Transport properties of a molecular quantum dot coupled to one-dimensional correlated electrons

TL;DR

This paper investigates how a molecular quantum dot coupled to one-dimensional correlated electrons affects transport properties, revealing divergences at resonance and finite corrections off-resonance, with implications for experimental measurements.

Contribution

It provides explicit expressions for the full counting statistics and analyzes divergence corrections using diagram resummation in a correlated electron system.

Findings

Negative, divergent current correction near phonon frequency at resonance

Finite correction to current off-resonance due to non-monotonic transmission

Calculated noise power corrections and discussed experimental implications

Abstract

We analyze the transport properties of a quantum dot with a harmonic degree of freedom (Holstein phonon) coupled to interacting one-dimensional metallic leads. Using Tomonaga-Luttinger model to describe the interacting leads we construct the generating function of the full counting statistics (FCS) for a specific constellation of system parameters and give explicit expression for the cumulant generating function. In the resonant case we find the lowest order correction to the current to be negative and divergent when source-drain voltage approaches the phonon frequency. Via a diagram resummation procedure we show, that this divergencies can be repealed. On the contrary, in the off-resonant case the lowest order correction remains finite. This effect can be traced back to the strongly non-monotonic behaviour of the bare transmission coefficient (without phonon) with respect to the dot level energy. We calculate corrections to the noise power as well and discuss possible experimental implications of this phenomenon.