Magnetic Domain\nWall Energy Landscape Engineering\nin a Ferrimagnet

Architectures based on a magnetic domain wall (DW) can\nstore and\nprocess information at a high speed in a nonvolatile manner with ultra-low\npower consumption. Recently, transition-metal rare earth metal alloy-based\nferrimagnets have attracted a considerable amount of attention for\nthe ultrafast current-driven DW motion. However, the high-speed DW\nmotion is subject to film inhomogeneity and device edge defects, causing\nchallenges in controlling the DW motion and hindering practical application.\nIn this work, we demonstrate a strategy for precisely engineering\nthe DW energy landscape by locally modifying the compensation state\nin a ferrimagnet via ion irradiation by using the focused ion beam\ntechnique. A diode-like DW motion behavior is observed at the lateral\njunction interface, i.e., the boundary between irradiated and non-irradiated\nCoGd, enabling selective control over DW pinning and depinning at\nspecific locations. Our work provides insight into the development\nof next-generation DW-based ferrimagnetic racetrack memory and logic\ndevices.