Engineering the spatial confinement of exciton-polaritons in   semiconductors
  We demonstrate the spatial confinement of electronic excitations in a solid state system, within novel artificial structures that can be designed having arbitrary dimensionality and shape. The excitations under study are exciton-polaritons in a planar semiconductor microcavity. They are confined within a micron-sized region through lateral trapping of their photon component. Striking signatures of confined states of lower and upper polaritons are found in angle-resolved light emission spectra, where a discrete energy spectrum and broad angular patterns are present. A theoretical model supports unambiguously our observations. 
Reda Idrissi Kaitouni, Ounsi El Daif, Maxime Richard, Pierre Lugan,   Augustin Baas, Thierry Guillet, Fran\c{c}ois Morier-Ge...