Translational mobility of hard ferromagnetic bubbles

We show that steady translation of a magnetic bubble possessing Bloch lines requires the application of both longitudinal and transverse field gradients. The predicted longitudinal gradient obeys the usual relation valid for a normal bubble. The transverse gradient is proportional to the product of velocity and number of Bloch lines. Experiments of Tabor et al. support the theory. © 1972 The American Physical Society.