Exciton spectrum of surface-corrugated quantum wells: the adiabatic self-consistent approach
A theory for calculating the relaxation frequency v and the shift δω of exciton resonances in quantum wells with finite potential barriers and adiabatic surface disorder is developed. The adiabaticity implies that the correlation length Rc for the well width fluctuations is much la...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2005 |
| País: | México |
| Institución: | Benemérita Universidad Autónoma de Puebla |
| Repositorio: | Redalyc-BUAP |
| OAI Identifier: | oai:redalyc.org:57063709 |
| Acceso en línea: | https://www.redalyc.org/articulo.oa?id=57063709 |
| Access Level: | acceso abierto |
| Palabra clave: | Física, Astronomía y Matemáticas Excitons quantum wells |
| Sumario: | A theory for calculating the relaxation frequency v and the shift δω of exciton resonances in quantum wells with finite potential barriers and adiabatic surface disorder is developed. The adiabaticity implies that the correlation length Rc for the well width fluctuations is much largerthan the exciton radius a0 (Rc » a0). Our theory is based on the self-consistent Green´s function method, and therefore takes into accountthe inherent action of the exciton scattering on itself. The self-consistent approach is shown to describe quantitatively the sharp exciton resonance. It also gives the qualitatively correct resonance picture for the transition to the classical limit, as well as within the domain of the classical limit itself. We present and analyze results for hh-exciton in a GaAs quantum well with Al0.3Ga0:7As barriers. It is establishedthat the self-consistency and finite height of potential barriers significantly influence on the line-shape of exciton resonances, and make the values of v and δω be quite realistic. In particular, the relaxation frequency v for the ground-state resonance has a broad, almost symmetric maximum near the resonance frequency ωo, while the surface-induced resonance shift δω vanishes near ωo, and has different signs on thesides of the exciton resonance. |
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