Degenerate high-order hybrid bound states in the continuum beyond diffraction limit

Ji Tong Wang; Nicolae C. Panoiu

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arXiv · 2608.10125

Degenerate high-order hybrid bound states in the continuum beyond diffraction limit

Ji Tong Wang·Nicolae C. Panoiu

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Abstract

We demonstrate the existence of at-$\Gamma$ degenerate hybrid bound-states in the continuum (BICs) with high-order topological charges and quadratic band degeneracy in periodic photonic structures with $C_{6v}$ symmetry above the diffraction limit. The degenerate BICs are realized by combining symmetry protection, which suppresses radiation into zeroth-order diffraction channel, with quadratic band degeneracy and parameter tuning to eliminate radiation into first-order diffraction channels. An effective Hamiltonian is used to investigate the band structure around the degeneracy point, and the topological dynamics in all diffraction channels are characterized. This work reveals a novel mechanism for realizing degenerate BICs above the diffraction limit, opening up opportunities for new physics and applications.

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Ji Tong Wang, Nicolae C. Panoiu. 2026-08-10. Degenerate high-order hybrid bound states in the continuum beyond diffraction limit. https://arxiv.org/abs/2608.10125

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