Micromagnetic Study on Thermally Induced Magnetization Reversal of a Coupled Spin Chain System

We performed numerical studies of the dynamics of thermally induced magnetization reversal of a coupled Heisenberg spin chain, based on the stochastic Landau-Lifshitz-Gilbert equation. Special attention is given to characterizing the transitions between different switching mechanisms (e.g., coherent rotation, soliton, and multidroplet reversals), as the chain length L is increased. Our calculations reveal that the switching time, switching time distribution, and the time evolution behavior of magnetization reversal display nontrivial dependence on the chain length L, and undergo distinct transitions as a function of L. In particular, we found that the switching time distribution is an important determinant of thermal stability, in addition to the mean switching time