Intrinsic magnetic topological insulators

TL;DR

This paper reviews recent progress in intrinsic magnetic topological insulators, especially MnBi2Te4, highlighting their potential to enable higher-temperature quantum anomalous Hall effects and novel topological states.

Contribution

It provides a comprehensive overview of intrinsic magnetic topological insulators, focusing on their properties, synthesis, and potential for advancing topological quantum phenomena.

Findings

Intrinsic magnetic topological insulators can host quantum anomalous Hall effect at higher temperatures.

MnBi2Te4 and related materials are promising candidates for intrinsic magnetic topological insulators.

Research progress includes synthesis, characterization, and understanding of magnetic and topological properties.

Abstract

Introducing magnetism into topological insulators breaks time-reversal symmetry, and the magnetic exchange interaction can open a gap in the otherwise gapless topological surface states. This allows various novel topological quantum states to be generated, including the quantum anomalous Hall effect (QAHE) and axion insulator states. Magnetic doping and magnetic proximity are viewed as being useful means of exploring the interaction between topology and magnetism. However, the inhomogeneity of magnetic doping leads to complicated magnetic ordering and small exchange gaps, and consequently the observed QAHE appears only at ultralow temperatures. Therefore, intrinsic magnetic topological insulators are highly desired for increasing the QAHE working temperature and for investigating topological quantum phenomena further. The realization and characterization of such systems are essential for both fundamental physics and potential technical revolutions. This review summarizes recent research progress in intrinsic magnetic topological insulators, focusing mainly on the antiferromagnetic topological insulator MnBi2Te4 and its family of materials.