Numerical Calculation of Magnetic Bubble Domain Wall Motion Based on a Lumped-Constant Model of Vertical Bloch Lines

An efficient way of calculating the motion of a domain wall which may contain a number of vertical Bloch lines has been developed on the basis of a previously constructed model in which the magnetization structure distributed in a Bloch line is regarded as being concentrated at a single point on the wall. It has been found that the equations of motion derived from the model can be solved in a stable manner by using the backward Euler method. The model has the same range of application as conventional models based on the so-called equation of wall motion. The results of computer simulation show that the method saves 95% of the computation time needed with the conventional method. This paper describes the derivation of the model and the principle of the numerical methods, together with the results of computer simulation clarifying the range of application of the model.