Enhanced spin-orbit torque by interfacial Rashba-Edelstein effect in an all-oxide epitaxial heterostructure

Manipulation of local magnetization with spin-orbit torque (SOT) is a promising technology due to its minimal electromagnetic interference and fast response. Improving SOT efficiency is highly desired for energy conservation and device reliability. The interface of non-magnetic/magnetic structure provides an ideal arena for improving the SOT efficiency, as it has a crucial bearing on the Rashba-Edelstein effect and spin current tunneling. Here, we present an all-oxide device for room temperature SOT-induced magnetization switching, wherein a 2 nm NiO intercalation leads to a substantial increase of 51% in damping-like torque efficiency. The enhanced spin current source from the interfacial Rashba effect is the main driver of this phenomenon, and the magnon current serves as an efficient transport medium for spin angular momentum. These findings facilitate the application of energy-efficient and reliable in-memory computing spintronic devices. Spin orbit torque (SOT) can be used as a tool for magnetisation switching in ferromagnetic materials and can be used to control the properties of devices such as magnetoresistive random-access memory. Here, the authors experimentally report an all-oxide heterostructure device that achieve room temperature SOT-induced magnetisation switching. Using DFT calculations they identify the Rashba-Edelstein effect as playing an important role in the observed properties.