magnetoelectric effects in MnWO4: magnetic sources of the electric polarization

TL;DR

This paper provides a theoretical analysis of the magnetoelectric effects in MnWO4, highlighting the roles of both antisymmetric Dzyaloshinskii-Moriya interactions and symmetric interactions in generating electric polarization.

Contribution

It explicitly demonstrates the contributions of both antisymmetric and symmetric interactions to the magnetoelectric effects in MnWO4, expanding understanding of multiferroic mechanisms.

Findings

Dzyaloshinskii-Moriya interactions contribute to spin-electric dipole correlation.

Symmetric interactions also play a role in electric polarization.

Theoretical description of ferroelectric order in MnWO4's spiral phase.

Abstract

The ferroelectric order and magnetic field induced effects observed in the spiral phase of MnWO4 are described theoretically. It is demonstrated explicitly that the Dzyaloshinskii-Moriya antisymmetric interactions contribute to the correlation between spins and electric dipoles in the incommensurate and commensurate ferroelectric phases of magnetic multiferroics. However, other single-site symmetric interactions are shown to be involved in the magnetoelectric process, suggesting the possible existence of an electric polarization originating from purely symmetric effects.