Perturbation Theory Based on the Riemann Problem for the Landau-lifshitz Equation
نویسنده
چکیده
Soliton solutions of the perturbedLandau-Lifshitz equation, S t = [S × Sxx ] + [S × JS] + ER(S), c being a small parameter, describing the nonlinear dynamics of the magnetization field in a one-dimensional ferromagnet with a biaxial anisotropy, are analysed. Perturbation theory based on the Riemarm problem is constructed for studying the influence of small perturbations on the dynamics of domain walls and magnetic solitons. The perturbation-induced magnetization dynamics is considered for some physically important perturbations. In particular, we describe the interaction of the domain wall with an impurity taking into account the dissipation in the presence of an external magnetic field, and also obtain laws for radiative and dissipative damping of a small-amplitude magnetic soliton. The threshold value of the external magnetic field for fusion of two domain walls with opposite polarities into a magnetic soliton is calculated too.
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