Equation of motion for a domain wall movement under a nonuniform transverse magnetic field

We investigate the dynamics of the domain wall in a nonuniform field driven domain wall motion memory concept. The equation of motion for a transverse Neel-type domain wall under a nonuniform transverse magnetic field is obtained with a collective coordinate approach. The validity of the equation of the motion is confirmed with micromagnetic simulations. We find that the domain wall velocity depends on the domain wall width, Gilbert damping parameter alpha, saturation magnetization, and the gradient of the field. The domain wall velocity of similar to 100 m/s is obtained with typical material as Permalloy with a moderate field gradient (100 Oe/mu m). It has promising results for memory applications. (c) 2008 American Institute of Physics.