2008/12/15 by A. Amo, J. Lefrere, J. Lefrère +13
Engineering · Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Strong Light-Matter Interactions #Thermal Radiation and Cooling Technologies #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1038/nphys1364
published as Nature Phys. 5, 805 (2009) · 14 pages, 3 figures
arxiv created 2008/12/15 · openalex publication_date 2009/09/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
One of the most striking manifestations of quantum coherence in interacting boson systems is superfluidity. Exciton-polaritons in semiconductor microcavities are two-dimensional composite bosons predicted to behave as particular quantum fluids. We report the observation of superfluid motion of polaritons created by a laser in a semiconductor microcavity. Superfluidity is investigated in terms of the Landau criterion and manifests itself as the suppression of scattering from defects when the flow velocity is slower than the speed of sound in the fluid. On the other hand, a Cerenkov-like wake pattern is clearly observed when the flow velocity exceeds the speed of sound. The experimental findings are in excellent quantitative agreement with the predictions based on a generalized Gross-Pitaevskii theory, showing that polaritons in microcavities constitute a very rich system for exploring the physics of non-equilibrium quantum fluids.