Fine structure of bright and dark excitons in asymmetric droplet epitaxy GaAs/AlGaAs quantum dots
| Autor: | A. Pankratov, Christophe Testelin, Maria Chamarro, S. Ben Radhia, K. Boujdaria, H. Mekni |
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| Přispěvatelé: | Laboratoire de Physique des Matériaux, Faculté des Sciences de Bizerte, Université de Carthage, 7021 Zarzouna, Tunisie and Laboratoire de Physique de la Matière Condensée, Faculté des Sciences de Tunis, Université de Tunis El Manar, 2092 El Manar, Tunisie, Photonique et cohérence de spin (INSP-E12), Institut des Nanosciences de Paris (INSP), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Annealing (metallurgy) Exciton media_common.quotation_subject Exchange interaction Astrophysics::Cosmology and Extragalactic Astrophysics 02 engineering and technology Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology Epitaxy 01 natural sciences Asymmetry Molecular physics Condensed Matter::Materials Science [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph] Quantum dot 0103 physical sciences [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] Perturbation theory 010306 general physics 0210 nano-technology Anisotropy media_common |
| Zdroj: | Physical Review B Physical Review B, American Physical Society, 2021, 103 (7), ⟨10.1103/PhysRevB.103.075302⟩ |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.103.075302 |
| Popis: | International audience; We have calculated the exciton fine structure splittings (FSS) of asymmetric GaAs/AlGaAs quantum dots (QDs) obtained after Al droplet epitaxy and subsequent nanoholes formation followed by annealing and GaAs filling of nanoholes. We used a k • p model and considered the heavy-hole and light-hole mixing to calculate the electron-hole exchange interaction (EI). The two components, long-range (LR) and short-range (SR) of the EI, were deduced. The exciton fine structure is organized, as usual in zinc-blende compounds, into two groups of states: bright (optically active) and dark states. The bright-dark and bright-bright splittings contain LR and SR contributions, the LR part representing 5 to 68% of the total bright-dark splitting and 69 to 76% of the total bright-bright splitting for sizes experimentally explored. In QDs having C 2v symmetry, LR and SR contributions to dark-dark splitting have to be calculated at the second order of perturbation theory. A good agreement between the theory and experiment is obtained for QDs with different degrees of asymmetry, from QD having an isotropic shape to QD with a very anisotropic shape. |
| Databáze: | OpenAIRE |
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