Patent ID: 7667994

Claim:
A method for use with a magnetic racetrack device having given regions, the method comprising: placing domain walls having a first structure and domain walls having a second, different structure along the racetrack at stable positions corresponding to the given regions, the domain walls having the first structure and the domain walls having the second structure occupying alternating positions along the racetrack; and applying a current pulse to the racetrack, so that each of the domain walls moves to an adjacent one of the given regions, wherein: (i) the domain walls having the first structure move from regions where they have a local minimum energy to adjacent regions where the energy of domain walls having the first structure is a local maximum, with a concomitant transformation of the domain walls having the first structure into domain walls having the second structure; and (ii) the domain walls having the second structure move from regions where they have a local minimum energy to adjacent regions where the energy of domain walls having the second structure is a local maximum, with a concomitant transformation of the domain walls having the second structure into domain walls having the first structure.