Computer simulation of magnetic domain wall motion to derive effective interaction forces between vertical Bloch lines

Magnetization configurations of a planar domain wall containing vertical Bloch lines (VBL´s) were calculated using equations of wall motion which were extended to include wall-demagnetizing field originating from the magnetic charges around the VBL´s. The wall was given initial configuration defined appropriately and left to be relaxed under an inplane field applied tangentially until the VBL´s almost ceased to move. Because of the introduction of the magnetostatic interaction the VBL´s were observed to attract each other to make a cluster. The derivation of the magnetostatic force terms in the equations of wall motion, methods of numerical calculation, and results obtained for two to four clustered VBL´s are given.