Topological Rare Earth Half-Heusler HoPtBi

Abstract

Magnetic HoPtBi is created and characterized as a new half-Heusler Weyl-candidate. By analogy with the well-studied GdPtBi system we undertake measurements intended to understand the normal state of this material, before extending our study to search for characteristics of Weyl behavior. We find a material with semiconducting properties as well as a low temperature antiferromagnetic transition below 1.25K and a Curie-Weiss paramagnetic system above. Analysis of the magnetoresistance in HoPtBi finds multiple Weyl-like characteristics, including potential chiral anomaly and anomalous Hall angle components. Finally we found significant anisotropic magnetoresistance in HoPtBi dependent on field alignment relative to the crystalline axes of the material, which is unexpected for a paramagnetic compound. We will show that these behaviors indicate a material with a Fermi surface readily tuned by application of magnetic field.