Abstract
Four-wave-mixing signals from excitons in high-quality GaAs quantum wells show an unusually slow temporal evolution, in stark contrast to the behavior expected for a noninteracting two-level system. We show that Coulomb interaction effects, generally neglected in the analyses of four-wave-mixing experiments, dominate the signals by 2 orders of magnitude. Numerical calculations based on extended optical Bloch equations for semiconductors provide good qualitative agreement with the data.
- Received 30 April 1992
DOI:https://doi.org/10.1103/PhysRevLett.69.2725
©1992 American Physical Society