Eur. Phys. J. B 27, 385-392 (2002)
https://doi.org/10.1140/epjb/e2002-00169-x

Investigation of excitation energies and Hund's rule in open shell quantum dots by diffusion Monte Carlo

¹ Lawrence Livermore National Laboratory, Livermore, CA 94551-0808, USA
² Dipartimento di Fisica and INFM, Università di Trento, via Sommarive 14, 38050 Povo, Trento, Italy
³ Cornell Theory Center, Cornell University, Ithaca, NY 14853, USA

Corresponding author: ^a pederiva@science.unitn.it

Received: 20 November 2001
Revised: 20 February 2002
Published online: 6 June 2002

Abstract

We use diffusion Monte Carlo to study the ground state, the low-lying excitation spectrum and the spin densities of circular quantum dots with parabolic radial potentials containing N=16 and N=24 electrons, each having four open-shell electrons and compare the results to those obtained from Hartree-Fock (HF) and density functional local spin density approximation (LSDA) calculations. We find that Hund's first rule is obeyed in both cases and that neither HF nor LSDA correctly predict the ordering of the energy levels.