Transition metal dichalcogenide nanodisks as high-index dielectric Mie nanoresonators

Artikel i vetenskaplig tidskrift, 2019

Monolayer transition metal dichalcogenides (TMDCs) have recently been proposed as an excitonic platform for advanced optical and electronic functionalities 1–3 . However, in spite of intense research efforts, it has not been widely appreciated that TMDCs also possess a high refractive index 4,5 . This characteristic opens up the possibility to utilize them to construct resonant nanoantennas based on subwavelength geometrical modes 6,7 . Here, we show that nanodisks, fabricated from exfoliated multilayer WS 2 , support distinct Mie resonances and anapole states 8 that can be tuned in wavelength over the visible and near-infrared range by varying the nanodisk size and aspect ratio. As a proof of concept, we demonstrate a novel regime of light–matter interaction—anapole-exciton polaritons—which we realize within a single WS 2 nanodisk. We argue that the TMDC material anisotropy and the presence of excitons enrich traditional nanophotonics approaches based on conventional high-index materials and/or plasmonics.