Topological electric driving of magnetization dynamics in insulators

TL;DR

This paper introduces a topological mechanism for nondissipative electric control of magnetization dynamics in insulators, enabling sustained motion and energy transfer via nonconservative forces linked to electronic topology.

Contribution

It reveals a novel topological effect allowing electric driving of magnetization in insulators, supported by a hybrid system demonstrating quantized energy pumping despite damping.

Findings

Demonstration of sustained magnetization motion driven by electric fields.

Identification of a topology-based nonconservative electrical force.

Extension of the theory to magnetic textures and Dzyaloshinskii-Moriya interactions.

Abstract

Established forms of electromagnetic coupling are usually conservative (in insulators) or dissipative (in metals and semiconductors). Here we point out the possibility of nondissipative electric driving of magnetization dynamics, if the valence electronic states have nontrivial topology in the combined space of crystal momentum and magnetization configuration. We provide a hybrid insulator system to demonstrate that the topology-based nonconservative electrical generalized force is capable of supporting sustained magnetization motion in the presence of Gilbert damping, with quantized and steady energy pumping into magnetization motion from the electric field. We also generalize our results to magnetic textures, and discuss electric field induced Dzyaloshinskii-Moriya interaction which can be nonconservative.