Electrically controllable surface magnetism on the surface of topological insulator

TL;DR

This paper theoretically investigates how the RKKY interaction mediated by Dirac electrons on topological insulator surfaces can be electrically controlled to manipulate surface magnetism, revealing complex spin interactions and potential for novel electronic effects.

Contribution

It provides an exact analytical expression for the RKKY interaction on topological insulator surfaces, including Heisenberg, Ising, and DM terms, enabling electrical control of surface magnetism.

Findings

RKKY interaction includes Heisenberg, Ising, and DM-like terms.

Electrical control can manipulate surface magnetic states.

Competition among interactions leads to diverse spin configurations.

Abstract

We study theoretically the RKKY interaction between magnetic impurities on the surface of three-dimensional topological insulators, mediated by the helical Dirac electrons. Exact analytical expression shows that the RKKY interaction consists of the Heisenberg-like, Ising-like and DM-like terms. It provides us a new way to control surface magnetism electrically. The gap opened by doped magnetic ions can lead to a short-range Bloembergen-Rowland interaction. The competition among the Heisenberg, Ising and DM terms leads to rich spin configurations and anomalous Hall effect on different lattices.