  The domain wall induced reversal dynamics in compressively strained GaMnAs
was studied employing the magneto-optical Kerr effect and Kerr microscopy. Due
to the influence of an uniaxial part in the in-plane magnetic anisotropy
(90+/-Delta) domain walls with considerably different dynamic behavior are
observed. While the (90+Delta) reversal is identified to be propagation
dominated with a small number of domain walls, the case of (90-Delta) reversal
includes the nucleation of many domain walls. The domain wall
nucleation/propagation energy for both transitions are estimated using model
calculations from which we conclude that single domain devices can be
achievable using the (90+Delta) mode.
