Correlation energy in a spherical quantum dot

The binding energies of two electrons in a spherical quantum dot with square-well potential confinement are considered. The electron-electron interaction is included through a screened coulomb potential using the Richardson-Vinsome screening function applicable to GaAs. The finite barrier model leads to the following conclusions: (i) the correlation energy is more significant for dots of smaller radii and larger barrier heights; and (ii) the effect of the position-dependent screening function is not significant. Our results are in good agreement with Szafran et al., [Physica E 5 (2000) 185.] who used an infinite barrier with parabolic confinement. The correlation contributes 30-40% to the binding energy. (C) 2007 Elsevier B.V. All rights reserved.