Numéro
Le Journal de Physique IV
Volume 03, Numéro C5, Octobre 1993
Third International Conference on Optics of Excitons in Confined
Page(s) C5-207 - C5-214
DOI http://dx.doi.org/10.1051/jp4:1993540
Third International Conference on Optics of Excitons in Confined

Le Journal de Physique IV 03 (1993) C5-207-C5-214

DOI: 10.1051/jp4:1993540

Quantum beats and polarization interference from excitons in quantum wells

J. FELDMANN

Department of Physics and Materials Sciences Center, Philipps-University of Marburg, Renthof 5, 35032 Marburg, Germany


Abstract
We show that time-resolved quantum beat spectroscopy in the four-wave mixing (FWM) geometry is a unique tool to investigate the electronic multi-level system associated with spectrally adjacent excitonic resonances. We have studied heavy- and light-hole excitons, excitons associated with different and spatially separated quantum wells, and excitons associated with spatially separated growth islands within the same quantum well. Though the linear spectra are qualitatively similar in all three cases, the respective beating of the time-resolved FWM-signal shows a very different dynamic behaviour in each case. We discuss appropriate electronic multi-level schemes and show that exciton transitions within different quantum wells can be described by independent twolevel systems. In contrast, excitonic transitions associated with different and spatially separated growth islands having different quantum well thickness are not independent but coupled.



© EDP Sciences 1993