Giant antidamping orbital torque originating from the orbital Rashba-Edelstein effect in ferromagnetic heterostructures

作者：Xi Chen, Yang Liu, Guang Yang, Hui Shi, Chen Hu, Minghua Li, Haibo Zeng · 发表于：Nature Communications · 年份：2018 · DOI：10.1038/s41467-018-05057-z · 被引用次数：73 · 研究领域：Magnetic properties of thin films、Magnetic and transport properties of perovskites and related materials、Multiferroics and related materials

Abstract Enhancing the in-plane current-induced torque efficiency in inversion-symmetry-breaking ferromagnetic heterostructures is of both fundamental and practical interests for emerging magnetic memory device applications. Here, we present an interface-originated magnetoelectric effect, the orbital Rashba–Edelstein effect, for realizing large torque efficiency in Pt/Co/SiO 2 /Pt films with strong perpendicular magnetic anisotropy (PMA). The key element is a pronounced Co 3 d orbital splitting due to asymmetric orbital hybridization at the Pt/Co and Co/SiO 2 interfaces, which not only stabilizes the PMA but also produces a large orbital torque upon the Co magnetization with current injection. The torque efficiency is found to be strongly magnetization direction- and temperature-dependent, and can reach up to 2.83 at room temperature, which is several times to one order of magnitude larger than those previously reported. This work highlights the active role of the orbital anisotropy for efficient torque generation and indicates a route for torque efficiency optimization through orbital engineering.