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Quantum Electronics and Laser Science Conference

Dephasing of the LH-HH exciton Raman coherence in GaAs quantum wells: distinguishing between phonon and carrier scattering

Amelia G. VanEngen Spivey, Cecilia Borca, Steven T. Cundiff

Published Dec 10, 2005• 0 citations
Publisher

Abstract

Three-beam four-wave mixing shows anti-correlated scattering of HH and LH excitons in GaAs/AlGaAs quantum wells, suggesting that exciton-phonon scattering dominates the exciton dephasing. The correlation increases at higher excitation densities.
DOI
10.1109/qels.2005.1549327

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Quantum beats involving the light hole (lh) and heavy hole (hh) excitons in GaAs are observed using homodyne detection of the transient four-wave mixing response. Unlike the beats of earlier studies, these beats are detected in a geometry for which the effect would be forbidden in the absence of exciton interactions and arise from coherence induced between the lh and hh excitons. The beats demonstrate the existence of the Raman coherence due to interaction, and the decay of the coherence shows the correlation of exciton dephasing rates to be relatively unaffected by the interaction.
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