Crossover Between Weak Antilocalization and Weak Localization and Electron-Electron Interaction in Few-Layer WTe$_2$

TL;DR

This study investigates the interplay of weak localization, weak antilocalization, and electron-electron interactions in few-layer WTe₂, revealing a temperature-driven crossover and quantifying key quantum effects affecting its electronic properties.

Contribution

It provides the first detailed analysis of the crossover between WAL and WL in few-layer WTe₂ and quantifies the roles of EEI and SOC in its quantum transport behavior.

Findings

Observation of temperature-induced WAL to WL crossover.

Quantification of electron-electron interaction and spin-orbit coupling strengths.

Identification of characteristic lengths influencing quantum diffusive transport.

Abstract

We report electron transport studies in an encapsulated few-layer WTe$_2$ at low temperatures and high magnetic fields. The magnetoconductance reveals a temperature-induced crossover between weak antilocalization (WAL) and weak localization (WL) in quantum diffusive regime. We show that the crossover clearly manifests coexistence and competition among several characteristic lengths, including the dephasing length, the spin-flip length, and the mean free path. In addition, low temperature conductance increases logarithmically with the increase of temperature indicating an interplay of electron-electron interaction (EEI) and spin-orbit coupling (SOC). We demonstrate the existences and quantify the strengths of EEI and SOC which are considered to be responsible for gap opening in the quantum spin hall state in WTe2 at the monolayer limit.