Emerging Multidimensional Real-Space Topological Structures at Chiral Bound States in the Continuum
Abstract
As widely studied topological singularities, bound states in the continuum (BICs) have revealed rich physical properties through their momentum-space topology. Here, we reveal and experimentally demonstrate that magnetically induced chiral BICs possess multidimensional topological structures extending into real space. We design and realize a gyromagnetic photonic crystal slab where magnetic field breaks the time-reversal symmetry and lifts the degeneracy of BICs, creating a pair of chiral BICs with opposite circular polarizations. Near-field scanning measurements reveal phase vortices with quantized topological charges, spatially distributed near-field chirality, and skyrmionic Stokes textures arising from magnetic control. Our work unveils a previously unexplored dimension of BIC topology and establishes gyromagnetic photonic crystals as versatile platforms for manipulating complex topological states.
Cite
@article{arxiv.2602.22634,
title = {Emerging Multidimensional Real-Space Topological Structures at Chiral Bound States in the Continuum},
author = {Xingqi Zhao and Jingguang Chen and Jiajun Wang and Lixi Rao and Wenzhe Liu and Fang Guan and C. T. Chan and Lei Shi and Jian Zi},
journal= {arXiv preprint arXiv:2602.22634},
year = {2026}
}