Magnetic skyrmion arrangement tuning by surface acoustic waves.

Skyrmions, as nonlinear topological solitons, have garnered significant attention due to their unique physical properties and promising potential for applications. However, achieving controlled manipulation of skyrmion arrays remains a formidable challenge. Here, we introduce a SAW-mediated strategy to engineer well-ordered skyrmion configurations within ferromagnetic [Co/Pd]n multilayer nano-islands. We exploit radially propagating SAWs generated by fan-shaped interdigital transducers to achieve controlled spatial ordering of skyrmions. The ordering arises from SAW-induced anisotropic strain gradients, which create periodically modulated potential landscapes. Quasi-static analysis reveals the critical role of magnetoelastic coupling, enabling strain-amplitude-dependent lattice transitions and wavelength-selective ordering. Furthermore, pulsed SAWs implement a neuromorphic synapse-inspired design emulating long-term potentiation, achieving 94.6% accuracy on CIFAR-10. This work not only provides an effective strategy for controlling skyrmion arrangement in confined nano-islands but also offers valuable insights for the device integration of skyrmions.