Phonon-assisted transport through a single quantum dot with impurity scattering effects

In this paper, we calculate the current and shot noise for electrons transporting through a single quantum dot with phonon and impurity scatterings. By iteratively calculating the surface Green function, we obtain the self-energy due to coupling between the quantum dot and the semi-infinite leads. Significant couplings to the localized phonon modes and impurity states are included in our model exactly. Our results show that the resonance transmission coefficient and differential conductance split into small peaks in the presence of dot-impurity interaction. Satellite peaks caused by phonon emission (absorption) appear in our results too. As the numerical results, impurity states have weak influence on the suppression of shot noise. On the other hand, shot noise in the conductor will be enhanced if the phonon mode effects are included in our calculations.