Orbital-driven field-free switching in low-symmetry van der Waals heterostructures

Abstract

We develop a microscopic model for orbital-driven, field-free magnetization switching in low-symmetry van der Waals heterostructures. Using minimal tight-binding models for a 1Td transition metal dichalcogenide (TMD) interfaced with a ferromagnet (FM), we show that the low-symmetry character of the TMD is imprinted on the FM by interfacial orbital mixing, generating out-of-plane torques triggered by the orbital Rashba–Edelstein effect. Combining linear-response calculations, symmetry analysis, and magnetization dynamics simulations, we demonstrate deterministic switching of a perpendicular magnetic anisotropy state by currents of ∼5×107Acm−2, without the need for external magnetic fields. Additionally, our analysis reveals a constructive interplay between in-plane and out-of-plane torques. We obtain analytical expressions for the switching current, showing excellent agreement with the simulations. Our results suggest an orbital-driven pathway for spin–orbit torque generation and efficient magnetization control.