Modeling on current-induced multiple domain-wall motion in permalloy nanowires

We performed micromagnetic modeling on moving multiple data bits (4 to 64 bits) in permalloy nanowires and investigated the important factors affecting domain-wall movement. It was observed that current-driven multiple transverse domain walls motion (MTDWM) in cylindrical nanowires with a diameter below 20nm is characteristic of an exceptional massless mobility, which is independent of the number of bits. Besides, two phenomena are noteworthy: First, the linear velocity and the domain-wall width are closely related to the diameter of a wire. Second, the domain walls collapse when the wire diameter is more than 30 nm.