Tuning of anomalous magnetotransport properties in half-Heusler topological semimetal GdPtBi

TL;DR

This study investigates how shifting the Fermi level in GdPtBi affects its topological magnetotransport properties, revealing the persistent nature of Weyl node contributions despite energy level modifications.

Contribution

It demonstrates that the topological magnetotransport signatures in GdPtBi are robust against Fermi level shifts, highlighting the resilience of Weyl node effects in half-Heusler semimetals.

Findings

Negative longitudinal magnetoresistance persists despite Fermi level shifts.

Anomalous Hall effect varies with Fermi level due to Berry curvature.

Weyl node influence remains robust across energy modifications.

Abstract

Half-Heusler compounds from the $RE$PtBi family exemplify Weyl semimetals in which external magnetic field induce Weyl nodes. These materials exceptionally host topologically non-trivial states near the Fermi level and their manifestation can be clearly seen in the magnetotransport properties. In this study, we tune the Fermi level of the archetypal half-Heusler Weyl semimetal GdPtBi through high-energy electron irradiation, moving it away from the Weyl nodes to investigate the resilience of the contribution of topologically non-trivial states to magnetotransport properties. Remarkably, we observe that the negative longitudinal magnetoresistance, which is a definitive indicator of the chiral magnetic anomaly occurring in topological semimetals, persists even when the Fermi level is shifted by 100\,meV from its original position in the pristine sample. Additionally, the anomalous Hall effect shows complex variations as the Fermi level is altered, attributed to the energy-dependent nature of the Berry curvature, which arises from avoided band crossing. Our findings show the robust influence of Weyl nodes on the magneto-transport properties of GdPtBi, irrespective of the Fermi level position, a behaviour likely applicable to many half-Heusler Weyl semimetals.