Magnetic domain wall propagation velocity in nanowires at high field

Based on energy conservation principle, a proper definition of domain wall (DW) propagation velocity is obtained. Furthermore, a new formula of high-field magnetic DW propagation velocity is derived. This formula agrees well with both experiments and OOMMF simulations. Different from the usual Walker´s high field velocity formula whose asymptotical linear field-dependence pass through the origin, the asymptotical linear field-dependence of the new formula does not pass through the origin, in agreement with both experimental and numerical observations.