Theory of the STM detection of Wigner molecules in spin incoherent CNTs

TL;DR

This paper investigates how the linear conductance in a spin-incoherent carbon nanotube quantum dot reveals the presence of Wigner molecules through spatial oscillations and power-law scaling, using a double-tip setup.

Contribution

It introduces a theoretical framework for detecting Wigner molecules in CNTs via conductance measurements in the spin-incoherent regime.

Findings

Conductance shows spatial oscillations due to Wigner molecules.

Power-law scaling relates electron density and conductance to interaction strength.

Double-tip setup enables exploration of different transport regimes.

Abstract

The linear conductance of a carbon nanotube quantum dot in the Wigner molecule regime, coupled to two scanning tunnel microscope tips is inspected. Considering the high temperature regime, the nanotube quantum dot is described by means of the spin-incoherent Luttinger liquid picture. The linear conductance exhibits spatial oscillations induced by the presence of the correlated, molecular electron state. A power-law scaling of the electron density and of the conductance as a function of the interaction parameter are found. They confirm local transport as a sensitive tool to investigate the Wigner molecule. The double-tip setup allows to explore different transport regimes with different shapes of the spatial modulation, all bringing information about the Wigner molecule.