Ultrafast Laser-Induced Nucleation and Control of Magnetic Skyrmions in Magnetic Thin Films.

Magnetic skyrmions have emerged as promising candidates for next-generation nanomagnetic devices owing to their stability, nanoscale size, and efficient manipulability. In this work, we demonstrate the deterministic creation of skyrmions using a single ultrafast laser pulse in a thin ferromagnetic film. Through micromagnetic simulations, we model the effect of a focused picosecond laser pulse on a Pt/Co-based multilayer with interfacial Dzyaloshinskii-Moriya interaction (DMI). We find that above a threshold laser fluence, or equivalently, a critical pulse duration, a stable 25 nm Néel-type skyrmion diameter is created at low temperature under a modest out-of-plane magnetic field. Our results demonstrate that skyrmions can be written deterministically by a single picosecond laser pulse, eliminating the need for multiple exposures or electrical stimuli. This work systematically identifies the ultrafast excitation and material-parameter ranges that enable stable solitary skyrmion nucleation in experimentally realistic magnetic multilayers. This can be a foundation for photonic-spintronic integration, enabling optical data writing and magnetic storage, offering a pathway toward ultrafast, energy-efficient, and contactless control of topological spin states for future memory and logic applications.