Vortices in Polariton Superfluids.

The experimental investigation of spontaneously created vortices is of utmost importance for the understanding of quantum phase transitions towards a superfluid phase, especially for two-dimensional systems that are expected to be governed by the Berezinski-Kosterlitz-Thouless physics. By means of time-resolved near-field interferometry the team of Prof. Benoît Deveaud-Plédran (LOEQ - Laboratory of Quantum Optoelectronics) track the path of such vortices, created at random locations in an exciton-polariton condensate under pulsed nonresonant excitation, to their final pinning positions imposed by the stationary disorder. They formulate a theoretical model that successfully reproduces the experimental observations.

K. G. Lagoudakis et al., Phys. Rev. Lett. 106, 115301, doi: 10.1103/PhysRevLett.106.115301 (2011)