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Spatially resolved optical spectroscopy on natural quantum dots
- Source :
- Applied Surface Science; January 1998, Vol. 124 Issue: 4 p356-365, 10p
- Publication Year :
- 1998
-
Abstract
- We report about optical experiments on (i) natural quantum dots formed by well width fluctuations in narrow GaAs quantum wells and on (ii) self-assembled InGaAs quantum dots in GaAs. Contributions from a single natural quantum dot are isolated by spatially resolved spectroscopy and resonant charge injection in an electric-field-tunable coupled quantum well structure. In optical experiments the excitonic and bi-excitonic ground states are identified and growth related interface problems are analyzed. Spectral linewidths down to 50 meV allow thereby a complete separation of the individual levels and Zeeman sub-levels of the dot. The natural quantum dots with their fully resolved Zeeman levels are used as local probes to monitor the spin orientation and the creation of spin-polarized excitons in coupled quantum well structures. With cathodoluminescence excited by a scanning tunneling microscope tip and a special sample design we are able to excite selectively the ground state of a single self-assembled InGaAs quantum dot.
Details
- Language :
- English
- ISSN :
- 01694332
- Volume :
- 124
- Issue :
- 4
- Database :
- Supplemental Index
- Journal :
- Applied Surface Science
- Publication Type :
- Periodical
- Accession number :
- ejs2988932
- Full Text :
- https://doi.org/10.1016/S0169-4332(97)00455-8