Angle dependent field-driven reorientation transitions in uniaxial antiferromagnet MnBi2Te4 single crystal

Abstract

MnBi2Te4, a two-dimensional magnetic topological insulator with a uniaxial antiferromagnetic structure, is an ideal platform to realize quantum anomalous Hall effects. However, the strength of magnetic interactions is not clear yet. We performed systematic studies on the magnetization and angle dependent magnetotransport on MnBi2Te4 single crystals. The results show that the direction of the magnetic field has significant effects on the critical field values and the magnetic structure of this compound, which lead to different magnetotransport behaviors. The field-driven reorientation transitions can be utilized to estimate the antiferromagnetic interlayer exchange interaction coupling Jc 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 transition phenomenon in MnBi2Te4 provide a general approach for other topological systems with antiferromagnetism.