Photon-Phonon-assisted tunneling through a single-molecular quantum dot

TL;DR

This paper investigates photon-phonon-assisted tunneling in a single-molecular quantum dot under microwave irradiation, revealing additional peaks in conductance due to photon absorption/emission and phonon interactions using Green function techniques.

Contribution

It introduces an exact mapping approach combined with nonequilibrium Green functions to analyze time-dependent phonon-assisted tunneling in quantum dots under microwave fields.

Findings

Additional peaks in conductance due to photon processes

Photon absorption influences phonon emission

Current varies with microwave frequency

Abstract

Based on exactly mapping of a many-body electron-phonon interaction problem onto a one-body problem, we apply the well-established nonequilibrium Green function technique to solve the time-dependent phonon-assisted tunneling at low temperature through a single-molecular quantum dot connected to two leads, which is subject to a microwave irradiation field. It is found that in the presence of the electron-phonon interaction and the microwave irradiation field, the time-average transmission and the nonlinear differential conductance display additional peaks due to pure photon absorption or emission processes and photon-absorption-assisted phonon emission processes. The variation of the time-average current with frequency of the microwave irradiation field is also studied.