Collective Motions Assisted by Magnetostatic Interactions in Coupled Domain Wall System

We have investigated the coupling between a transverse head-to-head domain wall and a transverse tail-to-tail domain wall in closely spaced Ni
₈₀
Fe
₂₀
nanowires. Micromagnetic simulation shows that the two domain walls are coupled to each other. When spin-polarized current is applied to any of the nanowires, the two domain walls move in the same direction. The Walker breakdown limit in such system is shifted to higher current density. We have also observed that the coupling is broken for some combinations of initial magnetizations of the two domain walls.