- 13.09.2011 -
NNL cutting-edge article on Nature Photonics by Daniele Sanvitto
All-optical control of the quantum flow of a polariton condensate Although photons in vacuum are massless particles that do not appreciably interact with each other, significant interactions appear in suitable nonlinear media, leading to hydrodynamic behaviours typical of quantum fluids. Here, we show the generation and manipulation of vortex–antivortex pairs in a coherent gas of strongly dressed photons (polaritons) flowing against an artificial potential barrier created and controlled by a light beam in a semiconductor microcavity. The optical control of the polariton flow allows us to reveal new quantum hydrodynamical phenomenologies such as the formation of vortex pairs upstream from the optical barrier, a case of ultrashort time excitation of the quantum flow, and the generation of vortices with counterflow trajectories.