Universality of stochasticity in magnetic domain-wall motion

We report an experimental observation on universality of stochasticity in magnetic domain-wall motion along ferromagnetic nanowires. The domain-wall arrival time exhibits stochasticity depending on the nanowire width and strength of external magnetic field. Strikingly, all of the measured stochasticity data collapse onto a single universal curve that is given by a function of the number of de-pinning events. Such stochasticity has been found to be saturated for nanowires thinner than about 200 nm, which is possibly attributed to the dimensionality transition from two to one dimension. These results provide essential information for operating and/or design of domain-wall mediated devices. (C) 2015 The Japan Society of Applied Physics