Enhanced controllability of domain-wall pinning by selective domain-wall injection

It is experimentally reported that depinning fields of domain walls (DWs) under an interaction between magnetic charges distributed at a nanobar and at a notch can be enhanced by controlling injection fields for injecting DWs into the ferromagnetic nanowire with an asymmetrical nucleation pad. The DWs injected from the asymmetrical pad show an asymmetrical dependence of the injection field on the saturation angle and are pinned by the notch with the nanobar vertical to it. We have found that the shape of the pinning potential energy experienced by the DW is affected by the uniformly magnetized direction of the nanobar and the pinning potential energy is locally modified by selectively controlling the DW-injection. This is consistent with our estimation based on micromagnetic simulation. (C) 2013 American Institute of Physics.