Optical orientation of bright excitons in InAs/GaAs quantum dots: Influence of a Faraday magnetic field and the dark exciton states
| Autor: | M. Chaouache, Aristide Lemaître, B. Eble, M.A. Maaref, Frédéric Bernardot, S. Sancho, Christophe Testelin |
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| Přispěvatelé: | Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de photonique et de nanostructures (LPN), Centre National de la Recherche Scientifique (CNRS), French-Tunisian Project [09-G-1307], Comite Mixte pour la Cooperation Universitaire |
| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
Physics
Photoluminescence Condensed matter physics Condensed Matter::Other Exciton 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics Polarization (waves) Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 01 natural sciences Electronic Optical and Magnetic Materials Magnetic field Condensed Matter::Materials Science Quantum dot Excited state 0103 physical sciences [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] 010306 general physics 0210 nano-technology Biexciton Excitation |
| Zdroj: | Physical Review B: Condensed Matter and Materials Physics (1998-2015) Physical Review B: Condensed Matter and Materials Physics (1998-2015), American Physical Society, 2011, 84 (15), ⟨10.1103/PhysRevB.84.155458⟩ Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2011, 84 (15), ⟨10.1103/PhysRevB.84.155458⟩ |
| ISSN: | 1098-0121 1550-235X |
| DOI: | 10.1103/PhysRevB.84.155458⟩ |
| Popis: | International audience; We study the injection of polarized bright and dark excitons in quantum dots, under nonresonant or resonant excitation, by polarization-resolved photoluminescence experiments on an ensemble of self-assembled InAs/GaAs quantum dots. The importance of the polarized dark exciton creation on the optical emission under magnetic field is discussed. Under circular excitation, we observe the expected increase and saturation of the polarization rate with a magnetic field applied in Faraday geometry. Strikingly, the polarization rate slightly decreases for magnetic fields greater than similar to 1.5 T; the feature is more pronounced for higher interband energies and is attributed to a more efficient initial polarization of the dark exciton states. This interpretation is confirmed by the lack of decrease of the polarization rate for quantum dots excited at exact resonance through a 1LO-phonon-assisted transition. Finally, we measure the bright exciton exchange energy as a function of interband emission energy, we measure a decrease from 65 to 30 mu eV in the range 1.28-1.35 eV, and we obtain an estimate of the dark exciton splitting. |
| Databáze: | OpenAIRE |
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