Monolayer transition metal dichalcogenides (TMDCs) have recently been proposed as a unique excitonic platform for advanced optical and electronic functionalities. However, in spite of intense research efforts, it has been largely overlooked that, in addition to displaying rich exciton physics, TMDCs also possess a very high refractive index. This opens a possibility to utilize these materials for constructing resonant nanoantennas based on subwavelength geometrical modes. Here we show that nanodisks fabricated from exfoliated multilayer WS$_2$ support distinct Mie resonances and so-called anapole states that can be easily tuned in wavelength over the visible and near-infrared spectral range by varying the nanodisks' size and aspect ratio. We argue that the TMDC material anisotropy and the presence of excitons substantially enrich nanophotonics by complementing traditional approaches based on plasmonics and well-known high-index materials such as silicon. 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. Our results thus suggest that nanopatterned TMDCs are promising materials for high-index nanophotonics applications with enriched functionalities and superior prospects.
Materials Physics Center, CSIC-UPV/EHU（材料物理中心，西班牙科学研究中心-巴斯克国立大学）；CIC NanoGUNE BRTA and Department of Electricity and Electronics, EHU/UPV（纳米技术循环中心BRTA和电气电子系，巴斯克国立大学）；Department of Physics, Chalmers University of Technology（查尔姆斯理工大学物理系）；Department of Photonics Engineering, Technical University of Denmark（丹麦技术大学光子工程系）；Center for Photonics and 2D Materials, Moscow Institute of Physics and Technology（莫斯科物理科学与技术学院光子和二维材料中心）；IKERBASQUE, Basque Foundation for Science（伊克尔巴斯基，巴斯克科学基金会）；Donostia International Physics Center DIPC（圣塞巴斯蒂安国际物理中心）
Enhanced magneto-optical intensity effect in a helicity-preserving all-dielectric metasurface at Mie resonances and the anapole state
Russian Quantum Center（俄罗斯量子中心）；Moscow Institute of Physics and Technology (MIPT)（莫斯科物理技术学院）；Faculty of Physics, M.V. Lomonosov Moscow State University（莫斯科国立大学物理系）；National Engineering Research Center of Electromagnetic Radiation Control Materials, University of Electronic Science and Technology of China（电子科技大学电磁辐射控制材料国家工程研究中心）；State Key Laboratory of Electronic Thin-Films and Integrated Devices, University of Electronic Science and Technology of China（电子科技大学电子薄膜与集成器件国家重点实验室）
