Intervalley Scattering and Localization Behaviors of Spin-Valley Coupled Dirac Fermions

TL;DR

This paper investigates how intervalley and intravalley scattering affect quantum transport in spin-valley coupled Dirac materials, providing insights for valleytronics applications and measurement techniques.

Contribution

It distinguishes between intervalley and intravalley scattering effects on quantum conductivity, enabling estimation of scattering rates in monolayer transition metal dichalcogenides.

Findings

Quantum conductivity corrections reveal scattering types.

Transport measurements can estimate intervalley scattering rates.

Results applicable to various multivalley Dirac systems.

Abstract

We study the quantum diffusive transport of multivalley massive Dirac cones, where time-reversal symmetry requires opposite spin orientations in inequivalent valleys. We show that the intervalley scattering and intravalley scattering can be distinguished from the quantum conductivity that corrects the semiclassical Drude conductivity, due to their distinct symmetries and localization trends. In immediate practice, it allows transport measurements to estimate the intervalley scattering rate in hole-doped monolayers of group-VI transition metal dichalcogenides (e.g., molybdenum dichalcogenides and tungsten dichalcogenides), an ideal class of materials for valleytronics applications. The results can be generalized to a large class of multivalley massive Dirac systems with spin-valley coupling and time-reversal symmetry.