Mean-field dynamics of the spin-magnetization coupling in ferromagnetic materials: Application to current-driven domain wall motions

In this paper, we present a mean-field model of the spin-magnetization coupling in ferromagnetic materials. The model includes non-isotropic diffusion for spin dynamics, which is crucial in capturing strong spin-magnetization coupling. The derivation is based on a moment closure of the quantum spino...

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Detalhes bibliográficos
Autores: Chen, J., García-Cervera, C.J., Yang, X.
Formato: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2015
País:España
Recursos:Basque Center for Applied Mathematics (BCAM)
Repositorio:BIRD. BCAM's Institutional Repository Data
OAI Identifier:oai:bird.bcamath.org:20.500.11824/59
Acesso em linha:http://hdl.handle.net/20.500.11824/59
Access Level:acceso abierto
Palavra-chave:magnetization dynamics
Spin dynamics
spin-magnetization coupling
Descrição
Resumo:In this paper, we present a mean-field model of the spin-magnetization coupling in ferromagnetic materials. The model includes non-isotropic diffusion for spin dynamics, which is crucial in capturing strong spin-magnetization coupling. The derivation is based on a moment closure of the quantum spinor dynamics coupled to magnetization dynamics via the Landau-Lifchitz-Gilbert equation and the spin-transfer torque. The method is general and systematic, and can be used to study spin-orbit coupling as well. The form of the non-isotropic diffusion is generic, i.e., independent of the closure assumptions. Fully 3-D numerical simulation is implemented and applied to predict current-driven domain wall motions. It shows a non-linear dependence of the wall speed on the current density, which agrees with the experiments.