Optical seminar | 28 January 2022

Exciton polaritons are composite quasiparticles which arise under the strong resonant interaction between the light and semiconductor medium. The interest in studying polaritons is connected with their ability to form the macroscopically coherent many-body state – the condensate which demonstrates superfluid properties. One of the most peculiar manifestations of superfluidity is formation of the persistent currents. Currently, experimental techniques allow for a routine observation of the persistent currents of exciton-polaritons in a closed circular geometry. These currents can be excited spontaneously and maintain their coherent properties during macroscopically long time. This talk reports a recent progress in manipulation and utilization of the circular polariton currents. In particular, we introduce an approach for the realisation of a coherent control over the circular currents of exciton polaritons which is based on the use of an artificial gauge field acting on polaritons. The azimuthal gauge field allows distinguishing between the counter-rotating polariton currents, which can demonstrate manifestations of the equilibrium two-level dynamics though being realized in the intrinsically driven-dissipative setting. Finally, the interaction between two circular currents flowing in a concentric geometry is investigated.