Domain-wall-isolated dual-lane racetrack for crosstalk-free skyrmion propagation

Abstract

Magnetic skyrmions, topologically protected spin textures, are promising candidates for information carriers in metallic racetrack memories, where data bits are encoded by their spatial arrangement. Conventional skyrmion-based racetracks employ binary encoding through inter-skyrmion spacing in one-dimensional nanostrips, yet maintaining precise spacing remains challenging due to thermal fluctuations, noise, and material defects. To overcome this limitation, we propose a dual-lane racetrack architecture separated by an engineered domain wall. Micromagnetic simulations demonstrate that this design offers several critical advantages: (1) Topological repulsion from the domain wall effectively confines skyrmions to their respective lanes, eliminating cross-lane migration. (2) The motion dynamics of skyrmions in one lane exhibit minimal interference from those in the adjacent lane, owing to the topological repulsion from the domain wall that ensures a sufficiently large inter-lane spacing to weaken dipole interactions. (3) The structure enables programmable operations, including skyrmion sorting, directional transport, and controlled annihilation.