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Donor impurity related optical and electronic properties of cylindrical GaAs-Al(x)Ga(1−x) As quantum dots under tilted electric and magnetic fields

This article makes a theoretical study of the optical and electronic properties in cylindrical GaAs-Al(x) Ga(1−x) As quantum dots in the presence of an arbitrarily located donor impurity and considering the simultaneous effects of tilted electric and magnetic fields. The studies are developed in the...

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Autores principales: Heyn, Christian, Duque, C. A.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7280517/
https://www.ncbi.nlm.nih.gov/pubmed/32513977
http://dx.doi.org/10.1038/s41598-020-65862-9
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author Heyn, Christian
Duque, C. A.
author_facet Heyn, Christian
Duque, C. A.
author_sort Heyn, Christian
collection PubMed
description This article makes a theoretical study of the optical and electronic properties in cylindrical GaAs-Al(x) Ga(1−x) As quantum dots in the presence of an arbitrarily located donor impurity and considering the simultaneous effects of tilted electric and magnetic fields. The studies are developed in the effective mass and parabolic band approximations. The solution of the Schrödinger equation is done through the finite element method considering tetrahedral meshes that can be adapted to regions where there are abrupt variations of the materials that make up the structure. Among the many results, reported for the first time in this article, we can mention: (i) the electronic spectrum, without and with shallow donor impurity, considering separate and combined effects of tilted electric and magnetic fields, (ii) the ground state binding energy as a function of the external electric and magnetic fields, their orientations concerning the axial axis of the quantum dot, and the impurity position, (iii) the squared reduced dipole matrix elements for impurity related inter-level optical transitions as a function of the tilted electric and magnetic fields and impurity position, and (iv) the optical absorption coefficient between the ground state and at least the first fifteen lowest excited states under tilted electric and magnetic fields and considering several impurity positions. From this study it can be concluded that the presence of tilted electric and magnetic fields and on-center or off-center shallow donor impurities, ostensibly enrich the optical and electronic properties of the system. It is observed that due to the rupture of the azimuthal symmetry of the cylindrical quantum dot, important modifications of the selection rules for inter-level transitions between states appear.
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spelling pubmed-72805172020-06-15 Donor impurity related optical and electronic properties of cylindrical GaAs-Al(x)Ga(1−x) As quantum dots under tilted electric and magnetic fields Heyn, Christian Duque, C. A. Sci Rep Article This article makes a theoretical study of the optical and electronic properties in cylindrical GaAs-Al(x) Ga(1−x) As quantum dots in the presence of an arbitrarily located donor impurity and considering the simultaneous effects of tilted electric and magnetic fields. The studies are developed in the effective mass and parabolic band approximations. The solution of the Schrödinger equation is done through the finite element method considering tetrahedral meshes that can be adapted to regions where there are abrupt variations of the materials that make up the structure. Among the many results, reported for the first time in this article, we can mention: (i) the electronic spectrum, without and with shallow donor impurity, considering separate and combined effects of tilted electric and magnetic fields, (ii) the ground state binding energy as a function of the external electric and magnetic fields, their orientations concerning the axial axis of the quantum dot, and the impurity position, (iii) the squared reduced dipole matrix elements for impurity related inter-level optical transitions as a function of the tilted electric and magnetic fields and impurity position, and (iv) the optical absorption coefficient between the ground state and at least the first fifteen lowest excited states under tilted electric and magnetic fields and considering several impurity positions. From this study it can be concluded that the presence of tilted electric and magnetic fields and on-center or off-center shallow donor impurities, ostensibly enrich the optical and electronic properties of the system. It is observed that due to the rupture of the azimuthal symmetry of the cylindrical quantum dot, important modifications of the selection rules for inter-level transitions between states appear. Nature Publishing Group UK 2020-06-08 /pmc/articles/PMC7280517/ /pubmed/32513977 http://dx.doi.org/10.1038/s41598-020-65862-9 Text en © The Author(s) 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Heyn, Christian
Duque, C. A.
Donor impurity related optical and electronic properties of cylindrical GaAs-Al(x)Ga(1−x) As quantum dots under tilted electric and magnetic fields
title Donor impurity related optical and electronic properties of cylindrical GaAs-Al(x)Ga(1−x) As quantum dots under tilted electric and magnetic fields
title_full Donor impurity related optical and electronic properties of cylindrical GaAs-Al(x)Ga(1−x) As quantum dots under tilted electric and magnetic fields
title_fullStr Donor impurity related optical and electronic properties of cylindrical GaAs-Al(x)Ga(1−x) As quantum dots under tilted electric and magnetic fields
title_full_unstemmed Donor impurity related optical and electronic properties of cylindrical GaAs-Al(x)Ga(1−x) As quantum dots under tilted electric and magnetic fields
title_short Donor impurity related optical and electronic properties of cylindrical GaAs-Al(x)Ga(1−x) As quantum dots under tilted electric and magnetic fields
title_sort donor impurity related optical and electronic properties of cylindrical gaas-al(x)ga(1−x) as quantum dots under tilted electric and magnetic fields
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7280517/
https://www.ncbi.nlm.nih.gov/pubmed/32513977
http://dx.doi.org/10.1038/s41598-020-65862-9
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