Abstract

A system of indirect (interwell) excitons in coupled quantum wells (CQWs) provides a unique opportunity for experimental study of two-dimensional light composite bosons ther-malized down to ultralow temperatures. The long recombination lifetime of indirect excitons promotes the exciton accumulation in the low energy exciton states and allows the system to cool down to temperatures where the exciton gas becomes degenerate at densities well below the Mott density. We present experimental probe of the theoretically predicted specific bosonic properties of excitons such as stimulated exciton scattering due to high occupancy of exciton state and exciton Bose-Einstein condensation in GaAs/ AlGaAs and AlAs/GaAs GQWs at ultralow temperatures 7_bath > 50 mK.

© 2000 Optical Society of America