Mechanism of field-like torque in spin-orbit torque switching of perpendicular magnetic tunnel junction

The current-induced spin-orbit torque (SOT) is one of the most promising ways for high speed and low power spintronics devices. However, the mechanism of SOT driven magnetization reversal, especially the role of the field-like torque (FLT), is still unclear. Here, we report the observed promotion and suppression of switching by FLT, which depends on the relative direction of FLT and spin polarization. Our results reveal that the FLT could modulate the switching speed and power consumption by affecting the work done by the damping-like torque, and leads two different reversal dynamical paths during the switching. Furthermore, the origin of incubation time in SOT induced switching is clarified simultaneously.