Patent ID: 8537506

Claim:
An information storage device comprising: a magnetic track having a plurality of magnetic domains and a magnetic domain wall between each pair of adjacent magnetic domains; a magnetic domain wall moving unit configured to move at least the magnetic domain wall; and a magneto-resistive device configured to read information recorded on the magnetic track, the magneto-resistive device including, a pinned layer having a fixed magnetization direction, a free layer disposed between the pinned layer and the magnetic track, and having a magnetization easy axis that is non-parallel to the fixed magnetization direction of the pinned layer, and a separation layer between the pinned layer and free layer, wherein a magnetization direction of the free layer and the fixed magnetization direction of the pinned layer are configured to change between a semi anti-parallel state and a semi parallel state when the magneto-resistive device reads the information, the semi-anti-parallel state being a state in which there is an obtuse angle between the magnetization direction of the free layer and the fixed magnetization direction of the pinned layer, and the semi parallel state being a state in which there is an acute angle between the magnetization direction of the free layer and the fixed magnetization direction of the pinned layer.