Thermal effects on spin-torque-driven switching in high-tunneling-magnetoresistance magnetic tunnel junctions

This paper presents a micromagnetic study of the spin-transfer torque induced, thermally assisted switching, in magnetic tunnel junctions. Having performed numerous repeated simulations, we confirm that temperature fluctuations facilitate reversal processes. In particular, different averaging procedures were employed in order to separate pure thermal effects from other contributions. The results indicate that the finite temperature introduces well-defined pre and postswitching oscillation modes and thus, the "incubation delay" is not observed for the simulated device. Detailed analysis of the preswitching oscillations, for both the antiparallel to parallel and parallel to antiparallel transitions, reveals that the oscillations in the center of the sample are the dominating mode. The excitation of these central modes is the main mechanism leading to earlier switching, especially at current densities below the critical ones computed at T = 0 K .