Internal Transitions of Negatively Charged Magnetoexcitons and Many Body Effects in a Two-Dimensional Electron Gas
| Autor: | B. D. McCombe, A. Yu. Sivachenko, Vladimir Umansky, Alexander B. Dzyubenko, William J. Schaff, H. A. Nickel, T. Yeo, Athos Petrou |
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| Rok vydání: | 2002 |
| Předmět: |
Physics
Electron density Condensed Matter (cond-mat) FOS: Physical sciences General Physics and Astronomy Resonance Condensed Matter 02 engineering and technology Electron Type (model theory) Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology 01 natural sciences Many body Spectral line 0103 physical sciences Atomic physics 010306 general physics 0210 nano-technology Quantum well Excitation |
| Zdroj: | Physical Review Letters. 88 |
| ISSN: | 1079-7114 0031-9007 |
| Popis: | Spin-singlet and spin-triplet internal transitions of quasi-two-dimensional, negatively charged magneto-excitons (X-) and their evolution with excess electron density have been studied in GaAs/AlGaAs quantum-wells by optically detected resonance (ODR) spectroscopy. In the dilute electron limit, due to magnetic translational invariance, the ODR spectra are dominated by bound-to-continuum bands in contrast to the superficially similar negatively-charged-donor system D-, which exhibits strictly bound-to-bound transitions. With increasing excess electron density in the wells in the magnetic field region corresponding to Landau level filling factors nu < 2 the X- like transitions are blue-shifted; they are absent for nu > 2. The blue-shifted transitions are explained in terms of a new type of collective excitation -- magnetoplasmons bound to a mobile valence band hole, which demonstrates the many-body nature of "exciton-like" magnetoluminescence for nu < 2. 11 pages + 3 figures, final version accepted in PRL |
| Databáze: | OpenAIRE |
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