Domain Wall Deceleration in a Ferrite–Garnet Film by Femtosecond Laser Pulses

Using a method that combines double high-speed photography and a pump-probe method, it was found that a femtosecond laser pulse is able to change the domain wall velocity in a ferrite–garnet film. The change in the velocity of the domain wall depends on both the energy of the pump pulse and the domain wall velocity itself, and does not depend on the pump pulse polarization. This result is not associated with local magnetization reversal and cannot be explained by local heating of the material, since a temperature increasing leads to an increase of the domain wall mobility. To explain the results, we propose a model in which the domain wall velocity is controlled by the photo-induced generation of vertical Bloch lines.