Electrical control over perpendicular magnetization switching driven by spin-orbit torques

Flexible control of magnetization switching by electrical means is crucial for applications of spin orbitronics. Besides a switching current that is parallel to an applied field, a bias current that is normal to the switching current is introduced to tune the magnitude of effective damping-like and field-like torques and further electrically control magnetization switching. Symmetrical and asymmetrical control over the critical switching current by the bias current with opposite polarities is realized in both Pt/Co/MgO and α-Ta/CoFeB/MgO systems, respectively. This research not only identifies the influences of field-like and damping-like torques on the switching process, it also demonstrates an electrical method to control it.