Spin-orbit torque as a method for field-free detection of in-plane magnetization switching

We proposed and demonstrated a simple method for field-free detection of in-plane magnetization switching by the spin-orbit torque (SOT) in bilayers of nonmagnetic/magnetic materials. In our method, SOT is used not only for magnetization switching but also for detection. SOT effective fields generated by an alternating reading current induce oscillation of the magnetization, which is detected via the anomalous Hall effect, planar Hall effect, anomalous Nernst effect, and spin Seebeck effect. Our method can detect arbitrary M-x and M-y components without an external magnetic field, which is useful for fast characterization of type-X, type-Y, and type-XY SOT magnetization switching. Our SOT detection scheme can be utilized not only for fast characterization of SOT switching in bilayers but also for electrical detection of in-plane magnetic domains in race-track memory.