Gate-tunable spin Hall effect in trilayer graphene/group-IV monochalcogenide van der Waals heterostructures

TL;DR

This paper demonstrates a gate-tunable spin Hall effect in trilayer graphene coupled with SnS, a group-IV monochalcogenide, showing potential for advanced spintronic devices by leveraging proximity-induced spin-orbit coupling.

Contribution

It introduces group-IV monochalcogenides as a new class of materials to induce spin-orbit coupling in graphene, enabling gate-controlled spin Hall effects at room temperature.

Findings

Maximum spin Hall angle near charge neutrality point

Room temperature spin Hall effect observed

Proximity effect with SnS enhances spin-orbit coupling

Abstract

Spintronic devices require materials that facilitate effective spin transport, generation, and detection. In this regard, graphene emerges as an ideal candidate for long-distance spin transport owing to its minimal spin-orbit coupling, which, however, limits its capacity for effective spin manipulation. This problem can be overcome by putting spin-orbit coupling materials in close contact to graphene leading to spin-orbit proximity and, consequently, efficient spin-to-charge conversion through mechanisms such as the spin Hall effect. Here, we report and quantify the gate-dependent spin Hall effect in trilayer graphene proximitized with tin sulfide (SnS), a group-IV monochalcogenide which has recently been predicted to be a viable alternative to transition-metal dichalcogenides for inducing strong spin-orbit coupling in graphene. The spin Hall angle exhibits a maximum around the charge neutrality point of graphene up to room temperature. Our findings expand the library of materials that induce spin-orbit coupling in graphene to a new class, group-IV monochalcogenides, thereby highlighting the potential of two-dimensional materials to pave the way for the development of innovative spin-based devices and future technological applications.