Correlation Effects in Quantum Dot Wave Function Imaging

TL;DR

This paper shows that wave function imaging of semiconductor quantum dots reveals electron-electron Coulomb correlation effects, especially in low-density regimes where standard mean-field methods fail, and can indicate Wigner crystallization.

Contribution

It predicts that quasi-particle wave functions in quantum dots exhibit correlation signatures and cannot be accurately modeled by mean-field techniques in strongly correlated regimes.

Findings

Wave function images show Coulomb correlation signatures.

Quasi-particle wave functions indicate Wigner crystallization.

Standard mean-field methods are inadequate for strongly correlated quantum dots.

Abstract

We demonstrate that in semiconductor quantum dots wave functions probed by imaging techniques based on local tunneling spectroscopies like STM show characteristic signatures of electron-electron Coulomb correlation. We predict that such images correspond to ``quasi-particle'' wave functions which cannot be computed by standard mean-field techniques (density functional theory, Hartree-Fock) in the strongly correlated regime corresponding to low electron density. From the configuration-interaction solution of the few-particle problem for prototype dots, we find that quasi-particle wave function images may display signatures of Wigner crystallization.