High Domain Wall Velocity at Zero Magnetic Field Induced by Low Current Densities in Spin Valve Nanostripes

Current-induced magnetic domain wall motion at zero magnetic field is observed in the permalloy layer of a spin-valve-based nanostripe using photoemission electron microscopy. The domain wall movement is hampered by pinning sites, but in between them high domain wall velocities (exceeding 150 m/s) are obtained for current densities well below 10 12 A/m 2 , suggesting that these trilayer systems are promising for applications in domain wall devices in case of well controlled pinning positions. Vertical spin currents in these structures provide a potential explanation for the increase in domain wall velocity at low current densities.