Realization of light controllable non-Abelian topological state in a plasmonic lattice

The topological properties of multiband systems have recently garnered significant attention due to their potential non-Abelian characteristics, which are absent in single-band or band-gap systems. However, the complex electronic structures inherent in these systems pose challenges for the direct observation of non-Abelian topological phenomena in condensed matter. In this study, we propose a plasmonic system constructed by arranging metal nanoparticles into a T-graphene lattice. This configuration facilitates the realization of non-Abelian topological phase transitions within the resulting photonic multiwave bands, effectively simulating a multiband electronic system. Furthermore, the topological plasmonic states exhibit a diverse array of phases that can be easily controlled by varying the polarization of the external light field, allowing for straightforward observation through measurements of the light field distribution. The results obtained using the eigenequation method are validated through an independent approach, specifically by analytically solving for the electric field distribution; both methods yield consistent findings. This platform, which synergizes the advantages of non-Abelian topological theory with a controllable plasmonic system, holds promise for advancing the field of topological physics and enhancing its applications in plasmonics in the future.