Micromagnetic simulation of spin transfer torque switching combined with precessional motion from a hard axis magnetic field

The authors have performed micromagnetic simulations of spin transfer torque (STT) switching, combined with precessional motion induced by a pulsed or static hard axis field. They have found a significant reduction in the current required for STT switching in the presence of precessional motion. In particular, the switching current can be reduced below the zero-temperature threshold current at dc, when the hard axis field exceeds a fourth of the free layer coercivity. The simulations indicate that the critical current reduction arises from the strong STT present when the magnetization nearly passes through the hard axis during the initial few precessional turns.