Inverse Spin-Galvanic Effect in a Topological-Insulator/Ferromagnet Interface

TL;DR

This paper explores how a Hall current induced by an electric field in a topological insulator/ferromagnet interface can significantly influence magnetization dynamics, enabling dissipationless control of magnetic states with potential applications.

Contribution

It demonstrates the dissipationless Hall current effect on magnetization, revealing a novel mechanism for current-induced magnetic control in topological insulator/ferromagnet systems.

Findings

Hall current affects magnetization dynamics significantly

Dissipationless current-induced magnetization reversal is possible

Potential applications in low-power magnetic devices

Abstract

When a ferromagnet is deposited on the surface of a topological insulator the topologically protected surface state develops a gap and becomes a 2-dimensional quantum Hall liquid. We demonstrate that the Hall current in such a liquid, induced by an external electric field, can have a large effect on the magnetization dynamics of the ferromagnet by changing the effective anisotropy field. This change is dissipationless and may be substantial even in weakly spin-orbit coupled ferromagnets. We study the possibility of dissipationless current-induced magnetization reversal in monolayer-thin, insulating ferromagnets with a soft perpendicular anisotropy and discuss possible applications of this effect.