Multiple-Step Relaxing-Precessional Magnetization Switching

Spin-transfer-torque-induced multiple-step magnetization switching in a spin valve with a perpendicular polarizer subjected to an inplane magnetic field has been investigated by macrospin simulation. The single-step, triple-step, and double-step reversals are observed at a certain range of the bias field angle and of the current density. With the larger injected current, the angular range of the triple-step reversal becomes much wider. For a given magnetic anisotropy, there is a critical value for the spin-transfer torque, above which the triple-step magnetization switching disappears, and double-step one appears.