Dynamic Control of Quantum Emitters Strongly Coupled to the Isolated Plasmon Cavity by the Microfluidic Device

Abstract

Strong coupling between quantum emitters and highly localized plasmon fields has attracted enormous attention in quantum science due to the formation of bosonic quasiparticles with light− matter hybrid characteristics. A prerequisite for correlative applications is the on-demand, in situ manipulation of the coupling process. Here, a dynamic control from weak coupling to strong coupling between the condensed plasmon field in ultracompact nanoantenna and tunable excitons in J-aggregates is proposed. Using the microfluidic technique, we achieve a flexible tuning of the coupled J-aggregate exciton number N from 0 to ∼3 in an isolated single Au@Ag nanocavity by continuously varying the dye concentration adjacent to the plasmon hotspots in the nanoscale space. The emergence and evolution of hybrid plexcitons are clearly presented in the single-particle dark-field scattering spectra with a Rabi splitting of up to 167 meV. Numerical calculations quantify the relation of coupling strength to injected dye concentration. Our work proposes a novel way to achieve highly controllable and ultracompact plasmon−exciton strong coupling systems, paving the way for advanced quantum plasmonic applications and ultrasensitive biochemical nanosensors.

Strong Coupling of Ag@Au Hollow Nanocube/J-Aggregate Heterostructures by Absorption Spectra

“…Traditionally, the strong coupling (SC) of optical microcavities and excitons has been studied extensively, but it also involves considerable experimental difficulties, such as cryogenic temperatures, ultrahigh vacuum, and production problems. , These problems can be solved well using plasmonic nanocavity systems because they can break through the diffraction limit to localize the light at the nanometer scale. So plasmonic nanocavity can not only enhance the emission of the excitons but also easily achieve SC at room temperature. , Therefore, in recent years, studies on the SC of plasmonic nanocavities and excitons have made big progresses. − …”

Trends of Biosensing: Plasmonics through Miniaturization and Quantum Sensing

“…As a result, the analysis of the signal evidences that the intensity grows because of the waveguide/molecule coupling (panel ii) more than for a condition of the molecule off guide. It is important to note that in these complex systems, which did not possess a quantum intrinsic nature, the interaction between light and matter was stimulated and amplified by nonlinear effects and interactions of photons with the surrounding matter as well as by instantaneous electric field enhancement imposed on the photons by brief pulses [132,142] . Alternative techniques for single-photon emission have been demonstrated, based on the coupling of optical fields with quantum emitters like a defect in a solid, atom, ion, or quantum dots.…”