Spin Hall effect and Weak Antilocalization in Graphene/Transition Metal Dichalcogenide Heterostructures

TL;DR

This theoretical study explores the spin Hall effect and weak antilocalization in graphene/TMDC heterostructures, revealing how disorder and material choice influence spin transport and providing guidelines for optimizing spintronic device performance.

Contribution

The paper introduces a detailed theoretical analysis of spin Hall and weak antilocalization effects in graphene/TMDC heterostructures using realistic models, highlighting the impact of disorder and material selection.

Findings

Graphene/WS2 maximizes spin proximity effects.

Disorder suppresses spin Hall signals.

Stronger WAL correlates with weaker charge-to-spin conversion.

Abstract

We report on a theoretical study of the spin Hall Effect (SHE) and weak antilocal-ization (WAL) in graphene/transition metal dichalcogenide (TMDC) heterostructures, computed through efficient real-space quantum transport methods, and using realistic tight-binding models parametrized from ab initio calculations. The graphene/WS 2 system is found to maximize spin proximity effects compared to graphene on MoS 2 , WSe 2 , or MoSe 2 , with a crucial role played by disorder, given the disappearance of SHE signals in the presence of strong intervalley scattering. Notably, we found that stronger WAL effects are concomitant with weaker charge-to-spin conversion efficiency. For further experimental studies of graphene/TMDC heterostructures, our findings provide guidelines for reaching the upper limit of spin current formation and for fully harvesting the potential of two-dimensional materials for spintronic applications.