Room temperature spin Hall effect in graphene/MoS$_2$ van der Waals heterostructures

TL;DR

This study demonstrates room temperature spin Hall effect in graphene/MoS2 heterostructures, enabling efficient spin-to-charge conversion and advancing potential spintronic device applications using two-dimensional materials.

Contribution

First experimental demonstration of room temperature spin Hall effect in graphene induced by MoS2 proximity, revealing enhanced spin-to-charge conversion efficiency.

Findings

Spin Hall effect observed up to room temperature.

Superimposed spin-to-charge conversion mechanisms identified.

Theoretical analysis supports spin Hall effect in MoS2 as primary cause.

Abstract

Graphene is an excellent material for long distance spin transport but allows little spin manipulation. Transition metal dichalcogenides imprint their strong spin-orbit coupling into graphene via proximity effect, and it has been predicted that efficient spin-to-charge conversion due to spin Hall and Rashba-Edelstein effects could be achieved. Here, by combining Hall probes with ferromagnetic electrodes, we unambiguously demonstrate experimentally spin Hall effect in graphene induced by MoS$_2$ proximity and for varying temperature up to room temperature. The fact that spin transport and spin Hall effect occur in different parts of the same material gives rise to a hitherto unreported efficiency for the spin-to-charge voltage output. Remarkably for a single graphene/MoS$_2$ heterostructure-based device, we evidence a superimposed spin-to-charge current conversion that can be indistinguishably associated with either the proximity-induced Rashba-Edelstein effect in graphene or the spin Hall effect in MoS$_2$. By comparing our results to theoretical calculations, the latter scenario is found the most plausible one. Our findings pave the way towards the combination of spin information transport and spin-to-charge conversion in two-dimensional materials, opening exciting opportunities in a variety of future spintronic applications.