Nelineynaya dinamika geyzenbergovskogo ferromagnetika na poluosi

The nonlinear dynamics of a semi-infinite isotropic ferromagnet with partial spin pinning at the sample edge, as well as in the limiting cases of full spin pinning and in its absence, is investigated based on the Landau–Lifshitz model using the inverse scattering transform. Two types of solitons are predicted. The first of them represents magnetization oscillations with discrete frequencies, which are localized near the sample surface. The second type contains moving particle-like objects with deformable cores, which are elastically reflected from the sample boundary, whereas at large distances from the boundary they are transformed into the typical solitons of an extended ferromagnet. Peculiarities in collisions of solitons with the sample boundary are analyzed for various degrees of spin pinning on the surface. A set of new conservation laws is obtained, which guarantee the fulfillment of the required boundary conditions for solitons and ensure the localization of solitons near the sample surface or their reflection from it.