  The growing demand for storage, due to big data applications, cannot be met
by hard disk drives. Domain wall (DW) memory devices such as racetrack memory
offer an alternative route to achieve high capacity storage. In DW memory,
control of domain wall positions and their motion using spin-transfer torque
are important challenges. In this paper, we demonstrate controlled domain wall
motion using spin-transfer torque in staggered magnetic nanowires. The devices,
fabricated using electron-beam lithography, were tested using a magneto-optical
Kerr microscopy and electrical transport measurements. The depinning current,
pinning potential and thermal stability were found to depend on the device
dimensions of the staggering nanowires. Thus, the proposed staggering
configuration helps to fine-tune the properties of domain wall devices for
memory applications.
