Moiré Engineering of Spin-Orbit Torque by Twisted WS 2 Homobilayers.

Artificial moiré superlattices created by stacking two-dimensional crystals have emerged as a powerful platform with unprecedented material-engineering capabilities. While moiré superlattices have been reported to host a number of novel quantum states, their potential for spintronic applications remains largely unexplored. Here, we demonstrated the effective manipulation of spin-orbit torque (SOT) using moiré superlattices in ferromagnetic devices comprised of twisted WS 2 /WS 2 homobilayer (t-WS 2 ) and CoFe/Pt thin films by altering twisting angle (θ) and gate voltage. Notably, we observed a substantial enhancement of up to 44.5% in SOT conductivity at θ approximately 8.3°. Furthermore, compared to the WS 2 monolayer and untwisted WS 2 /WS 2 bilayers, the moiré superlattices in t-WS 2 enable a greater gate-voltage tunability of SOT conductivity. We related these results to the generation of interfacial moiré magnetic field by real-space Berry phase in moiré superlattices, which modulates the absorption of the spin-Hall current arising from Pt through magnetic proximity effect. This study highlights the moiré physics as a new building block for designing enhanced spintronic devices. This article is protected by copyright. All rights reserved.