title: One-dimensional polaritons with size-tunable and enhanced coupling strengths in semiconductor nanowires.
abstract: Strong coupling of light with excitons in direct bandgap semiconductors leads to the formation of composite photonic-electronic quasi-particles (polaritons), in which energy oscillates coherently between the photonic and excitonic states with the vacuum Rabi frequency. The light-matter coherence is maintained until the oscillator dephases or the photon escapes. Exciton-polariton formation has enabled the observation of Bose-Einstein condensation in the solid-state, low-threshold polariton lasing and is also useful for terahertz and slow-light applications. However, maintaining coherence for higher carrier concentration and temperature applications still requires increased coupling strengths. Here, we report on size-tunable, exceptionally high exciton-polariton coupling strengths characterized by a vacuum Rabi splitting of up to 200 meV as well as a reduction in group velocity, in surface-passivated, self-assembled semiconductor nanowire cavities. These experiments represent systematic investigations on light-matter coupling in one-dimensional optical nanocavities, demonstrating the ability to engineer light-matter coupling strengths at the nanoscale, even in non-quantum-confined systems, to values much higher than in bulk.
authors.affiliation: Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Lambert K
authors.initials: LK
authors.lastname: van Vugt
authors.forename: Brian
authors.initials: B
authors.lastname: Piccione
authors.forename: Chang-Hee
authors.initials: CH
authors.lastname: Cho
authors.forename: Pavan
authors.initials: P
authors.lastname: Nukala
authors.forename: Ritesh
authors.initials: R
authors.lastname: Agarwal
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry; D004581:Electronics; D008027:Light; D049449:Luminescence; D008422:Materials Testing; D008962:Models, Theoretical; D053770:Nanowires; D010777:Photochemistry; D017785:Photons; D045663:Quantum Dots; D012666:Semiconductors; D013440:Sulfides / Q000737:chemistry; D013499:Surface Properties
chemical_list: D019187:Cadmium Compounds; D013440:Sulfides; C034939:cadmium sulfide