Domain-wall step motors: Controlling the motion of magnetic domain walls using patterned magnetic films

Magnetic domain walls can move when driven by an applied magnetic field. This motion is important for numerous devices, including magnetic recording read/write heads, transformers, and magnetic sensors. A magnetic film with a sawtooth profile localizes magnetic domain walls in discrete positions at the narrowest parts of the film. We propose a controllable way to move these domain walls between these discrete locations by applying magnetic-field pulses. A similarly patterned magnetic film attached to a larger magnetic element at one end of the film can operate as an XOR logic gate.