Linear Magnetoelectric Electro-Optic Effect

TL;DR

This paper derives a generalized constitutive relation for electromagnetic responses in quantum materials, revealing novel electro-optic effects driven by Berry curvature and magnetic moments, including a magnetoelectric effect requiring symmetry breaking.

Contribution

It introduces a new theoretical framework linking Berry curvature, magnetic moments, and electro-optic effects, including the magnetoelectric effect in chiral materials.

Findings

Electro-optic effects induced by Berry curvature dipole.

Existence of a magnetoelectric electro-optic effect requiring symmetry breaking.

Explicit tensor forms for chiral space groups 152 and 198.

Abstract

In this work, we derive a generalized constitutive relation describing the current response to external electromagnetic fields in electrically biased quantum materials. While our semiclassical Boltzmann approach reveals the existence of electro-optic effects induced by the Berry curvature dipole of Bloch electrons, we also find a wealth of alternative electro-optic effects originating from the interplay between Berry curvature and magnetic moment. In particular, our symmetry analysis indicates the existence of a magnetoelectric electro-optic effect, derived from the simultaneous presence of Berry curvature and magnetic moment, that requires either time-reversal or inversion symmetry breaking. The revealed conductivity coefficients are explicitly written and we derive the tensor shape describing such alternative electromagnetic responses for chiral materials pertaining to space groups 152 and 198.