Near infrared anapole-exciton polaritons in metallic-dielectric hybrid nanostructures.

Enhancing light-matter interactions at the nanoscale holds remarkable promise for advancing a broad range of research areas, spanning physics, materials science, and nanophotonics. Nevertheless, achieving robust optical mode coupling in practical systems remains challenging due to limited field confinement and inefficient access of active materials to electromagnetic hotspots. In this theoretical study, we demonstrate the feasibility of strong coupling between the anapole mode of a slotted silicon nanodisk and excitons in single-walled carbon nanotubes (SWCNTs) at near-infrared frequencies. By introducing the anapole mode, we effectively confine electromagnetic fields to subwavelength volumes with suppressed radiative losses, enabling an electric field enhancement of up to 1200-fold. This remarkable enhancement, combined with the favorable spatial overlap between the anapole hotspot and the SWCNT layer, gives rise to a Rabi splitting of 78 meV. Moreover, we show that the coupling strength can be further reinforced by tuning the SWCNT thickness and oscillator strength, with Rabi splittings reaching as high as 122 meV and 198 meV, respectively. Our findings not only deepen the fundamental understanding of anapole-exciton strong coupling at the nanoscale but also establish a versatile platform for designing high-performance polaritonic devices based on dielectric-SWCNT hybrid architectures.