A triple quantum dot in a single wall carbon nanotube

TL;DR

This paper demonstrates the creation and control of three coupled quantum dots within a single wall carbon nanotube, analyzing their electronic behavior through experiments and simulations.

Contribution

It introduces a method to define and control three quantum dots in a single nanotube and models their interactions with a capacitor and tunnel coupling.

Findings

Successful fabrication of triple quantum dots in a nanotube

Good agreement between experimental data and capacitor model simulations

Observation of anti-crossings and higher order cotunneling phenomena

Abstract

A top-gated single wall carbon nanotube is used to define three coupled quantum dots in series between two electrodes. The additional electron number on each quantum dot is controlled by top-gate voltages allowing for current measurements of single, double and triple quantum dot stability diagrams. Simulations using a capacitor model including tunnel coupling between neighboring dots captures the observed behavior with good agreement. Furthermore, anti-crossings between indirectly coupled levels and higher order cotunneling are discussed.