RADIO FREQUENCY MAGNETIZATION NONVOLATILITY

Long time magnetization thermal switching under small amplitude high frequency excitation is analyzed. Approaches based upon conventional time-dependent energy barrier are not sufficient to describe magnetization nonvolatility under GHz excitations. Methods based upon large angle nonlinear magnetization dynamics are developed for both coherent and noncoherent magnetization switching. This dynamic approach is not only important for fundamental understanding of magnetization dynamics under combined radio frequency excitations and thermal fluctuations, but also critical for practical design of emerging spintronic devices. When applied to spin torque random access memory read operations, as sensing current duration reaches nanosecond, dynamic approach gives a switching probability estimation orders of magnitude different from that obtained from conventional time-dependent energy barrier approach.