Spectral function of few electrons in quantum wires and carbon nanotubes as a signature of Wigner localization

TL;DR

This paper shows that the spatial spectral function at finite temperature can reveal Wigner localization in electrons within quantum wires and carbon nanotubes, using exact diagonalization of few-particle Hamiltonians.

Contribution

It introduces a method to identify Wigner localization signatures through spectral function profiles at accessible low temperatures.

Findings

Spectral function profiles indicate Wigner localization signatures.

Minimal temperature to suppress exchange effects is in the sub-Kelvin range.

Numerical evidence based on exact diagonalization of few-particle systems.

Abstract

We demonstrate that the profile of the space-resolved spectral function at finite temperature provides a signature of Wigner localization for electrons in quantum wires and semiconducting carbon nanotubes. Our numerical evidence is based on the exact diagonalization of the microscopic Hamiltonian of few particles interacting in gate-defined quantum dots. The minimal temperature required to suppress residual exchange effects in the spectral function image of (nanotubes) quantum wires lies in the (sub-) Kelvin range.