Interacting electrons in a 2D quantum dot

The exact numerical diagonalization of the Hamiltonian of a 2D circular qua ntum dot is performed for 2, 3, and 4 electrons. The results an compared wi th those of the perturbation theory. Our numerical results agree reasonably well for small values of the dimensionless coupling constant lambda = a/a( B) where a is the dot radius and a(B) is the effective Bohr radius. Exact d iagonalization results are compared with the classical predictions, and the y are found to be almost coincident for large lambda values. (C) 1999 Elsev ier Science B.V. All rights reserved.