Strong coupling as an interplay of quantum emitter hybridization with plasmonic dark and bright modes
Journal article, 2020

Strong coupling between a single quantum emitter and an electromagnetic mode is one of the key effects in quantum optics. In the cavity QED approach to plasmonics, strongly coupled systems are usually understood as single-transition emitters resonantly coupled to a single radiative plasmonic mode. However, plasmonic cavities also support nonradiative (or "dark") modes, which offer much higher coupling strengths. On the other hand, realistic quantum emitters often support multiple electronic transitions of various symmetries, which could overlap with higher order plasmonic transitions-in the blue or ultraviolet part of the spectrum. Here, we show that despite very large detuning between a bright mode and an excitonic transition, their strong coupling can be ensured by leveraging higher energy dark modes of the optical cavity. Specifically, when a dark mode interacts strongly with an excitonic transition, the lower polariton of the hybridized spectrum can be pushed to energies of the bright mode. The resulting interaction of the lower dark-mode-exciton polariton and bright mode yields significant vacuum Rabi splitting, which hinges on the existence of the dark mode. We develop a simple model illustrating the modification of the system response in the "dark" strong coupling regime and demonstrate single photon nonlinearity. These results may find important implications in the emerging field of room-temperature quantum plasmonics.

Author

Benjamin Rousseaux

Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics

Denis Baranov

Chalmers, Physics, Nano and Biophysics

Tomasz Antosiewicz

Chalmers, Physics, Bionanophotonics

Timur Shegai

Chalmers, Physics, Nano and Biophysics

Göran Johansson

Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics

PHYSICAL REVIEW RESEARCH

2643-1564 (eISSN)

Vol. 2 3 033056

Subject Categories

Atom and Molecular Physics and Optics

Other Physics Topics

Condensed Matter Physics

DOI

10.1103/PhysRevResearch.2.033056

More information

Latest update

1/28/2021