A register having a track with a first electrode is at the first end to
supply a current to the track in a first direction and a second electrode
at the second end to supply a current to the track in a second direction,
the second direction being opposite to the first direction. A first
domain wall anchor and a second domain wall anchor are positioned
proximate the track between the first electrode and the second electrode.
Each of the domain wall anchors has a ferromagnetic pinned layer and a
barrier layer proximate the track, with the barrier layer between the
track and the ferromagnetic pinned layer. The ferromagnetic layer has a
magnetization orientation pinned perpendicular to the magnetization
orientation of the track.