Observation of nonequilibrium motion and equilibration in polariton rings

Abstract

Recent progress in fabricating long-lifetime semiconductor microcavities has improved the thermalization of polaritons, quasiparticles arising from the strong coupling between photons and excitons in a microcavity. Here, the authors image nondestructively the real-time dynamics of the excited polaritons settling to the bottom of a tilted ring trap, which shows damped pendulum-like oscillations akin to atomic condensates in optical harmonic traps. Smoking gun evidence for extremely long transport lengths of the exciton reservoir is shown, which opens a new perspective for reservoir engineering.