Temperature Dependent In-Plane Anisotropic Magnetoresistance in HfTe5 Thin LayersSupported by the National Key R&D Program (Grant Nos. 2017YFB0405703, 2017YFA0205004, and 2018YFA0306600), and the National Natural Science Foundation of China (Grant Nos. 11974327, 11474265, 11674295, 11674024, and 11874193), the Fundamental Research Funds for the Central Universities (Grant Nos. WK2030020032 and WK2340000082), Anhui Initiative in Quantum Information Technologies, and the Shenzhen Fundamental

Abstract

We report the observation of in-plane anisotropic magnetoresistance and planar Hall effect in non-magnetic HfTe5 thin layers. The observed anisotropic magnetoresistance as well as its sign is strongly dependent on the critical resistivity anomaly temperature T p. Below T p, the anisotropic magnetoresistance is negative with large negative magnetoresistance. When the in-plane magnetic field is perpendicular to the current, the negative longitudinal magnetoresistance reaches its maximum. The negative longitudinal magnetoresistance effect in HfTe5 thin layers is dramatically different from that induced by the chiral anomaly as observed in Weyl and Dirac semimetals. One potential underlying origin may be attributed to the reduced spin scattering, which arises from the in-plane magnetic field driven coupling between the top and bottom surface states. Our findings provide valuable insights for the anisotropic magnetoresistance effect in topological electronic systems and the device potential of HfTe5 in spintronics and quantum sensing.