Coupling of shells in a carbon nanotube quantum dot

TL;DR

This paper investigates how different shells in a carbon nanotube quantum dot interact, using spectroscopy and theoretical modeling to understand the effects of disorder on their coupling.

Contribution

It introduces a comprehensive study combining experimental spectroscopy with a theoretical model to analyze shell coupling induced by disorder in nanotube quantum dots.

Findings

Good agreement between experimental spectra and theoretical calculations.

Disorder-induced coupling significantly affects the excitation spectrum.

Shell interactions depend on magnetic field orientation.

Abstract

We systematically study the coupling of longitudinal modes (shells) in a carbon nanotube quantum dot. Inelastic cotunneling spectroscopy is used to probe the excitation spectrum in parallel, perpendicular and rotating magnetic fields. The data is compared to a theoretical model including coupling between shells, induced by atomically sharp disorder in the nanotube. The calculated excitation spectra show good correspondence with experimental data.