Perspective–The Elusive Quantum Anomalous Hall Effect in MnBi2Te4: Materials

Observation of the quantum anomalous Hall effect (QAHE) in MnBi2Te4 flakes is one of the most exciting results in the study of the intrinsic magnetic topological insulator MnBi2Te4 and related compounds. However, reproducing this fascinating result has been found to be challenging. The quality of starting MnBi2Te4 single crystals is believed to be the key factor. An interesting and important question to address is what is the right quality to enable the QAHE. In this perspective, we present possible approaches to tuning the magnetic and topological properties of MnBi2Te4 by using lattice imperfections, strain, stacking sequence, and interactions between the substrate and flakes/films. It is of critical importance to eventually identify the factor(s) responsible for the realization of QAHE. This paper is part of the JES/JSS Joint Focus Issue In Honor of John Goodenough: A Centenarian Milestone.