Temperature effect on lattice and electronic structures of WTe$_2$ from first-principles study

TL;DR

This study uses first-principles calculations to analyze how temperature affects the lattice and electronic structures of WTe$_2$, revealing that thermal expansion is not responsible for the temperature-dependent magnetoresistance.

Contribution

It provides a detailed first-principles analysis of temperature effects on WTe$_2$, highlighting the anisotropic thermal expansion and its limited impact on electronic properties.

Findings

Thermal expansion coefficients are highly anisotropic and large.

Temperature below 300 K has negligible effect on the Fermi surface.

Thermal expansion is not the main cause of magnetoresistance decrease.

Abstract

Tungsten ditelluride (WTe$_2$) exhibits extremely large and unsaturated magnetoresistance (MR). Due to the large spatially extensions of Te-5p and W-5d orbitals, the electronic properties of WTe$_2$ are sensitive to the lattice structures, which can probably affect the strongly temperature dependent MR found in experiment. Based on first-principle calculations, we investigate the temperature effect on the lattice and electronic structures of WTe$_2$. Our numerical results show that the thermal expansion coefficients of WTe$_2$ are highly anisotropic and considerably large. However, the temperature (less than 300 K) has ignorable effect on the Fermi surface of WTe$_2$. Our theoretical results clarify that the thermal expansion is not the main reason of the temperature-induced rapid decrease of magnetoresistance.