Creation of orbital angular momentum states with chiral polaritonic   lenses
  Controlled transfer of orbital angular momentum to exciton-polariton Bose-Einstein condensate spontaneously created under incoherent, off-resonant excitation conditions is a long-standing challenge in the field of microcavity polaritonics. We demonstrate, experimentally and theoretically, a simple and efficient approach to generation of nontrivial orbital angular momentum states by using optically-induced potentials -- chiral polaritonic lenses. 
Robert Dall, Michael D. Fraser, Anton S. Desyatnikov, Guangyao Li,   Sebastian Brodbeck, Martin Kamp, Christian Schneider, S...
cond-mat.quant-gas