We study the ultra slow domain wall motion in ferromagnetic thin films driven by a weak magnetic field. Using time resolved magneto-optical Kerr effect microscopy, we access to the statistics of the intermittent thermally activated domain wall jumps between deep metastable states. Our observations are consistent with the existence of creep avalanches: roughly independent clusters with broad size and ignition waiting-time distributions, each one composed by a large number of spatio-temporally correlated thermally activated elementary events. Moreover, we evidence that the large scale geometry of domain walls is better described by depinning rather than equilibrium universal exponents.
@article{arxiv.1804.09572,
title = {Intermittent collective dynamics of domain walls in the creep regime},
author = {Matías Pablo Grassi and Alejandro B. Kolton and Vincent Jeudy and Alexandra Mougin and Sebastian Bustingorry and Javier Curiale},
journal= {arXiv preprint arXiv:1804.09572},
year = {2018}
}
Comments
Corrected and updated version. Supplementary Information included in the ancillary material