Nonlinear dynamics of the magnetization in an anisotropic ferromagnet with a magnetic field.

Abstract

Introducing a particular parameter in the equations of motion for the magnetization in an anisotropic ferromagnet with a magnetic field, the Lax equations for Darboux matrices are generated recursively, the Jost solutions are satisfied the corresponding Lax equations, and the nonlinear dynamics of the magnetization are investigated. The results show that the solitary waves depend essentially on two velocities which describe a spin configuration deviating from a homogeneous magnetization. The center of inhomogeneity moves with a constant velocity, while the shape of solitary waves also changes with another velocity. The depths and widths of surface of solitary waves vary periodically with time, meanwhile its shapes are not symmetrical with respect to the center. The z component of the total magnetic moment and the total magnetic moment are not constants. The asymptotic behavior of multisoliton solutions is also analyzed.