The importance of the electronic contribution to linear magnetoelectricity

TL;DR

This paper reveals that the electronic contribution to linear magnetoelectricity is significant and often overlooked, comparable to lattice effects, and introduces a simple computational approach to study these responses.

Contribution

It demonstrates the importance of electronic contributions in magnetoelectric response and presents a straightforward method to analyze both electronic and lattice-mediated effects.

Findings

Electronic contribution can be as large as lattice-mediated response.

The proposed method applies to both linear and non-linear magnetic responses.

Electronic and lattice effects together explain the magnetoelectric behavior.

Abstract

We demonstrate that the electronic contribution to the linear magnetoelectric response, usually omitted in first-principles studies, can be comparable in magnitude to that mediated by lattice distortions, even for materials in which responses are strong. Using a self-consistent Zeeman response to an applied magnetic field for noncollinear electron spins, we show how electric polarization emerges in linear magnetoelectrics through both electronic- and lattice-mediated components -- in analogy with the high- and low-frequency dielectric response to an electric field. The approach we use is conceptually and computationally simple, and can be applied to study both linear and non-linear responses to magnetic fields.