Computer Simulation of Vertical Bloch Lines Motion

Abstract

An improved method for simulating the motion of vertical Bloch lines in a domain wall of arbitrary shape is presented together with the results on an s=0 bubble containing two Bloch lines. The formulation of a previously developed simulation program has been extended to include in-plane magnetic fields with origins both external and internal to the domain wall, so that the magnetostatic interaction between the Bloch lines may be taken into account. A numerical scheme has been devised which minimizes the total number N of points used to represent the magnetization structure along the wall by allocating them with high density only in the neighborhood of Bloch lines. The CPU time necessary to simulate a 1-μs motion with a time step of 1ns and N of 80 is about 9 minutes on a HITAC M-280H. The program is expected to become a useful tool for developing domain-wall devices utilizing Bloch lines.