Angle dependent field-driven reorientation transitions in uniaxial antiferromagnet MnBi$_2$Te$_4$ single crystal

TL;DR

This study investigates how magnetic field orientation affects magnetic reorientation transitions in MnBi$_2$Te$_4$, revealing insights into magnetic interactions and anisotropy relevant for topological quantum phenomena.

Contribution

It provides a systematic analysis of angle-dependent magnetotransport and magnetization, estimating magnetic interaction parameters and explaining data with Monte Carlo simulations.

Findings

Magnetic field direction significantly influences critical fields and magnetic structure.

Field-driven reorientation transitions enable estimation of exchange interactions and anisotropy.

Monte Carlo simulations successfully reproduce experimental results.

Abstract

MnBi$_2$Te$_4$, a two-dimensional magnetic topological insulator with a uniaxial antiferromagnetic structure, is an ideal platform to realize quantum anomalous Hall effect. However, the strength of magnetic interactions is not clear yet. We performed systematic studies on the magnetization and angle dependent magnetotransport of MnBi$_2$Te$_4$ single crystal. The results show that the direction of the magnetic field has significant effects on the critical field values and magnetic structure of this compound, which leads to different magnetotransport behaviors. The field-driven reorientation transitions can be utilized to estimate the AFM interlayer exchange interaction coupling and uniaxial magnetic anisotropy D. The obtained Hamiltonian can well explain the experimental data by Monte Carlo simulations. Our comprehensive studies on the field-driven magnetic transitions phenomenon in MnBi$_2$Te$_4$ provide a general approach for other topological systems with antiferromagnetism.