Probing Wigner correlations in a suspended carbon nanotube

TL;DR

This paper investigates how electron-vibron coupling affects Wigner correlations in a suspended carbon nanotube quantum dot, revealing that vibrational interactions suppress observable Wigner oscillations, especially under weak Coulomb interactions.

Contribution

It demonstrates that electron-vibron coupling suppresses Wigner correlation signatures, providing insights into probing Wigner molecules in suspended nanotubes.

Findings

Electron-vibron coupling suppresses chemical potential oscillations.

Suppression is more significant under weak Coulomb interactions.

Probing Wigner correlations remains feasible despite vibrational effects.

Abstract

The influence of the electron-vibron coupling on the transport properties of a strongly interacting quantum dot built in a suspended carbon nanotube is analyzed. The latter is probed by a charged AFM tip scanned along the axis of the CNT which induces oscillations of the chemical potential and of the linear conductance. These oscillations are due to the competition between finite-size effects and the formation of a Wigner molecule for strong interactions. Such oscillations are shown to be suppressed by the electron-vibron coupling. The suppression is more pronounced in the regime of weak Coulomb interactions, which ensures that probing Wigner correlations in such a system is in principle possible.