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Enhanced resonant backscattering of excitons in disordered quantum wells
W Langbein1, E Runge, V Savona
1Experimentelle Physik IIb, Universität Dortmund, Otto-Hahn-Strasse 4, Germany.
Physical Review Letters
|October 9, 2002
Summary
Enhanced backscattering of excitons was observed in disordered quantum wells. This phenomenon, linked to exciton localization length, differs from other backscattering physics.
Area of Science:
- Condensed Matter Physics
- Quantum Optics
- Materials Science
Background:
- Disordered quantum wells host localized excitons.
- Exciton dynamics and light scattering are crucial for understanding quantum systems.
- Backscattering phenomena are observed in various physical systems.
Purpose of the Study:
- To investigate enhanced backscattering of excitons in disordered quantum wells.
- To analyze the spectral dependence and time dynamics of this scattering.
- To explore the relationship between exciton localization and backscattering.
Main Methods:
- Directional resonant Rayleigh scattering measurements.
- Spectral dependence and time dynamics analysis.
- Theoretical prediction and quantitative modeling.
Main Results:
- Observed clear signature of enhanced exciton backscattering.
- Measured spectral and temporal dynamics quantitatively.
- Found intensity enhancement extending beyond the emission cone.
- Linked enhancement to small exciton localization length near the band bottom.
Conclusions:
- Enhanced exciton backscattering is a distinct phenomenon in disordered quantum wells.
- Exciton localization length, controllable by photon energy, dictates backscattering.
- This behavior offers a qualitative difference compared to other backscattering phenomena.
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