Two interacting electrons in low-lying states in a spherical quantum dot

The energy spectra of two electrons in low-lying excited states in a spherical quantum dot are estimated with different barrier heights. The screened electron-electron interaction is treated through a dielectric function and the correlation energy is calculated for different dot sizes. The two electron problem is also treated as an effective one body problem. It is found that: (i) correlation effects are significant for smaller dots, (ii) spatial-dependent screening function does not lead to appreciable changes in binding energies, (iii) the effects of barrier height is appreciable on confinement and it has no effect on correlation energy of electrons and (iv) the effect of binding energy for smaller dots is substantial when included the correlation effect more than treated as one body problem.