Negative longitudinal magnetoresistance as a sign of a possible chiral magnetic anomaly in the half-Heusler antiferromagnet DyPdBi

TL;DR

This study reports large negative longitudinal magnetoresistance and planar Hall effect in DyPdBi, suggesting the presence of a chiral magnetic anomaly linked to Weyl semimetal behavior, with findings supported by detailed magnetotransport measurements.

Contribution

It provides experimental evidence of chiral magnetic anomaly in DyPdBi, a half-Heusler antiferromagnet, through comprehensive magnetotransport analysis and ruling out extrinsic effects like current-jetting.

Findings

Negative magnetoresistance up to -80% at 14 T and 10K.

Non-monotonous temperature and field dependence of planar Hall effect.

Minimal influence of current-jetting on observed effects.

Abstract

Magnetotransport investigation of a half-Heusler antiferromagnet DyPdBi revealed hallmark features of Weyl semimetal: huge negative longitudinal magnetoresistance and planar Hall effect. Both effects have recently been linked to chiral magnetic anomaly - axial charge pumping between Weyl nodes. Magnetoresistance (MR) of single crystals of DyPdBi is very pronounced. In magnetic field longitudinal to electrical current direction it reaches -80% and its relative difference with respect to that measured in transverse field (expressed as anisotropic magnetoresistance) is extremely strong: -60% at 10K and 14 T. The planar Hall effect in DyPdBi depends on temperature and magnetic field in non-monotonous way, which has not been previously reported. We compare magnetoresistance measured with voltage contacts on mid-line of the sample with that measured with contacts on its edge, and show that the role of current-jetting, an extrinsic source of anisotropic negative magnetoresistance, is marginal. We discuss that nature of the compound and sample quality exclude intrinsic sources of negative and anisotropic magnetoresistance other than weak localization and the chiral magnetic anomaly.