Exciton-Polariton Flows in Cross-Dimensional Junctions
  We study the nonequilibrium exciton-polariton condensation in 1D to 0D and 1D to 2D junctions by means of non-resonant spectroscopy. The shape of our potential landscape allows to probe the resonant transmission of a propagating condensate between a quasi-1D waveguide and cylindrically symmetric states. We observe a distinct mode selection by varying the position of the non-resonant pump laser. Moreover, we study the the case of propagation from a localized trapped condensate state into a waveguide channel. Here, the choice of the position of the injection laser allows us to tune the output in the waveguide. Our measurements are supported by an accurate Ginzburg-Landau modeling of the system shining light on the underlying mechanisms. 
K. Winkler, H. Flayac, S. Klembt, A. Schade, D. Nevinskiy, M. Kamp, C.   Schneider, S. H\"ofling
cond-mat.mes-hall