biostudies-literatureXue FNatural Science Foundation of Zhejiang Province (Zhejiang Provincial Natural Science Foundation)National Natural Science Foundation of China (National Science Foundation of China)2349https://www.ebi.ac.uk/biostudies/studies/S-EPMC11890734biostudies-literatureUnknown16(1)Polar skyrmions are topologically nontrivial polarization textures that demonstrate exotic physical phenomena and novel memory applications. Thus far, these textures have primarily been reported in oxide-ferroelectric-based epitaxial heterostructures because their stabilization requires an elastic energy penalty from the epitaxial strains. Here, without the epitaxial-strain engineering, we discover polar skyrmion bubbles in stand-alone van der Waals ferroelectric CuInP₂S₆ crystal through the combination of piezoelectric force microscopy, high-resolution transmission electron microscopy, and phase-field simulations. In a thick CuInP₂S₆ flake of over -100 nm, skyrmion bubbles feature an elliptical hedgehog-like state with center-divergent or centerNature communicationsObservation of switchable polar skyrmion bubbles down to the atomic layers in van der Waals ferroelectric CuInP<sub>2</sub>S<sub>6</sub>.PMC1189073462304202LDT23F04013F04Xue FPeng YHan PWang BHuan CMa YWang HZhang SWang JWang NZhang CWang ZZhou HSun JYuan YTong PChen PChang KTian HZheng SZhu HChen HXu HHe YYu BZhang XGao XXu YfalseObservation of switchable polar skyrmion bubbles down to the atomic layers in van der Waals ferroelectric CuInP<sub>2</sub>S<sub>6</sub>.Polar skyrmions are topologically nontrivial polarization textures that demonstrate exotic physical phenomena and novel memory applications. Thus far, these textures have primarily been reported in oxide-ferroelectric-based epitaxial heterostructures because their stabilization requires an elastic energy penalty from the epitaxial strains. Here, without the epitaxial-strain engineering, we discover polar skyrmion bubbles in stand-alone van der Waals ferroelectric CuInP₂S₆ crystal through the combination of piezoelectric force microscopy, high-resolution transmission electron microscopy, and phase-field simulations. In a thick CuInP₂S₆ flake of over -100 nm, skyrmion bubbles feature an elliptical hedgehog-like state with center-divergent or center2025-01-01T00:00:00Z2025 Mar2025-04-04T08:22:41.683Z2025-04-04T08:22:41.683ZS-EPMC118907344005753410.1038/s41467-025-57714-9