Selective photoexcitation of exciton-polariton vortices Ga¨ el Nardin, Konstantinos G. Lagoudakis, Barbara Pietka, Fran¸cois Morier-Genoud, Yoan L´ eger, Benoˆıt Deveaud-Pl´edran Laboratoire d’Opto´ electronique Quantique, ´ Ecole Polytechnique F´ ed´ erale de Lausanne (EPFL), Station 3, CH-1015 Lausanne, Switzerland. Abstract We resonantly excite exciton-polariton states confined in cylindrical traps. Using a homodyne detection setup, we are able to image the phase and amplitude of the confined polariton states. We evidence the excitation of vortex states, carrying an integer angular orbital momentum m , analogous to the transverse TEM$_{01}$ ∗ “donut” mode of cylindrically symmetric optical resonators. Tuning the excitation conditions allows us to select the charge of the vortex. In this way, the injection of singly charged ( m = 1 & m = − 1) and doubly charged ( m = 2) polariton vortices is shown. This work demonstrates the potential of in-plane confinement coupled with selective excitation for the topological tailoring of polariton wavefunctions. arXiv:1001.0846v3 [cond-mat.quant-gas] 30 May 2010 1