Speaker
Description
We have created a spatially homogeneous polariton condensate in thermal equilibrium. In-situ, non-destructive measurement of the coherence allows us to extract the quasicondensate fraction. These measurements reveal a striking 7/2 power law for the quasicondensate fraction overly nearly three orders of magnitude of density. The same power law is seen in simulations solving the generic two-dimensional Gross-Pitaevskii equation for the equilibrium coherence, showing that it is a universal result. This power law has not been predicted by prior analytical theories; prior measurements of coherence with cold atoms did not have sufficient accuracy to observe it.
In a separate set of experiments, we have shown persistent circulation of a polariton condensate in a ring trap, which is initiated by a short (1-2 picosecond) stirring pulse and then persists without degradation and without any addition stirring for as long as we can measure (14 nanoseconds) in a stable steady state.
