DYNAMICS OF EXCITONS IN QUANTIZED MAGNETIC FIELD IN MULTI-COMPONENT ELECTRON SYSTEMS
Characterization and processing of semiconductor nanostructures and application as...
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Author(s): |
Salviano de Araújo Leão
Total Authors: 1
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Document type: | Doctoral Thesis |
Press: | São Carlos. |
Institution: | Universidade de São Paulo (USP). Instituto de Física de São Carlos (IFSC/BT) |
Defense date: | 1997-01-22 |
Examining board members: |
Marcos Henrique Degani;
Marilia Junqueira Caldas;
Liderio Citrangulo Ioriatti Junior;
Gilmar Eugenio Marques;
Maria Cristina dos Santos
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Advisor: | Marcos Henrique Degani |
Abstract | |
We have studied the electronic properties of two different quasi-one-dimensional systems solving self-consistently the Schrödinger and Poisson equation. The method we use to calculate the electronic levels is based on the solution of the time-dependent Schrödinger equation using the split-operator technique. In the first system we have studied, we present a theoretical calculation of the electronic structure of v-groove quantum wires confined in modulation-doped n-AlxGa1-xAs/GaAs. The system investigated is saw tooth corrugated by bendings with period of 850 ANGSTROM. Results of the electronic structure are obtained as a function of the gate voltage and the donor impurity density. The electronic density shows the existence of a quasi one-dimensional electron gas. The second system studied here is composed by a two-dimensional electron gas confined at the interface of an Al1-xGa1-xAs/GaAs heterostructure, on top of which there is a periodic structure of gates. When a negative voltage is applied to the gates, the regions at the interface beneath them are depleted and quantum wires are formed. We have calculated the electronic structure of subband of that system. We investigated the electronic properties of the quantum wires as a function of gate voltage, from which we determine the threshold between the 2D and ID transitions, the temperature and the ionized donor density. (AU) |