Self-consistent electronic structure, coulomb interaction, and spin effects in self-assembled strained InAs-GaAs quantum dot structures

We have performed a detailed self-consistent calculation of the electronic structure and charging effects in a pyramidal self-assembled InAs-GaAs quantum dot. Within the effective mass approximation, our model is general for three-dimensional quantum devices, without simplifying assumptions on the shape of the confining potential nor fitting parameters. We have used a continuum model for the strain, from which a position dependent effective mass is calculated. The number of electrons in the dot is controlled by applying external voltage to a metal gate on the top of a complete multilayer device. Ln order to determine the electron occupation number in the dot which minimizes the total energy of the system, we have adopted the concept of transition state for shell filling in atoms. We have calculated the exchange term of the many-body Hamiltonian using the local spin density approximation (LSDA). Comparison with the experimental data shows good agreement. (C) 1998 Elsevier Science B.V. All rights reserved.