Charge pumping in carbon nanotube quantum dots

TL;DR

This paper explores how surface acoustic waves can induce charge pumping in carbon nanotube quantum dots, revealing current reversal phenomena and modeling charge redistribution.

Contribution

It introduces a model explaining charge pumping in nanotubes driven by acoustic waves, highlighting the role of adiabatic charge redistribution.

Findings

Current reverses polarity at small amplitudes near Coulomb peaks

Charge pumping depends on wave amplitude, frequency, and direction

Develops a theoretical model for adiabatic charge redistribution

Abstract

We investigate charge pumping in carbon nanotube quantum dots driven by the electric field of a surface acoustic wave. We find that at small driving amplitudes, the pumped current reverses polarity as the conductance is tuned through a Coulomb blockade peak using a gate electrode. We study the behavior as a function of wave amplitude, frequency and direction and develop a model in which our results can be understood as resulting from adiabatic charge redistribution between the leads and quantum dots on the nanotube.