Angular dependence of large negative magnetoresistance in a field-induced Weyl semimetal candidate HoAuSn

TL;DR

This study investigates the angular dependence of large negative magnetoresistance in HoAuSn, revealing that magnetic field-induced Weyl points significantly influence electronic properties, with potential implications for topological materials.

Contribution

It demonstrates that magnetic field-induced Weyl points cause large negative MR in HoAuSn, providing new insights into topological states in antiferromagnetic half-Heusler compounds.

Findings

Negative MR up to 99% at 9 T

MR persists up to 20 K, above Neel temperature

Magnetic field reconstructs band structure inducing Weyl points

Abstract

The angular dependence of magnetoresistance (MR) in antiferromagnetic half-Heusler HoAuSn single crystals have been systematically studied. Negative MR, as large as 99%, is observed at 9 T, is not restricted to the specific configuration of applied magnetics fields and current, and can persist up to 20 K, much higher than the Neel temperature (TN 1.9 K). Experiments and first-principles calculations suggest that the observed large negative MR is derived from a magnetic field that reconstructs the band structure and induces a Weyl point, which changes the carrier concentration. Taking into consideration that large negative MR has so far been rarely reported, especially in antiferromagnetic materials, it is anticipated that the present work not only offers a guideline for searching materials with large negative MR but also helps to further realize other exotic topological electronic states in a large class of antiferromagnetic half-Heusler compounds.