Current-induced collective motion of 180° and 360° domain walls in double nanowires system

Collective motion of 180° domain wall and 360° domain wall in two parallel nanowires have been investigated by micromagnetic simulation. The two domain walls are coupled to each other via magnetostatic interaction. When a spin-polarized current is only applied to one of the nanowires, two domain walls propagate along the nanowires with a same velocity, which increases linearly with the current velocity until it comes near to the current velocity limit. Simulations show that coupling of the two domain walls enhance the stability of 360° domain wall, and the critical velocity of 360° domain wall increases from 461 m/s to 723 m/s.