Electronic excitation spectrum of metallic carbon nanotubes

TL;DR

This paper investigates the electronic excitation spectrum of metallic carbon nanotubes, revealing a regular four-fold pattern in quantum dots that aligns with theoretical models, enabling full identification of electron states.

Contribution

It provides the first detailed experimental verification of theoretical predictions for the electronic spectra of metallic nanotube quantum dots.

Findings

Observation of a four-fold pattern in stability diagrams

Excellent agreement between measured spectra and theoretical models

Complete identification of electron quantum states in nanotube quantum dots

Abstract

We have studied the discrete electronic spectrum of closed metallic nanotube quantum dots. At low temperatures, the stability diagrams show a very regular four-fold pattern that allows for the determination of the electron addition and excitation energies. The measured nanotube spectra are in excellent agreement with theoretical predictions based on the nanotube band structure. Our results permit the complete identification of the electron quantum states in nanotube quantum dots.