Current jetting distorted planar Hall effect in a Weyl semimetal with ultrahigh mobility

TL;DR

This study reports a giant planar Hall effect and anisotropic magnetoresistance in ultrahigh mobility Weyl semimetal TaP, highlighting the role of current jetting effects in deforming measurements and implications for spintronics applications.

Contribution

It reveals the origin of giant PHE/AMR in TaP as due to anisotropic orbital magnetoresistance and investigates the impact of mobility-enhanced current jetting effects.

Findings

Giant PHE and AMR observed in TaP.

Current jetting significantly deforms measurement curves.

Mobility influences the evolution of jetting effects with magnetic field and temperature.

Abstract

A giant planar Hall effect (PHE) and anisotropic magnetoresistance (AMR) is observed in TaP, a nonmagnetic Weyl semimetal with ultrahigh mobility. The perpendicular resistivity (i.e., the planar magnetic field applied normal to the current) far exceeds the zero-field resistivity, which thus rules out the possible origin of negative longitudinal magnetoresistance. The giant PHE/AMR is finally attributed to the large anisotropic orbital magnetoresistance that stems from the ultrahigh mobility. Furthermore, the mobility-enhanced current jetting effects are found to strongly deform the line shape of the curves, and their evolution with the changing magnetic field and temperature is also studied. Although the giant PHE/AMR suggests promising applications in spintronics, the enhanced current jetting shows the other side of the coin, which needs to be considered in the future device design.