Motion of transverse domain walls in thin magnetic nanostripes under transverse magnetic fields

Abstract

The motion of transverse magnetic domain walls (TDW) in thin magnetic nanostripes under transverse magnetic fields (TMF) is investigated. In the absence of axial fields, an approximate static TDW profile is obtained under a TMF with an arbitrary orientation. This profile becomes exact if the TMF is parallel or perpendicular to the stripe plane. Under nonzero axial fields, the TDW becomes asymmetric and twisted, and it moves along the wire axis with two different propagation modes, rigid-body mode and precession mode, depending on the strength of the axial field. The critical strength separating these two modes is called modified Walker limit HW′. The TMF dependence of HW′, the TDW velocity and maximum twisting angle at HW′ were investigated both numerically and analytically. Moreover, it is shown that an early proposed velocity-field relationship fits well to the average velocities of a TDW above HW′. These results should be important for future developments of magnetic nanodevices based on DW propagation.