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

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 10 K 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.

Anomalous Hall effect and negative longitudinal magnetoresistance in half-Heusler topological semimetal candidates TbPtBi and HoPtBi

“…The latter features entirely disappear at T = 100 K. A similar behavior of AMR was reported before for GdPtBi 59 and DyPdBi. 51 In our recent work, 51 we attributed this effect to the crystalline anisotropy of the single crystals examined, and we suppose that such an explanation is suitable also for HoPtBi. However, it should be recalled that a similar angle-dependent magnetoresistance was reported also for the archetypal nodal-line Dirac semimetal ZrSiS, and the authors called such an unusual phenomenon butterfly magnetoresistance.…”

“…The isotherms ρ xy (B) are curvilinear, which may arise from the strong dependence of the electronic structure on the magnetic field or point to the multi-band type of conductivity, typical for half-Heusler compounds. 10,51 Remarkably, non-linear ρ xy (B) is also a strong indication of AHE. 28,33,49 In an attempt to determine the origin of the Hall effect in the studied compounds, we used the multi-band Drude model:…”

The sign of longitudinal magnetoconductivity and the planar Hall effect in Weyl semimetals

“…Secondly, the consequence of intervalley scattering in the presence of OMM on the planar Hall effect has not yet been explored. This is another equally important problem, given the fact that several works have reported the measurement of planar Hall effect on Weyl systems [34][35][36][37][38][39][40][41]. The current manuscript addresses these two questions, and solves the Boltzmann equation for a prototype of a Weyl semimetal in setup where the E and B fields are non-collinear.…”

“…The current conservation law dictates ∂ µ j χ µ = e 2 h 2 E • B, indicating charge pumping from one Weyl node to the other as long as E • B = 0. Chiral anomaly has become one of the most prominent effects with origin in high energy physics that has been verified in condensed matter physics experiments, with possible experimental signatures expected to arise from positive longitudinal magnetoconductance (LMC) [24][25][26][27][28][29][30][31][32], planar Hall effect [33][34][35][36][37][38][39][40][41], optical gyrotropy [22], and thermopower [42][43][44].…”

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

“…All three have never been observed simultaneously in the same material. Negative LMR has been found in many topological semimetals, for example: TaAs, TaP, ZrTe 5 , Na 3 Bi, GdPtBi, and YbPtBi 3,[5][6][7][8][9][10] PHE was observed less often, in Cd 3 As 2 , VAl 3 , Na 3 Bi, as well as half-Heusler phases GdPtBi, YbPtBi, and DyPdBi [10][11][12][13][14][15] . To date, angular narrowing of negative LMR has been found only in Na 3 Bi 3 .…”