Manipulation of unidirectional side scattering of light in transition metal dichalcogenide nanoresonators

All-dielectric optical nanoantennas from high-refractive-index materials are becoming a promising way for efficient manipulation of light at the nanoscale. Here we propose an all-dielectric nanostructure based on bulk transition metal dichalcogenides (TMDs) with very simple geometry, a single-element nanodisk with an off-centered hole sited on glass substrate. We demonstrate that such TMD-based nanostructures can be utilized as a high-performance controllable directional nanoantenna due to its aspect of high refractive index in visible range. Owing to the off-centered hole, scattering spectrum of the nanodisk presents an extra Mie resonance, which is dominated by electric and magnetic dipole of Mie resonance. The interference between them leads to a transverse Kerker effect with an efficient unidirectional sides scattering around the Mie resonance. Importantly, we further investigate the intrinsic coupling between the TMD excitons and Mie resonance, as well as the influence of the coupling on the unidirectional side scattering of the system. We show that unidirectional side scattering occurs for both newly formed polariton states as a direct consequence of self-hybridized exciton-Mie interaction. Their directivities are strongly dependent on the directional feature of the Mie resonance, which can be effectively controlled by size of the nanodisk and the position of off-centered hole. Our results may provide exciting possibility for efficient light manipulations and are expected to open new pathways for the design of novel nanophotonic devices.