Shallow-Donor States in Spherical Quantum Dots with Parabolic Confinement
Abstract
The evidence of a parabolic potential well in quantum wires and dots was reported in the literature, and a parabolic potential is often considered to be a good representation of the 'barrier' potential in semiconductor quantum dots. In the present work, the variational and fractional-dimensional space approaches are used in a thorough study of the binding energy of on-center shallow donors in spherical GaAs-Ga(1-x)Al(x)As quantum dots with potential barriers taken either as rectangular V(sub b) (eV) = 1.247 x for r > R or parabolic V(sub b) (r) = Beta(sup 2) r(sup 2) isotropic barriers. We define the parabolic potential with a Beta parameter chosen so that it results in the same E0 ground state energy as for the spherical quantum dot of radius R and rectangular potential in the absence of the impurity. Calculations using either the variational or fractional-dimensional approaches both for rectangular and parabolic potential result in essentially the same on-center binding energies provided the dot radius is not too small. This indicates that both potentials are alike representations of the quantum-dot barrier potential for a radius R quantum dot provided the parabolic potential is defined with Beta chosen as mentioned above.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2002
- Accession Number
- ADP012650
Entities
People
- C. A. Duque
- L. E. Oliveira
- M. De Dios-leyva
- N. Porras-montenegro
Organizations
- University of Valle