Diffusion Monte Carlo study of circular quantum dots

We present ground- and excited-state energies obtained from diffusion Monte Carlo (DMC) calculations, using accurate multiconfiguration wave functions , for N electrons (N less than or equal to 13) confined to a circular quant um dot. We compare the density and correlation energies to the predictions of local spin density approximation (LSDA) theory, and analyze the electron -electron pair-correlation functions. The DMC estimated change in electroch emical potential as a function of the number of electrons in the dot is com pared to that from LSDA and HF calculations. Hund's first rule is found to be satisfied for all dots except N = 4 for which there is a near degeneracy .