Application of density functional theory for a circular quantum dot

Abstract

To study the ground-state electronic structures of N-electron quantum dots. Calculations based on the spin-density-functional theory have been performed in real space within the local spin-density approximation. The recently proposed analytic representation of the exchange-correlation energy functional of Attaccalite et al was used instead of the most used form of Tanatar and Cepeley. The effect of the confining potential and the electron-electron interaction on the electronic structures were examined. For Harmonic confinement, the addition energy spectra obtained shows a clear shell structure as a function of N corresponding to the unusually large peaks at N = 2, 6, 12, and the smaller peaks at N = 4, and 9. The geometry deformation of a circular quantum dot was studied by varying the geometry parameter of anisotropic parabolic confining potential. The calculated results show that there still exists the shell structure corresponding to N = 2, 6 and 12 for the slightly deformed circular quantum dot. Shell-filling and spin configuration are found to determined mostly by Hund's rule. These findings are in very good agreement with previously observed experimental result.