Abstract
We use terahertz pulses to induce resonant transitions between the eigenstates of optically generated exciton populations in a high-quality semiconductor quantum well sample. Monitoring the excitonic photoluminescence, we observe transient quenching of the exciton emission, which we attribute to the terahertz-induced -to- excitation. Simultaneously, a pronounced enhancement of the exciton emission is observed, despite the -to- transition being dipole forbidden. A microscopic many-body theory explains the experimental observations as a Coulomb-scattering mixing of the and states, yielding an effective terahertz transition between the and populations.
- Received 18 March 2012
DOI:https://doi.org/10.1103/PhysRevLett.110.137404
© 2013 American Physical Society