Effect of Bloch Lines on Magnetic Domain-Wall Mobility

Certain magnetic domain walls in a garnet film show a much reduced mobility from that of normal domain walls in the film and are interpreted to contain vertical Bloch lines. Theory shows that forward wall motion involves sideways propagation of Bloch lines and that in the high Bloch-line density limit, the mobility for small $\alpha$ is reduced to ${\alpha }^2$ of the conventional value, where $\alpha$ is the Gilbert damping parameter.