Ultrafast switching of a spin valve with perpendicular anisotropy

The switching properties of a spin valve with perpendicular anisotropy is investigated in terms of the fully relativistic screened Korringa-Kohn-Rostoker method, the corresponding Kubo-Greenwood equation of electric transport, and the Landau-Lifshitz-Gilbert equation. In excellent agreement with very recent experimental data, it is found that (a) the inverse of the switching time is linear with respect to the critical current, (b) the ratio of critical currents for switching from parallel (P) to antiparallel (AP) and from AP to P is about 2, and (c) the tiny magnetoresistance found in experiment is a consequence of the perpendicular anisotropy.