Non-Hermitian Topology of a Subwavelength Resonator in Synthetic Space
Abstract
Non-Hermitian singularities and the nontrivial topology of energy bands have been extensively explored in extended periodic systems, where phenomena such as exceptional points and bulk Fermi arcs are naturally associated with periodicity and momentum space. Here, we show that this non-Hermitian topology can be extended to the domain of subwavelength resonators using a synthetic space. By reconstructing the complex energy bands of a subwavelength ring resonator in the synthetic space of geometrical parameters, we experimentally observe a spectral triplet formed by two exceptional points (EPs) connected by a bulk Fermi arc and a topologically robust quasi-bound state in the continuum (q-BIC). This Fermi-arc q-BIC emerges exactly at the intersection of the bulk Fermi arc and the q-BIC line in synthetic space, establishing a direct topological link between two spectral singularities. Encircling the EPs in synthetic space visualizes the nontrivial topology of the complex energy-band structure and reveals the opposite half-integer topological charges of the EPs connected by the bulk Fermi arc. These results extend non-Hermitian topology to subwavelength structures and establish compact resonators as a versatile platform for applications in photonics, microwave physics, and acoustics.
Related
- Subwavelength exceptional points in dispersive resonator arrays
- Non-Hermitian Topology from Edge Transport in Hermitian Quantum Anomalous Hall Systems
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BibTeX
@misc{solodovchenko2026nonhermitian,
title = {{Non-Hermitian Topology of a Subwavelength Resonator in Synthetic Space}},
author = {N. Solodovchenko and F. Zhang and M. Bochkarev and K. Samusev and M. Song and M. Limonov and A. Bogdanov},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.33871},
eprint = {2610.33871},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.33871},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - Non-Hermitian Topology of a Subwavelength Resonator in Synthetic Space
AU - N. Solodovchenko
AU - F. Zhang
AU - M. Bochkarev
AU - K. Samusev
AU - M. Song
AU - M. Limonov
AU - A. Bogdanov
PY - 2026
DA - 2026/10/24
PB - arXiv
DO - 10.48550/arxiv.2610.33871
UR - https://arxiv.org/abs/2610.33871
AB - Non-Hermitian singularities and the nontrivial topology of energy bands have been extensively explored in extended periodic systems, where phenomena such as exceptional points and bulk Fermi arcs are naturally associated with periodicity and momentum space. Here, we show that this non-Hermitian topology can be extended to the domain of subwavelength resonators using a synthetic space. By reconstructing the complex energy bands of a subwavelength ring resonator in the synthetic space of geometrical parameters, we experimentally observe a spectral triplet formed by two exceptional points (EPs) connected by a bulk Fermi arc and a topologically robust quasi-bound state in the continuum (q-BIC). This Fermi-arc q-BIC emerges exactly at the intersection of the bulk Fermi arc and the q-BIC line in synthetic space, establishing a direct topological link between two spectral singularities. Encircling the EPs in synthetic space visualizes the nontrivial topology of the complex energy-band structure and reveals the opposite half-integer topological charges of the EPs connected by the bulk Fermi arc. These results extend non-Hermitian topology to subwavelength structures and establish compact resonators as a versatile platform for applications in photonics, microwave physics, and acoustics.
ER -