Suppressed Quenching and Strong Coupling of Purcell-Enhanced Single-Molecule Emission in Plasmonic Nanocavities

TL;DR

This study reveals that plasmonic nanocavities can suppress quenching and enable strong coupling with single molecules, leading to enhanced radiative emission and observable Rabi oscillations, challenging previous assumptions about emitter decay near metal nanostructures.

Contribution

It demonstrates that plasmonic nanocavities can overcome quenching effects through mode hybridization, enabling strong coupling with single molecules, which was previously thought unfeasible.

Findings

Suppressed quenching in plasmonic nanocavities due to mode hybridization.

Observation of Rabi oscillations indicating strong coupling.

Experimental confirmation via DNA-origami positioning.

Abstract

An emitter in the vicinity of a metal nanostructure is quenched by its decay through non-radiative channels, leading to the belief in a zone of inactivity for emitters placed within $<$10nm of a plasmonic nanostructure. Here we demonstrate that in tightly-coupled plasmonic resonators forming nanocavities "quenching is quenched" due to plasmon mixing. Unlike isolated nanoparticles, plasmonic nanocavities show mode hybridization which massively enhances emitter excitation and decay via radiative channels. This creates ideal conditions for realizing single-molecule strong-coupling with plasmons, evident in dynamic Rabi-oscillations and experimentally confirmed by laterally dependent emitter placement through DNA-origami.