Exact Diagonal Calculations of Coulomb Oscillations in Quantum Dots

Abstract

Transport properties through a quantum dot are examined based on exact diagonal calculations of many-body states, when the Coulomb interaction energy is comparable with one-electron level spacings. The peak positions of Coulomb oscillation show an atomic-like shell structure of one-electron levels, in agreement with recent experimental results. Some peaks of the conductance increase in height with increasing temperature. This anomalous temperature dependence reflects a level spacing as small as 1K and total spin of the ground state. The transport properties through coupled two dots are also investigated. We show that the correlation effect influences the peak heights of the conductance. These phenomena exemplify the observation of many-body wavefunctions in quantum dots, by the Coulomb oscillation.