Magnetic skyrmions are a class of nanoscale magnetic structures with non-trivial topological textures, featuring both topological stability and geometric deformability. Beyond topological charge, the morphology and helicity of skyrmions serve as critical degrees of freedom that govern their interactions, dynamical behaviors and device functionalities. Geometric confinement modulates local energy landscapes via boundary conditions, providing an effective pathway to tailor the morphology and collective behaviors of skyrmions. In dipole-stabilized systems or chiral magnets with isotropic Dzyaloshinskii-Moriya interaction (DMI), geometric confinement generally manifests as anisotropic constraints on skyrmion morphology, with negligible sensitivity to helicity. In contrast, the anisotropic DMI in D2d or S4 symmetric magnets exhibits directional dependence and can stabilize anisotropic elliptical skyrmions with distinct helicities. While geometric confinement can reshape skyrmion morphology, how it cooperates with anisotropic DMI to drive helicity-dependent variations in ellipticity and induce emergent magnetic structures remains a pivotal scientific question to be addressed.
To tackle this challenge, the teams led by Professor Yanglong Hou and Research Professor Licong Peng from the School of Materials Science and Engineering, Peking University, in collaboration with researchers from the High Magnetic Field Laboratory of the Hefei Institutes of Physical Science at the Chinese Academy of Sciences, the School of Physics of Peking University, Shanxi Normal University and Sun Yat-sen University, have revealed the helicity-dependent confinement effect on the ellipticity of anisotropic skyrmions in FeNiPdP nanoribbons and observed confinement-induced interstitial surface vortices. The findings were obtained through a combination of room-temperature in-situ external field manipulation via Lorentz transmission electron microscopy (L-TEM), automated image analysis, analytical modeling and micromagnetic simulations. Titled Helicity-Dependent Ellipticity and Interstitial Vortices in Confined Anisotropic Skyrmions, the related work was published online in Advanced Materials on September 30, 2026.
https://doi.org/10.1002/adma.75203
