First-principles study of electron transport in few-electron open quantum dots by the Hartree–Fock approach

Electron transport properties of few-electron open quantum dots within the spin-restricted Hartree–Fock approximation are studied. The self-consistent numerical calculations were performed for a whole device, including the semi-infinite leads, without employing any phenomenological or adjustable parameters. Inclusion of the non-local Fock potential brings qualitatively new physics in comparison to the Hartree approach: electron screening decreases, resonant energy levels become less pinned to the Fermi energy and clearly correlate with conductance peaks. When coupling between the dot and leads decreases the number of electrons inside the dot becomes quantized and the model predicts the Coulomb blockade of electron transport. This is confirmed by comparison with the master equation approach for an equivalent quantum dot.

► External confinement potential of a quantum dot.
► Occupancy, conductance and energy structure of the dot calculated in the Hartree, Hartree–Fock, and master equation approaches.
► Representative charge densities in the dot calculated in the Hartree and Hartree–Fock approaches for similar dot's occupancy.