Electron-Phonon Correlation Effects in Molecular Transistors

TL;DR

This paper analyzes how electron-electron and electron-phonon interactions influence molecular transistors, revealing effects like weakened gate dependence, new fluctuation channels, and observable spectral features.

Contribution

It provides an analytical study of electron-phonon effects in the Kondo regime, introducing a model that explains experimental anomalies and predicts spectral signatures.

Findings

Weakening of Kondo temperature dependence on gate voltage

Emergence of a dynamical Jahn-Teller distortion

Low energy peak in phonon spectral density

Abstract

The interplay of electron-electron and electron-phonon interactions is studied analytically in the Kondo regime. A Holstein electron-phonon coupling is shown to produce a weakening of the gate voltage dependence of the Kondo temperature and may explain the observed anomalies in some of these devices. A molecular center-of-mass mode opens a new channel for charge and spin fluctuations and in the antiadabatic limit the latter are described by an asymmetric two-channel Kondo model. Below the Kondo temperature the system develops a dynamical Jahn-Teller distortion and a low energy peak emerges in the phonon spectral density that could be observed in Raman microscopy experiments.