Focused He⁺ Ion Irradiation for Deterministic Nanoscale Domain Wall Pinning and Domain Nucleation in Current-Driven Magnetization Switching.

Predictive domain wall nucleation, propagation, and pinning is achieved by He⁺ ion irradiation of spin-orbit torque thin film devices. Engineering the magnetic anisotropy landscape with nm precision, we demonstrate that non-irradiated gaps as small as 10 nm can act as reliable pinning sites, highlighting the potential of this method for device miniaturization. We also create artificial nucleation centers, enabling deterministic control of the switching process and subsequent reversal propagation. This study presents a simple and effective strategy for advancing nanoscale design of energy-efficient domain wall memory and logic devices.