Magnetic Bubble Domain and Domain Wall Dynamics in Gradient Translation

The object of this work is to extend both the experimental and theoretical understanding of domain wall dynamics in magnetic bubble translation. Bubble motion in the presence of a bias field gradient has been investigated in detail, using high-speed sampling microscopy with 10 nanosecond laser pulse illumination. Transient bubble translation was observed and overshoot was confirmed. The stored momentum formulation was expanded. Creep was discovered and a qualitative model was formulated to explain the various phases of the translational motion and the mechanism of momentum storage and release. The model was further confirmed by the transverse distortion phenomenon observed 1n the high impulse gradient experiment. Equation of motion for magnetic domain walls and Bloch lines are also included.