Effects of disorder on the quantum transport properties in topologically nontrivial metal PbTaSe$_{2}$

TL;DR

This study investigates how increasing disorder affects quantum transport in the topologically nontrivial metal PbTaSe$_{2}$, revealing a transition from weak antilocalization to quadratic magnetoresistance.

Contribution

It demonstrates the impact of controlled disorder on WAL and magnetoresistance in PbTaSe$_{2}$, highlighting the role of disorder in topological quantum transport.

Findings

WAL observed in pristine PbTaSe$_{2}$ due to topologically protected backscattering

Disorder induces a transition from WAL to linear and then quadratic magnetoresistance

Disorder significantly influences quantum transport properties in topological materials

Abstract

Weak antilocalization (WAL), an increase in the electrical conductivity at low temperatures associated with the suppression of electron localization due to quantum interference effects, is often observed in topological materials. In this study, we report the observation of WAL in topologically nontrivial metal PbTaSe$_{2}$ at low temperatures. In the pristine sample, we identified the presence of WAL, which is attributed to the topologically protected backscattering. In order to investigate the influence of disorder on the WAL, we successively introduced controlled amounts of disorder by H$^{+}$-irradiation. As disorder increases, the dip-like magnetoresistance caused by WAL changes to a linear magnetoresistance(MR), and eventually to a quadratic MR as the electronic system becomes highly localized. This research unveils the significance of disorder in shaping the quantum transport characteristics of topological materials.