Electric charging of magnetic textures on the surface of a topological insulator

TL;DR

This paper explores how magnetic textures on a topological insulator's surface can acquire electric charge due to the Dirac surface states, enabling electric control of magnetic domain walls for efficient devices.

Contribution

It introduces a theoretical framework linking magnetic textures to electric charges on topological insulator surfaces, proposing electric field-driven domain wall motion.

Findings

Magnetic textures can be electrically charged via proximity to Dirac surface states.

A general relation between electric and magnetic charges is derived.

Electric fields can drive domain wall motion, promising efficient magnetic devices.

Abstract

A three-dimensional topological insulator manifests gapless surface modes, described by two-dimensional Dirac equation. We study magnetic textures, such as domain walls and vortices, in a ferromagnetic thin film deposited on a three-dimensional topological insulator. It is shown that these textures can be electrically charged, ascribed to the proximity effect with the Dirac surface states. We derive a general relation between the electric and the magnetic charges. As a physical consequence, we discuss domain wall motion driven by an applied electric field, which promises magnetic devices with high thermal efficiency.