Abstract
We present nanosecond time-resolved measurements of the low-temperature photoluminescence in coupled GaAs/As quantum wells. Working with 10.0-nm and 15.0-nm GaAs quantum wells coupled through a 3.0-nm As barrier layer, we observe spatially indirect excitons with lifetimes in excess of 200 nsec—an enhancement of more than 2 orders of magnitude over the lifetime of the spatially direct exciton. As a result, extremely cold GaAs exciton gases become possible, a prerequisite for testing recent predictions of quantum-statistical behavior in this system.
- Received 21 December 1989
DOI:https://doi.org/10.1103/PhysRevB.41.8564
©1990 American Physical Society