DOM: The simulation of flexible magnetic bubbles

A numerical model for the simulation of the dynamics and deformations of thin film magnetic domains in magnetic bubble devices is described. The motions of the domain walls are calculated from the total effective magnetic field acting on them; the total field includes the equivalent field of the wall energy, the demagnetizing fields, the bias field, and the nonuniform fields from conductors or other sources. The numerical scheme of time integration of the wall motion is described; the simulated time step is adaptively optimized in the presence of incipient numerical instabilities, which are monitored by means of Fourier transformations. The model was used to investigate collapse and runout of free bubbles and stripeout and replication of domains under current carrying conductors. The results presented show agreement with experimental data.