Magnetotransport signatures of chiral magnetic anomaly in the half-Heusler phase ScPtBi

TL;DR

This paper reports magnetotransport measurements on ScPtBi revealing signatures of chiral magnetic anomaly, confirms its semimetallic nature due to structural defects, and observes superconductivity below 0.7K.

Contribution

It provides experimental evidence of chiral magnetic anomaly signatures in ScPtBi and clarifies its electronic structure as a defect-induced semimetal.

Findings

Negative longitudinal magnetoresistance observed

Planar Hall effect detected

Superconductivity onset below 0.7K

Abstract

Study of magnetotransport properties of ScPtBi revealed simultaneously: a negative contribution to the longitudinal magnetoresistance, the planar Hall effect, and distinct angular narrowing of the longitudinal magnetoresistance { three hallmarks of chiral magnetic anomaly (pumping of axial charge between Weyl nodes), a distinct property of topological semimetals. Electronic structure calculations show that structural defects, such as antisites and vacancies, bring substantial density of states at the Fermi level of ScPtBi, indicating that it is a semimetal, not a zero-gap semiconductor, as predicted earlier. This is in accord with electrical resistivity in ScPtBi, showing no characteristics of semiconductor. Moreover, below 0.7K we observed an onset of a superconducting transition, with the resistivity disappearing completely below 0.23 K.