Poisson's process in the propagation of magnetic domain wall in a perpendicularly magnetized film

We present here a statistical study of the transit time required for a magnetic domain wall to go through a small laser spot focused on two-dimensional magnetic thin film. The domain wall velocity deduced this way is in good agreement with the other ways used to measure this parameter, but the main fact is that the transit time is not a reproducible parameter; we have observed a quite large distribution of this parameter. This distribution can be explained assuming the movement to occur through jumps, whose probabilities are given by Poisson's process. The fitting of this distribution has enabled us to get the required number of jumps to reverse the magnetization of the small area under the laser spot. This important parameter should lead to a better understanding of the creep regime.