A compact model of domain wall propagation for logic and memory design

Current-driven domain wall motion is very promising for low-power, high-density, and high-speed circuits. By combining this shifting scheme with magnetic tunnel junction (MTJ) for reading and writing processes, it opens new routes for nonvolatile logic and memory applications that are crucial for the future of spintronics. This paper reports on a compact model for domain wall-MTJ-based circuit design, simulation, and evaluation. It integrates spin transfer torque mechanism for magnetization reversal and domain wall nucleation, current-driven domain wall pinning/motion behaviors, and tunnel resistance theory of MTJ nanopillar, in which the free layer is one storage element of magnetic stripe. This model is programmed with a very flexible structure to achieve the best simulation precision and efficiency, and provide easy parameter configuration interface. It is compatible with classical computer-aided design environment and can be cosimulated directly with CMOS design kits. By using the compact model, we have successfully simulated a domain wall propagation shift register.