Steady state oscillations of circular currents in concentric polariton condensates

Concentric ring exciton polariton condensates emerging under non-resonant laser pump in an annular trapping potential support persistent circular currents of polaritons. The trapping potential is formed by a cylindrical micropillar etched in a semiconductor microcavity with embedded quantum wells and a repulsive cloud of optically excited excitons under the pump spot. The symmetry of the potential is subject to external control via manipulation by its pump-induced component. In the manuscript, we demonstrate excitation of concentric ring polariton current states with predetermined vorticity which we trace using interferometry measurements with a spherical reference wave. We also observe the polariton condensate dynamically changing its vorticity during observation, which results in pairs of fork-like dislocations on the time-averaged interferogram coexisting with azimuthally homogeneous photoluminescence distribution in the micropillar.

Automated summary

By using a cylindrical micropillar with embedded quantum wells in a semiconductor microcavity, a trapping potential is formed which supports concentric ring exciton polariton condensates under a non-resonant laser pump. The external control of the potential's symmetry is achieved through manipulation by its pump-induced component. In this study, we demonstrate the excitation of concentric ring polariton current states with predetermined vorticity and observe the dynamic change of the polariton condensate's vorticity during observation, resulting in fork-like dislocations on the time-averaged interferogram coexisting with azimuthally homogeneous photoluminescence distribution in the micropillar.