Nonlinear magnetotransport shaped by Fermi surface topology and convexity in WTe2

TL;DR

This study demonstrates how Fermi surface topology and convexity influence nonlinear magnetotransport in WTe2, revealing temperature-driven inversion and anisotropy effects at room temperature, with implications for spintronics and condensed matter physics.

Contribution

It uncovers the relationship between Fermi surface shape and nonlinear magnetoresistance, supported by experimental observations and theoretical calculations in WTe2.

Findings

Room temperature nonlinear magnetoresistance observed in WTe2.

Temperature-induced inversion of nonlinear magnetoresistance.

Large anisotropy linked to Fermi surface symmetry.

Abstract

The nature of Fermi surface defines the physical properties of conductors and many physical phenomena can be traced to its shape. Although the recent discovery of a current-dependent nonlinear magnetoresistance in spin-polarized non-magnetic materials has attracted considerable attention in spintronics, correlations between this phenomenon and the underlying fermiology remain unexplored. Here, we report the observation of nonlinear magnetoresistance at room temperature in a semimetal WTe2, with an interesting temperature-driven inversion. Theoretical calculations reproduce the nonlinear transport measurements and allow us to attribute the inversion to temperature-induced changes in Fermi surface convexity. We also report a large anisotropy of nonlinear magnetoresistance in WTe2, due to its low symmetry of Fermi surfaces. The good agreement between experiments and theoretical modeling reveals the critical role of Fermi surface topology and convexity on the nonlinear magneto-response. These results lay a new path to explore ramifications of distinct fermiology for nonlinear transport in condensed-matter.