MURPHYS-HSFS-2014 - 7th International Workshop on Multi-Rate Processes & Hysteresis, 2nd International Workshop on Hysteresis and Slow-Fast Systems, April 7-11, 2014 - Abstract
with G. Bertotti and C. Serpico
A jump-noise process is introduced in nonlinear magnetization dynamics equation to account for random thermal effects. It is demonstrated that that Landau-Lifshitz and Gilbert damping terms emerge as average effects caused by the jump-noise process. In the case of spintronics, the spin-torque term can be also derived by using this approach. Thermal effects (damping and fluctuations) occur on a much longer time-scale than deterministic precessions. For this reason, the averaging technique can be used to reduce the random magnetization dynamics to stochastic processes on graphs for magnetic energy. Applications to low temperature random switching is discussed and demonstrated that the developed approach leads to the results which are usually attributed to the phenomena of “macroscopic tunneling” of magnetization.