Gap Generation in Topological Insulator Surface States by non-Ferromagnetic Magnets

TL;DR

This paper demonstrates that surface states of 3D topological insulators can develop spectral gaps when coupled with certain antiferromagnetic or ferrimagnetic thin films, challenging previous assumptions.

Contribution

It introduces a novel mechanism for gap generation in topological insulator surface states using non-ferromagnetic magnetic films.

Findings

Spectral gaps can be induced by antiferromagnetic or ferrimagnetic insulators.

The mechanism works contrary to naive expectations.

Potential applications in topological electronics.

Abstract

It is shown that, contrary to the naive expectation, single particle spectral gaps can be opened on the surface states of three dimensional topological insulators by using commensurate out- and in-plane antiferromagnetic or ferrimagnetic insulating thin films.