Thermal and thermoelectric properties of an antiferromagnetic topological insulator MnBi${}_2$Te${}_4$

Abstract

The discovery of an intrinsic antiferromagnetic topological insulator (AFM-TI) in MnBi${}_2$Te${}_4$ has attracted intense attention, most of which lies on its electrical properties. In this paper, we report electronic, thermal, and thermoelectric transport studies of this newly found AFM-TI. The temperature and magnetic field dependence of its resistivity, thermal conductivity, and Seebeck coefficient indicate strong coupling between charge, lattice, and spin degrees of freedom in this system. Furthermore, MnBi${}_2$Te${}_4$ exhibits a large anomalous Nernst signal, which is associated with non-zero Berry curvature of the field-induced canted antiferromagnetic state.

submitted in Oct. 2021, accepted for publication in Phys. Rev. B