Ac and dc current-induced motion of a360°domain wall

Abstract

The response of $360\ifmmode^\circ\else\textdegree\fi{}$ domain walls in narrow magnetic stripes to applied dc and ac currents, investigated by micromagnetic simulation, differs qualitatively from the response of $180\ifmmode^\circ\else\textdegree\fi{}$ domain walls. The $360\ifmmode^\circ\else\textdegree\fi{}$ domain-wall velocity scales with a dc current but is independent of an applied magnetic field along the stripe. An annihilation process occurs at a critical dc current density that varies with the applied field. When a $360\ifmmode^\circ\else\textdegree\fi{}$ wall is perturbed, it oscillates at a characteristic frequency in the gigahertz range which is tunable by the applied magnetic field, and an ac current applied at half the characteristic frequency excites a resonant response.