Effective Dynamics in Ferromagnetic Thin Films

with Weinan E


In a ferromagnetic material, the dynamics of the relaxation process is affected by the presence of a strong shape or material anisotropy. In this paper, we systematically explore this fact to derive the effective dynamical equation for a soft ferromagnetic thin film. We show that as a consequence of the interplay between shape anisotropy and damping, the gyromagnetic term is effectively also a damping term for the in-plane components of the magnetization distribution. We validate our result through numerical simulation of the original Landau-Lifshitz equation and our effective equation.

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Comparison of the full Landau-Lifshitz Dynamics and the Effective Dynamics:

The following are some of the simulations we have performed to assess the validity of our effective equation. We have performed numerical simulations of the full Landau-Lifshitz equation and our effective equation, with and without an appied field, and compared them for several different values of the aspect ratio.
Carlos Garcia Cervera