Hydrogen Evolution Driven by Photoexcited Entangled Skyrmion on Perovskite Ca₂NaNbO₃ Nanosheet

A magnetic skyrmion is a topologically stable state with potential applications for realizing the next-generation spintronic devices. Here, we demonstrate the real-space observation of skyrmions in Dion-Jacobson phase perovskite, Ca₂NaNbO₃^- (CNNO), nanosheets by using optical injection. The CNNO₄ and CNNO₆ nanosheets exhibit weak ferromagnetics, while the CNNO₅ nanosheet is superparamagnetic. The magnetic skyrmion can be clearly observed in those 2D nanosheets in the absence of the external magnetic field. First-principles calculations and micromagnetic simulations predict that the magnetic skyrmions in CNNO nanosheets is Néel-type with a diameter of 11-15 nm, in corresponding to the experiments. Our findings provide insights for developing room-temperature skyrmions in CNNO nanosheets for skyrmionic water-splitting performance in future energy generation and quantum computing devices.