Interaction of Solitons with the Boundary of a Ferromagnetic Plate

Soliton states in a semi-infinite ferromagnetic film with partially pinned spins at its boundary are found and analyzed within the focusing nonlinear Schrödinger equation (NLSE). It is shown that solitons are divided into two classes. The first class includes magnetization oscillations with discrete frequencies localized near the film edge. The second class contains moving particle-like objects whose cores are strongly deformed at the film boundary; these objects are elastically reflected from this boundary, thus recovering the shape of solitons typical for a unbounded sample. A series of conservation laws for a wave field is obtained that ensures the localization of soliton oscillations near the boundary of the sample and the elastic reflection of moving solitons from this boundary. It is shown that a change in the phase of the internal precession of a soliton during reflection depends on the character of spin pinning at the edge of the sample.