Magnetization switching of an MgO/Co/Pt layer by in-plane current injection

We demonstrate magnetization switching of a perpendicularly magnetized MgO/Co/Pt trilayer by application of an in-plane current and a constant in-plane magnetic field of small amplitude. Switching occurs due to an effective torque generated by spin-orbit coupling intrinsic to the trilayer structure. We investigate the dependence of the critical switching current on the current pulse width, showing that magnetization reversal in the dc limit is assisted by thermal fluctuations.