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Quantum beats from extended electronic states in quantum wells

Quantenoszillationen ausgedehnter elektrischer Zustände in Quantum Wells

Anastassakis, E.M.; Joannopoulos, J.D.:
20th International Conference on the Physics of Semiconductors 1990
Singapore: World Scientific, 1990
ISBN: 981-02-0539-2
pp.1481-1484 : Abb.,Lit.
International Conference on the Physics of Semiconductors <20, 1990, Thessaloniki>
Conference Paper
Fraunhofer IAF ()
III-V Halbleiter; III-V semiconductors; time resolved PL; tunneling; tunneln; zeitaufgelöste Photolumineszenz

We study the polarization decay of excitons in GaAs/AlGaAs quantum wells using timeresolved degenerate-four-wave-mixing (DFWM) with subpicosecond time resolution. The coherent excitation of two energetically close exciton transitions enables the observation of quantum beats in the diffracted signal. We observe such quantum beats between (I) light-hole and heavy-hole excitons, (II) heavy-hole excitons split by spatially varying confinement, and (III) anticrossed levels in a coupled quantum well structure. We furthermore show that the DFWM lineshape reveals a novel polarization interaction.