2011/01/31 by A. Amo, S. Pigeon, D. Sanvitto +9 · 4 citations
Physics and Astronomy · #cond-mat.quant-gas #cond-mat.mes-hall
paper · pdf · doi:10.1126/science.1202307
published as Science 332, 1167-1170 (2011) · Published version with corrected colorbar scale for Fig. 3. Raw data available as ancillary files
arxiv created 2015/12/02 · arxiv updated 2015/12/03
A quantum fluid passing an obstacle behaves differently from a classical one. When the flow is slow enough, the quantum gas enters a superfluid regime and neither whirlpools nor waves form around the obstacle. For higher flow velocities, it has been predicted that the perturbation induced by the defect gives rise to the turbulent emission of quantised vortices and to the nucleation of solitons. Using an interacting Bose gas of exciton-polaritons in a semiconductor microcavity, we report the transition from superfluidity to the hydrodynamic formation of oblique dark solitons and vortex streets in the wake of a potential barrier. The direct observation of these topological excitations provides key information on the mechanisms of superflow and shows the potential of polariton condensates for quantum turbulence studies.