Dissipationless Flow and Sharp Threshold of a Polariton Condensate with Long Lifetime

Exciton polaritons are essentially photons ``dressed'' by and interacting via their interaction with excitons in a semiconductor. As bosons, they exhibit Bose-Einstein condensation, in which they self-organize into a coherent state. Scientists have now extended their lifetime from 10 to 100 picoseconds and have observed a number of dramatic new effects, including a new and dynamic coherent state of spatially localized polaritons at high densities.