Piston-assisted charge pumping

TL;DR

This paper explores a charge pumping mechanism driven by a oscillating piston in a three-site system, demonstrating how charge can be transferred against a voltage gradient, with implications for biological and semiconductor systems.

Contribution

It introduces a novel charge pumping mechanism involving a modulated middle site, explaining biological proton pumping and potential applications in nanostructures.

Findings

Charge can be transferred against an applied voltage.

The mechanism explains proton pumping in mitochondrial enzyme Complex I.

Potential application in electron pumping in semiconductor nanostructures.

Abstract

We examine charge transport through a system of three sites connected in series in the situation when an oscillating charged piston modulates the energy of the middle site. We show that with an appropriate set of parameters, charge can be transferred against an applied voltage. In this scenario, when the oscillating piston shifts away from the middle site, the energy of the site decreases and it is populated by a charge transferred from the lower energy site. On the other hand, when the piston returns to close proximity, the energy of the middle site increases and it is depopulated by the higher energy site. Thus through this process, the charge is pumped against the potential gradient. Our results can explain the process of proton pumping in one of the mitochondrial enzymes, Complex I. Moreover, this mechanism can be used for electron pumping in semiconductor nanostructures.