Engineering of magnetic domain walls via antidot geometry for advanced multi-state memory applications

Understanding and controlling domain wall (DW) dynamics is pivotal for the development of racetrack memory and spintronic logic devices. This study presents a comprehensive micromagnetic investigation into DW pinning and depinning in in-plane magnetized nanowires featuring circular antidots. The effects of antidot radius, current density, and saturation magnetization (M-s) on DW motion is systematically analyzed. Results reveal critical thresholds for depinning, nonlinear velocity profiles, and non-monotonic responses to antidot size highlighting the interplay between spin-transfer torque and geometric confinement. Additionally, a multi-bit-per-cell memory concept is demonstrated using graded antidot arrays, where current-controlled DW progression encodes discrete magnetic states. These findings offer design guidelines for robust and efficient domain wall manipulation in future high-density spintronic devices.