Modeling and numerical studies of domain walls dynamics with pi vertical Bloch lines

We propose a model for a hard domain wall (DW) which contains closely packe d Bloch lines. Our model establishes an equivalence between DWs with differ ent numbers of Bloch lines, thus the study being equivalent to the study of a single Bloch line. The numerical investigation shows that a DW with Bloc h lines has more instabilities than a simple DW and that the mobility and t he Walker field are modified for the former in a different manner than for the latter, (C) 2000 Elsevier Science S.A. All rights reserved.