Anomalous Hall effect and negative longitudinal magnetoresistance in half-Heusler topological semimetal candidates TbPtBi and HoPtBi

TL;DR

This study investigates the topologically non-trivial electronic properties of TbPtBi and HoPtBi, revealing giant magnetoresistance, anomalous Hall effect, and complex Fermi surface features indicative of their potential as topological semimetals.

Contribution

It provides a detailed experimental analysis of magnetotransport in TbPtBi and HoPtBi, highlighting their anomalous Hall effect and negative longitudinal magnetoresistance as signatures of topological electronic states.

Findings

Giant transverse magnetoresistance without saturation up to 14 T

Observation of negative longitudinal magnetoresistance

Detection of anomalous Hall effect likely due to Berry curvature

Abstract

Half-Heusler compounds have attracted significant attention because of their topologically non-trivial electronic structure, which leads to unusual electron transport properties. We thoroughly investigated the magnetotransport properties of high-quality single crystals of two half-Heusler phases, TbPtBi and HoPtBi, in pursuit of the characteristic features of topologically non-trivial electronic states. Both studied compounds are characterized by the giant values of transverse magnetoresistance with no sign of saturation in magnetic field up to 14 T. HoPtBi demonstrates the Shubnikov-de Haas effect with two principal frequencies, indicating a complex Fermi surface; the extracted values of carrier effective masses are rather small, $0.18\,m_e$ and $0.27\,m_e$. The investigated compounds exhibit negative longitudinal magnetoresistance and anomalous Hall effect, which likely arise from a nonzero Berry curvature. Both compounds show strongly anisotropic magnetoresistance, that in HoPtBi exhibits a butterfly-like behavior.