Collective Mie Exciton-Polaritons in an Atomically Thin Semiconductor

• Main Authors: Wang, Shaojun, Raziman, T. V, Murai, Shunsuke, Castellanos, Gabriel W, Bai, Ping, Berghuis, Anton Matthijs, Godiksen, Rasmus H, Curto, Alberto G, Rivas, Jaime Gómez
• Format: Journal Article
• Language: English
• Published: 30-07-2020
• Subjects: Physics - Optics
• DOI: 10.48550/arxiv.2007.15313

Optically induced Mie resonances in dielectric nanoantennas feature low
dissipative losses and large resonant enhancement of both electric and magnetic
fields. They offer an alternative platform to plasmonic resonances to study
light-matter interactions from the weak to the strong coupling regimes. Here,
we experimentally demonstrate the strong coupling of bright excitons in
monolayer WS$_2$ with Mie surface lattice resonances (Mie-SLRs). We resolve
both electric and magnetic Mie-SLRs of a Si nanoparticle array in angular
dispersion measurements. At the zero detuning condition, the dispersion of
electric Mie-SLRs (e-SLRs) exhibits a clear anti-crossing and a Rabi-splitting
of 32 meV between the upper and lower polariton bands. The magnetic Mie-SLRs
(m-SLRs) nearly cross the energy band of excitons. These results suggest that
the field of m-SLRs is dominated by out-of-plane components that do not
efficiently couple with the in-plane excitonic dipoles of the monolayer WS$_2$.
In contrast, e-SLRs in dielectric nanoparticle arrays with relatively high
quality factors (Q $\sim$ 120) facilitate the formation of collective Mie
exciton-polaritons, and may allow the development of novel polaritonic devices
which can tailor the optoelectronic properties of atomically thin
two-dimensional semiconductors.