Coherent Flow and Trapping of Polariton Condensates with Long Lifetime
  We report new results of Bose-Einstein condensation of polaritons in specially designed microcavities with very high quality factor, on the order of $10^6$, giving the polariton lifetimes of the order of 100 ps. When the polaritons are created with an incoherent pump, a dissipationless, coherent flow of the polaritons occurs over hundreds of microns, which increases as density increases. At high density, this flow is suddenly stopped, and the gas becomes trapped in a local potential minimum, with strong coherence. 
Bryan Nelsen, Gangqiang Liu, Mark Steger, David W. Snoke, Ryan Balili,   Ken West and Loren Pfeiffer
cond-mat.quant-gas