Robust linear magnetoresistance in WTe2

TL;DR

This study reports the discovery of robust linear magnetoresistance in WTe2, which persists under high magnetic fields and pressure, supported by experimental and theoretical analyses.

Contribution

It is the first to identify and analyze the persistent linear magnetoresistance in WTe2, revealing its robustness against high fields, pressure, and carrier imbalance.

Findings

Linear MR appears at low fields and dominates above 20 Tesla.

Linear MR remains unsaturated up to 60 Tesla and at 6.2 GPa pressure.

Unique quasilinear energy dispersion near the Fermi level observed.

Abstract

Unsaturated magnetoresistance (MR) has been reported in WTe2, and remains irrepressible up to very high field. Intense optimization of the crystalline quality causes a squarely-increasing MR, as interpreted by perfect compensation of opposite carriers. Herein we report our observation of linear MR (LMR) in WTe2 crystals, the onset of which is first identified by constructing the mobility spectra of the MR at low fields. The LMR further intensifies and predominates at fields higher than 20 Tesla while the parabolic MR gradually decays. The LMR remains unsaturated up to a high field of 60 Tesla and persists, even at a high pressure of 6.2 GPa. Assisted by density functional theory calculations and detailed mobility spectra, we find the LMR to be robust against the applications of high field, broken carrier balance, and mobility suppression. Angle-resolved photoemission spectroscopy reveals a unique quasilinear energy dispersion near the Fermi level. Our results suggest that the robust LMR is the low bound of the unsaturated MR in WTe2.