A data storage device includes a unpatterned magnetic film having data
regions in which to store data. A track is disposed in proximity to the
magnetic film, such that the track selectively defines a shiftable
magnetic domain wall. In order to select a data bit that is stored in one
of the data regions of the magnetic film, a fringing field of the
magnetic domain wall in the track is used to selectively change a
direction of a magnetic moment in the data region.