Van der Waals Nanoantennas on Gold as Hosts for Hybrid Mie-Plasmonic Resonances

Abstract

Dielectric nanoresonators have been shown to circumvent the heavy optical losses associated with plasmonic devices, however they suffer from less confined resonances. By constructing a hybrid system of both dielectric and metallic materials, one can retain the low losses of dielectric resonances, whilst gaining additional control over the tuning of the modes with the metal, and achieving stronger mode confinement. In particular, multi-layered van der Waals materials are emerging as promising candidates for integration with metals owing to their weak attractive forces, which enable deposition onto such substrates without the requirement of lattice matching. Here we use layered, high refractive index WS${}_2$ exfoliated on gold, to fabricate and optically characterize a hybrid nanoantenna-on-gold system. We experimentally observe a hybridization of Mie resonances, Fabry-Pérot modes, and surface plasmon-polaritons launched from the nanoantennas into the substrate. We achieve experimental quality factors of Mie-plasmonic modes of up to 20 times that of Mie resonances in nanoantennas on silica, and observe signatures of a supercavity mode with a Q factor of 263 $\pm$ 28, resulting from strong mode coupling between a higher-order anapole and Fabry-Pérot-plasmonic mode. We further simulate WS${}_2$ nanoantennas on gold with an hBN spacer, resulting in calculated electric field enhancements exceeding 2600, and a Purcell factor of 713. Our results demonstrate dramatic changes in the optical response of dielectric nanophotonic structures placed on gold, opening new possibilities for nanophotonics and sensing with simple-to-fabricate devices.

21 + 11 pages, 5 + 7 figures

References in corpus (17)

• Two Dimensional Atomic Crystals
• Ultrafast Charge Transfer in Atomically Thin MoS2/WS2 Heterostructures
• Hunting for Monolayer Boron Nitride: Optical and Raman Signatures
• High-Q supercavity modes in subwavelength dielectric resonators
• Ultrafast transition between exciton phases in van der Waals heterostructures
• Enhanced Light-Matter Interaction in Two-Dimensional Transition Metal Dichalcogenides
• Single photon emitters in hexagonal boron nitride: A review of progress
• Hybrid Exciton-Plasmon-Polaritons in van der Waals Semiconductor Gratings
• MENP: An Open-Source MATLAB Implementation of Multipole Expansion for Applications in Nanophotonics
• Lasing action in single subwavelength particles supporting supercavity modes
• Bright single photon emitters with enhanced quantum efficiency in a two-dimensional semiconductor coupled with dielectric nano-antennas
• Van der Waals Materials for Applications in Nanophotonics
• Interlayer excitons in van der Waals heterostructures: Binding energy, Stark shift, and field-induced dissociation
• Super-Resolution Nanolithography of Two-Dimensional Materials by Anisotropic Etching
• Nonlinear interactions of dipolar excitons and polaritons in MoS2 bilayers
• Transition metal dichalcogenide dimer nano-antennas with ultra-small gaps
• Hybrid Dielectric-Plasmonic Nanoantenna with Multiresonances for Subwavelength Photon Sources