Effect of interlevel Coulomb interactions on the tunneling current through a single quantum dot

The tunneling current through a quantum dot (QD) embedded in SiO2 matrix is studied theoretically. The energy levels and Coulomb interactions of electrons in a nanometer QD are calculated using an effective mass model. The tunneling current of a QD is calculated using the Keldysh-Green function method and two-level Anderson model. In addition to four peaks arising from the intralevel Coulomb interactions, extra differential conductance peaks are found due to the interlevel Coulomb interactions and the statistical nature of the open system.