title: Approaching the strong coupling limit in single plasmonic nanorods interacting with J-aggregates.
abstract: We studied scattering and extinction of individual silver nanorods coupled to the J-aggregate form of the cyanine dye TDBC as a function of plasmon--exciton detuning. The measured single particle spectra exhibited a strongly suppressed scattering and extinction rate at wavelengths corresponding to the J-aggregate absorption band, signaling strong interaction between the localized surface plasmon of the metal core and the exciton of the surrounding molecular shell. In the context of strong coupling theory, the observed "transparency dips" correspond to an average vacuum Rabi splitting of the order of 100 meV, which approaches the plasmon dephasing rate and, thereby, the strong coupling limit for the smallest investigated particles. These findings could pave the way towards ultra-strong light-matter interaction on the nanoscale and active plasmonic devices operating at room temperature.
authors.affiliation: Department of Applied Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden.
authors.forename: Gülis
authors.initials: G
authors.lastname: Zengin
authors.forename: Göran
authors.initials: G
authors.lastname: Johansson
authors.forename: Peter
authors.initials: P
authors.lastname: Johansson
authors.forename: Tomasz J
authors.initials: TJ
authors.lastname: Antosiewicz
authors.forename: Mikael
authors.initials: M
authors.lastname: Käll
authors.forename: Timur
authors.initials: T
authors.lastname: Shegai