Noise-assisted Thouless pump in elastically deformable molecular junctions

TL;DR

This paper investigates how noise and non-linear dynamics in an elastically deformable quantum dot influence quantum charge pumping, revealing that noise can enhance the pump's efficiency near vibrational resonance and analyzing temperature effects.

Contribution

It introduces a model of a noise-affected quantum pump with non-linear vibrational dynamics, showing noise can strengthen pumping near resonance, which is a novel insight.

Findings

Quantum pumping is enhanced near vibrational resonance.

Noise does not destroy but can strengthen the pump.

Pumped charge decays exponentially with temperature.

Abstract

We study a Thouless pump realized with an elastically \textit{deformable quantum dot} whose center of mass follows a non-linear stochastic dynamics. The interplay of noise, non-linear effects, dissipation and interaction with an external time-dependent driving on the pumped charge is fully analyzed. The results show that the quantum pumping mechanism not only is not destroyed by the force fluctuations, but it becomes stronger when the forcing signal frequency is tuned close to the resonance of the vibrational mode. The robustness of the quantum pump with temperature is also investigated and an exponential decay of the pumped charge is found when the coupling to the vibrational mode is present. Implications of our results for nano-electromechanical systems are also discussed.