Theory of Current and Shot Noise Spectroscopy in Single-Molecular Quantum Dots with Phonon Mode

TL;DR

This paper investigates how electron-phonon interactions affect current and shot noise in a single-molecular quantum dot, revealing satellite peaks and split noise peaks, with proposed experimental verification.

Contribution

It introduces a theoretical analysis of shot noise and conductance in molecular quantum dots with phonon coupling using nonequilibrium Green functions.

Findings

Satellite peaks in conductance due to phonon modes

Split peaks in shot noise in resonant tunneling

Single peaks in phonon-assisted tunneling

Abstract

Using the Keldysh nonequilibrium Green function technique, we study the current and shot noise spectroscopy of a single molecular quantum dot coupled to a local phonon mode. It is found that in the presence of electron-phonon coupling, in addition to the resonant peak associated with the single level of the dot, satellite peaks with the separation set by the frequency of phonon mode appear in the differential conductance. In the ``single level'' resonant tunneling region, the differential shot noise power exhibit two split peaks. However, only single peaks show up in the ``phonon assisted'' resonant-tunneling region. An experimental setup to test these predictions is also proposed.