Tunable intrinsic ferromagnetic topological phases in bulk van der Waals crystal MnSb6Te10

TL;DR

This study identifies MnSb6Te10 as a tunable intrinsic magnetic topological material that exhibits various phases such as ferromagnetic, antiferromagnetic, axion insulator, and Weyl semimetal, controlled by temperature, magnetic field, and doping.

Contribution

It demonstrates the realization and tunability of multiple topological phases in MnSb6Te10 through combined experimental and theoretical approaches.

Findings

MnSb6Te10 exhibits a fragile ferromagnetic ground state.

The material can transition into ferrimagnetic and antiferromagnetic topological insulator phases with temperature.

It can be converted into a Weyl semimetal with hole doping, showing a notable anomalous Hall effect.

Abstract

Intrinsic ferromagnetism is a crucial ingredient to realize quantum anomalous Hall effect in quasi two dimensional materials, thus the search of intrinsic ferromagnetic topological materials is one of the most concerned issues in the field of topological phases of matter. In this work, combining magnetotransport measurements, first principles calculations, and angle-resolved photoemission spectroscopy studies, we find that in MnSb6Te10, the n = 2 member of the MnSb2Te4/(Sb2Te3)n family, the strong magnetic competition realizes a fragile ferromagnetic ground state, which whereas easily enters into ferrimagnetic and the Z_2 antiferromagnetic topological insulator phase with warming to higher temperature. Interestingly, the system stays in an inversion-symmetry-protected axion insulator phase in the ferromagnetic ground state as well as in the external magnetic field driven spin-polarized FM phase and can be converted into a Weyl semimetal with multiple Weyl nodes in the valence bands with hole doping, which are manifested by the measured notable intrinsic anomalous Hall effect. Our work thus provides an intrinsic magnetic topological material which is highly tunable into versatile topological phases by temperature, magnetic field, as well as carrier doping.