LAUSR

The magnetization switching in a perpendicularly magnetized nanomagnet by applying a circularly polarized rf field is analyzed as a function of the thickness (d) of the specimen using an effective one-dimensional model. It is found that there exist two kinds of critical thicknesses, dc1 and dc2 (≥dc1). When d < dc1, the switching mode is uniform type which is well described by a macro-spin model. On the other hand, when dc1 ≤ d < dc2, the switching mode is non-uniform type, whereas the rf frequency dependence of the switching field is the same as the one with d < dc1. In the case of d ≥ dc2, the critical rf frequency at which the switching field takes a minimum value, increases. The results indicate that the switching field is more effectively reduced than the conventional microwave-assisted switching.