All-optical magnetization switching in ferrimagnetic alloys:   deterministic vs thermally activated dynamics
  Using photo-emission electron microscopy with X-ray magnetic circular dichroism as a contrast mechanism, new insights into the all-optical magnetization switching (AOS) phenomenon in GdFe based rare-earth transition metal ferrimagnetic alloys are provided. From a sequence of static images taken after single linearly polarized laser pulse excitation, the repeatability of AOS can be measured with a correlation coefficient. It is found that low coercivity enables thermally activated domain wall motion, limiting in turn the repeatability of the switching. Time-resolved measurement of the magnetization dynamics reveal that while AOS occurs below and above the magnetization compensation temperature $T_\text{M}$, it is not observed in GdFe samples where $T_\text{M}$ is absent. Finally, AOS is experimentally demonstrated against an applied magnetic field of up to 180 mT. 
L. Le Guyader and S. El Moussaoui and M. Buzzi and M. Savoini and A.   Tsukamoto and A. Itoh and A. Kirilyuk and Th. Rasing ...
cond-mat.mtrl-sci