Backscattering suppression in supersonic 1D polariton condensates
  We investigate the effects of disorder on the propagation of one-dimensional polariton condensates in semiconductor microcavities. We observe a strong suppression of the backscattering produced by the imperfections of the structure when increasing the condensate density. This suppression occurs in the supersonic regime and is simultaneous to the onset of parametric instabilities which enable the "hopping" of the condensate through the disorder. Our results evidence a new mechanism for the frictionless flow of polaritons at high speeds. 
Dimitrii Tanese, Dmitry Solnyshkov, Alberto Amo, Lydie Ferrier,   Emmanuel Bernet-Rolland, Esther Wertz, Isabelle Sagnes, Ar...
cond-mat.quant-gas cond-mat.other