Flexible modulation of topological resonator based on different domain walls based on graphene plasmonic valley photonic crystals

Topological edge states (ES) emerge at the interfaces between photonic crystals with distinct topological properties, enabling the suppression of backscattering for unidirectional transmission and exhibiting robustness against defects and disorders. In this work, we propose a flexible modulation strategy for the ES within resonators based on graphene plasmonic valley photonic crystals (VPhCs). Specifically, we initially construct four types of rhombic resonators composed by domain walls using topological valley edge states (VES), achieving localized ES optical fields at various domain walls. Subsequently, four categories of domain walls are heterogeneously integrated to form a single hexagonal resonator. The electromagnetic field distribution in the resonators is dynamically modulated by the variation of the frequency. Our results might provide opportunities for the flexible modulation of ES in graphene plasmonic VPhC resonators, offering prospects for applications in topological plasmonic lasers and high-density micro-nano photonic integration.