Study of spin-orbit torques in magnetic bilayer

In recent years, the spin-orbit interaction in magnetic/nonmagnetic bilayer has attracted intensive attention, which opens a new path to electrically control magnetism. The spin-orbit interaction describes the coupling between electron charge and spin, which is the fundamental building block of magnetism. It is found that an in-plane current through the bilayer can generate a spin-orbit torque that manipulates the magnetization of the magnetic layer [1,2]. The efficiency of this effect mainly depends on the property of the nonmagnetic layer, which is typically stronger in materials with strong spin-orbit interactions. In this talk I will review the recent development and discuss about some controversies in this field. I will also present our recent efforts on the accurate detection of the spin-orbit torque [3].\\[4pt] [1] Liu, L.\textit{ et al.} Spin-Torque Switching with the Giant Spin Hall Effect of Tantalum. \textit{Science} \textbf{336}, 555-558 (2012).\\[0pt] [2] Miron, I. M.\textit{ et al.} Perpendicular switching of a single ferromagnetic layer induced by in-plane current injection. \textit{Nature} \textbf{476}, 189-U188 (2011).\\[0pt] [3] Fan, X. \textit{et al.} Quantifying interface and bulk contributions to spin--orbit torque in magnetic bilayers. \textit{Nature Communications }\textbf{5}, 3042 (2014)