Large anomalous Hall angle accompanying the sign change of anomalous Hall conductance in the topological half-Heusler compound HoPtBi

Abstract

Controlling the anomalous Hall effect (AHE) in magnetic topological materials is an important property. Because of the close relationship between anomalous Hall conductance (AHC) and topological band (strong Berry curvature), AHC can be effectively tuned by magnetic field combined with strong spin-orbit interaction and special band structure. In this work, we observed a magnetic field driving the nonmonotonic magnetic field dependence of anomalous Hall resistivity and the sign change in magnetic-field-induced Weyl semimetal HoPtBi. The tunable ranges of the AHC and the anomalous Hall angle are $\ensuremath{-}75\ensuremath{\sim}73\phantom{\rule{0.16em}{0ex}}{\mathrm{\ensuremath{\Omega}}}^{--1}\phantom{\rule{0.16em}{0ex}}\mathrm{c}{\mathrm{m}}^{--1}$ and $\ensuremath{-}12.3\ensuremath{\sim}9.1%$, respectively. Anisotropic measurements identified the magnetic field is the key factor in controlling the additional Hall term sign. Further analysis indicated that it originated from the field-induced shift of the Weyl points via exchange splitting of bands near the Fermi level. The large tunable effect of the magnetic field on the electronic band structure provides a path to tune the topological properties in this system. These findings suggest that HoPtBi is a good platform for tuning the Berry phase and AHC with the magnetic field.