Intrinsic magnetic topological insulator phases in the Sb doped MnBi2Te4 bulks and thin flakes

TL;DR

This paper reports the discovery of intrinsic magnetic topological insulator phases in Sb-doped MnBi2Te4, demonstrating potential for high-temperature quantum anomalous Hall effects and advancing the understanding of topological magnetic materials.

Contribution

It introduces a new family of Mn(SbxBi(1-x))2Te4 materials with intrinsic MTI phases, combining experimental growth, spectroscopy, transport measurements, and first-principles calculations.

Findings

Existence of an optimized MTI zone in the phase diagram.

Potential for high-temperature quantum anomalous Hall phase.

Identification of promising materials for device applications.

Abstract

Magnetic topological insulators (MTIs) offer a combination of topologically nontrivial characteristics and magnetic order and show promise in terms of potentially interesting physical phenomena such as the quantum anomalous Hall (QAH) effect and topological axion insulating states. However, the understanding of their properties and potential applications have been limited due to a lack of suitable candidates for MTIs. Here, we grow two-dimensional single crystals of Mn(SbxBi(1-x))2Te4 bulk and exfoliate them into thin flakes in order to search for intrinsic MTIs. We perform angle-resolved photoemission spectroscopy, low-temperature transport measurements, and first-principles calculations to investigate the band structure, transport properties, and magnetism of this family of materials, as well as the evolution of their topological properties. We find that there exists an optimized MTI zone in the Mn(SbxBi(1-x))2Te4 phase diagram, which could possibly host a high-temperature QAH phase, offering a promising avenue for new device applications.