Inelastic transport through a single molecular dot in the presence of electron-electron interaction

Abstract

We studied the low-temperature inelastic transport properties of a single quantum dot with the on-site Coulomb repulsive interaction, the electron-phonon interaction, and the electron-photon interaction, using the nonequilibrium Green function (NEGF) approach and the canonical transformation. The time-averaged occupation number, the time-averaged differential conductance and time-averaged current are calculated self-consistently in the quantum dot. The variation in the differential conductance with the frequency of the external field and the incident electron energy is presented. Some interesting electrical transport characteristics come out in the system due to the electron-electron correlation. It is found that the two kinds of phonon-emission peaks may coexist in the time-averaged differential conductance spectrum due to the charge accumulations. One enhances both the time-averaged occupation number and the current even in the low-temperature case, while the other suppresses them. The magnitudes of the phonon peaks are dominated by the time-averaged occupation numbers, so the phonon peaks can be modulated by the external irradiations.