Zero-energy modes induced by nonreciprocal hopping in photonic analogs of graphene quantum dots
Phys. Rev. B 113, 035409 – Published 6 January, 2026
DOI: https://doi.org/10.1103/bw1x-rxc3
Abstract
We theoretically investigate the interplay between nonreciprocal hopping and artificial magnetic fields in hexagonal photonic analogs of graphene quantum dots with zigzag and armchair edges. We demonstrate that nonreciprocal coupling overcomes finite-size hybridization limits, inducing robust zero-energy modes in zigzag photonic analogs of graphene quantum dots (PGQDs) even at ultracompact sizes. For armchair PGQDs, such modes—typically absent in the Hermitian limit—emerge only when the nonreciprocity exceeds a threshold. We further show that a weak synthetic magnetic field suppresses the non-Hermitian skin effect by counteracting boundary accumulation. These findings reveal edge-dependent mechanisms for topological mode formation in non-Hermitian photonic quantum dots and offer potential strategies for device miniaturization and controlling light localization in synthetic gauge-field platforms.