Study on field-induced sign reversal of planar Hall effect in intrinsic ferromagnetic topological insulator MnBi8Te13

Abstract

The intrinsic ferromagnetic topological insulators MnBi₈Te₁₃ provide a promising material platform for the realization of diverse exotic topological quantum states, such as quantum anomalous Hall effect and axion-insulator state. The planar Hall effect (PHE) has significant advantages for the characterization of intrinsic magnetic properties in magnetic materials and applications to spintronic devices, due to its low thermal drift and high signal-to-noise ratio. In this work, the PHE of single crystal intrinsic ferromagnetic topological insulator MnBi₈Te₁₃ is studied in detail for the first time. Consistent with most PHE studies, the resulting PHE data demonstrate peaks and valleys near nπ/4 (n = 1, 2, 3, and 4) indicating a period of π. Interestingly, we observed a field-induced sign reversal of the PHE. Anisotropic magnetoresistance (AMR) measurements show that the sign reversal of resistivity can be attributed to the different dependence of resistivity on the magnetic field when the field is parallel and perpendicular to the current direction. Further analysis of the PHE and AMR data has demonstrated that the anisotropic magnetoresistance, rather than the chiral anomaly, plays a dominant role in the PHE of MnBi₈Te₁₃. These results advance the understanding of the planar Hall effect and provide a candidate material for field-controlled magnetic sensor devices.