Size-Dependent Coupling of Hybrid Core–Shell Nanorods: Toward Single-Emitter Strong-Coupling

Abstract

Owing to their ability of concentrating electromagnetic fields to subwavelength mode volumes, plasmonic nanoparticles foster extremely high light–matter coupling strengths reaching far into the strong-coupling regime of light–matter interaction. In this article, we present an experimental investigation on the dependence of coupling strength on the geometrical size of the nanoparticle. The coupling strength for differently sized hybrid plasmon–core exciton–shell nanorods was extracted from the typical resonance anticrossing of these systems, obtained by controlled modification of the environment permittivity using layer-by-layer deposition of polyelectrolytes. The observed size dependence of the coupling strength can be explained by a simple model approximating the electromagnetic mode volume by the geometrical volume of the particle. On the basis of this model, the coupling strength for particles of arbitrary size can be predicted, including the particle size necessary to support single-emitter strong coupling.

Strong light–matter interactions: a new direction within chemistry

“…In addition to organic molecules and inorganic structures in the solid state, some more exotic materials have shown hybridization with light. For example, different kinds of polymers,23,87,130–135 molecules in liquid phases,85,112,136–138 organic liquid crystals,57,139,140 organic crystals,44,141,142 quantum dots,42,143–145 nanocrystals in various geometries,124–126,146–156 nano-wires,157–161 nanographene,162 proteins,163–165 light-harvesting complexes,166 and photosynthetic bacteria have been hybridized with light 167,168. In the following sections, a review of accomplishments within the strong coupling regime is made.…”

Optical Spectra of Plasmon--Exciton Core--Shell Nanoparticles: A Heuristic Quantum Approach

“…We further tested the model by investigating particles with different sizes and therefore with different coupling energies ℏΩ 0 . 39 In the purely classical approach, we expect the additional peak to be more pronounced for smaller particles as the relative amount of excitonic material rises. These effects are also observed for the simple model of a Drude sphere with a Lorentz shell (see Supplementary Information).…”

Efficient DNA-Driven Nanocavities for Approaching Quasi-Deterministic Strong Coupling to a Few Fluorophores

“…However, recent reports suggest that the splitting in the scattering spectrum is insufficient for claiming the strong coupling between emitters and nanocavities [30][31][32][33] . In order to further confirm the coupling between the Cy5 exciton and the gap dipole mode of the particle-on-film nanocavity, photoluminescence (PL) spectrum [31][32][34][35][36][37] and photobleaching tests are both utilized 38 .…”