Dynamics of Stripe Domain Walls in Bubble Films

Computer simulations of the dynamic behavior of domain walls in bubble films, for use in the development of the different functions of Bloch line memories, are commonly based on the domain wall model developed by Slonczewski. To investigate the degree of reliability of this wall model, we compared numerical results of the dynamics of an infinitely long, straight stripe domain with stripe translation measurements, where drive pulses of the order of 2 to 10 Oe and 50 to 200 nsec were applied, and the total displacement of the stripe, including overshoot, was measured. Numerical and experimental results for the total displacement agree well for drive fields below the experimentally determined breakdown field. The values obtained for the breakdown field also agree well in most cases; however, the discrepancy increases with increasing film thickness and drive field strength. Another discrepancy is the numerical result of a strong dependence of the stripe velocity on the drive field after breakdown in the case of thicker films, which was not observed in experiments. Both discrepancies are thought to result from implicit limitations of the wall model.