Electronic structure basis for the titanic magnetoresistance in WTe$_2$

TL;DR

This study reveals that the large magnetoresistance in WTe₂ is due to its balanced electron-hole pockets, anisotropic Fermi surface, and temperature-dependent electronic structure, providing insights into its unique transport properties.

Contribution

It provides the first detailed angle-resolved photoelectron spectroscopy analysis linking electronic structure features to magnetoresistance in WTe₂.

Findings

Electron and hole pockets are nearly equal in size at the Fermi level.

The Fermi surface is highly anisotropic and quasi one-dimensional.

Temperature induces changes in the Fermi surface and conduction behavior.

Abstract

The electronic structure basis of the extremely large magnetoresistance in layered non-magnetic tungsten ditelluride has been investigated by angle-resolved photoelectron spectroscopy. Hole and electron pockets of approximately the same size were found at the Fermi level, suggesting that carrier compensation should be considered the primary source of the effect. The material exhibits a highly anisotropic, quasi one-dimensional Fermi surface from which the pronounced anisotropy of the magnetoresistance follows. A change in the Fermi surface with temperature was found and a high-density-of-states band that may take over conduction at higher temperatures and cause the observed turn-on behavior of the magnetoresistance in WTe$_2$ was identified.