Transport properties of quantum dots in the Wigner molecule regime

TL;DR

This paper investigates how electron interactions in quantum dots lead to Wigner molecule formation, significantly affecting their transport properties, with observable signatures in conductance behavior across different regimes.

Contribution

It introduces a projected Hartree-Fock approach to study transport in quantum dots, revealing how Wigner molecules influence conductance in linear and nonlinear regimes.

Findings

Wigner molecules form as interactions increase, affecting transport signatures.

Conductance is exponentially suppressed with stronger interactions.

Nonlinear regimes can show conductance enhancement due to molecular states.

Abstract

The transport properties of quantum dots with up to N=7 electrons ranging from the weak to the strong interacting regime are investigated via the projected Hartree-Fock technique. As interactions increase radial order develops in the dot, with the formation of ring and centered-ring structures. Subsequently, angular correlations appear, signalling the formation of a Wigner molecule state. We show striking signatures of the emergence of Wigner molecules, detected in transport. In the linear regime, conductance is exponentially suppressed as the interaction strength grows. A further suppression is observed when centered-ring structures develop, or peculiar spin textures appear. In the nonlinear regime, the formation of molecular states may even lead to a conductance enhancement.