Department of Applied Physics and Physico-Informatics, Keio University, Yokohama 223-8522, Japan.
Center for Quantum Spintronics, Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway.
Phys Rev Lett. 2018 Jul 6;121(1):017202. doi: 10.1103/PhysRevLett.121.017202.
We report the observation of the intrinsic dampinglike spin-orbit torque (SOT) arising from the Berry curvature in metallic-magnet/CuO_{x} heterostructures. We show that a robust dampinglike SOT, an order of magnitude larger than a fieldlike SOT, is generated in the heterostructure despite the absence of the bulk spin-orbit effect in the CuO_{x} layer. Furthermore, by tuning the interfacial oxidation level, we demonstrate that the fieldlike SOT changes drastically and even switches its sign, which originates from oxygen-modulated spin-dependent disorder. These results provide important information for a fundamental understanding of the physics of the SOTs.
我们报告了在金属磁体/CuO_{x}异质结构中观察到的源于 Berry 曲率的固有类阻尼自旋轨道扭矩(SOT)。我们表明,尽管 CuO_{x}层中不存在体自旋轨道效应,但在异质结构中仍会产生比类磁场 SOT 大一个数量级的稳健类阻尼 SOT。此外,通过调节界面氧化程度,我们证明了场 SOT 会发生剧烈变化,甚至会改变其符号,这源于氧调制的自旋相关无序。这些结果为理解 SOT 物理提供了重要信息。