PROJECT TITLE :

Quasistatic and Pulsed Current-Induced Switching With Spin-Orbit Torques in Ultrathin Films With Perpendicular Magnetic Anisotropy

ABSTRACT:

Spin-orbit interaction derived spin torques give a means of reversing the magnetization of perpendicularly magnetized ultrathin films with currents that flow in the plane of the layers. A basic and important question for applications is that the speed and potency of switching with nanosecond current pulses. Here, we investigate and distinction the quasistatic (slowly swept current) and pulsed current-induced switching characteristics of micrometer scale Hall crosses consisting of very thin (<;one nm) perpendicularly magnetized CoFeB layers on β-Ta. Whereas complete magnetization reversal occurs at a threshold current density in the quasistatic case, short period (≤ten ns) larger amplitude pulses (≏10 times the quasistatic threshold current) lead to only partial magnetization reversal and domain formation. We associate the partial reversal with the restricted time for reversed domain growth throughout the heart beat.