Short-Range Interactions of Domain Walls in Ferromagnetic Nanostripes

Collisions of slowly moving domain walls (DWs) of the transverse and vortex types are analytically studied within the XY approximation. The previously reported effects of the mutual DW annihilation and of the formation of stable 2 π-DWs (a “topological repulsion”) are explained on the basis of a very general mechanism connected to the creation or annihilation the vortex-antivortex pairs.