Regensburg 2013 – scientific programme
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MA: Fachverband Magnetismus
MA 14: Micromagetic Simulation and Electron Theory of Magnetism
MA 14.1: Talk
Tuesday, March 12, 2013, 09:30–09:45, H23
Notes on the Gilbert equation for dissipative magnetization dynamics — •Manfred Fähnle, Frank Schweiner, and Christian Illg — Max Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569 Stuttgart, Germany
The simplest equation of motion for dissipative magnetization dynamics M→(r→,t) close to the adiabatic limit (timescale ns - ca 100 ps) which describes precession around an effective field and damping (by a local term M→×α∂M→/∂ t with a constant damping scalar α) is Gilbert’s equation. Various types of theories have shown that in general the damping is nonlocal and anisotropic, described by a matrix α(r→,r→′;M→(r→″)) which depends on the magnetization configuration M→(r→″) at all sites r→″ in the sample. Furthermore, for very fast dynamics an inertial damping term proportional to ∂2M→/∂ t2 should be added. The Gilbert equation is a partial differential equation and has to be supplemented by boundary conditions formulated in the most general way by Guslienko and Slavin. The question is discussed whether those boundary conditions have to be applied also for numerical simulations based on Gilbert’s equation. A tensorial Green’s function is constructed for the solution of the linearized Gilbert equation.