Surface Plasmon Mediated Strong Exciton−Photon Coupling in Semiconductor Nanocrystals

• Published in: Nano letters 2010-01, Vol.10 (1), p.274-278
• Main Authors: Gómez, D. E, Vernon, K. C, Mulvaney, P, Davis, T. J
• Format: Article
• Language: English
• Subjects: Cadmium Compounds - chemistry; Collective excitations (including excitons, polarons, plasmons and other charge-density excitations); Colloids - chemistry; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Crystallization; Electrochemistry - methods; Electron states; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Excitons and related phenomena; Materials science; Nanocrystalline materials; Nanoparticles - chemistry; Nanoscale materials and structures: fabrication and characterization; Nanostructures - chemistry; Nanotechnology - methods; Photons; Physics; Quantum Dots; Selenium Compounds - chemistry; Semiconductors; Silver - chemistry; Surface and interface electron states; Surface Plasmon Resonance; Temperature
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl903455z

We present an experimental demonstration of strong coupling between a surface plasmon propagating on a planar silver thin film and the lowest excited state of CdSe nanocrystals. Attenuated total reflection measurements demonstrate the formation of plasmon−exciton mixed states, characterized by a Rabi splitting of ∼112 meV at room temperature. Such a coherent interaction has the potential for the development of nonlinear plasmonic devices, and furthermore, this system is akin to those studied in cavity quantum electrodynamics, thus offering the possibility to study the regime of strong light−matter coupling in semiconductor nanocrystals under easily accessible experimental conditions.