ELECTRON INTERACTION IN A QUANTUM-DOT WITH HARD-WALL CONFINEMENT POTENTIAL

We have investigated the electron interaction energy in a circular qua ntum dot with hard confinement potential, using a renormalized perturb ation series (RPS) approach which interpolates between the perturbatio n solutions in the weak interaction regime and the asymptotic solution s in the strong interaction regime. The RPS is based on the scaling pr operty of the Hamiltonian, and the numerical procedure is not complica ted even when the number of electrons in the dot is not very small. Th e accuracy of the RPS calculation has been tested with two electrons i n a dot, where the RPS ground state energy agrees with the exact numer ical solution within 1% relative error. We have performed the RPS calc ulation for three and four electrons in the dot, from which the Coulom b charging energy is derived. The results suggest the potential applic ation of pillar-shaped quantum dots for single-electron tunneling tran sistors operating at higher temperatures.