Quantum dots based on parabolic quantum wells: importance of electronic correlations

TL;DR

This study investigates the magnetic field-dependent excitation spectra of a two-electron quantum dot based on a parabolic quantum well, highlighting the significance of electronic correlations and their role in Wigner molecule formation.

Contribution

It combines experimental tunneling spectroscopy with theoretical models to analyze electronic correlations in parabolic quantum well quantum dots, emphasizing the importance of correlation effects.

Findings

Good agreement between experiments and theoretical calculations

Electronic correlations are crucial for understanding the system

Formation of an H2-type Wigner molecule is significant

Abstract

We present measurements and theoretical interpretation of the magnetic field dependent excitation spectra of a two-electron quantum dot. The quantum dot is based on an Al$_x$Ga$_{1-x}$As parabolic quantum well with effective $g^\star$-factor close to zero. Results of tunneling spectroscopy of the four lowest states are compared to exact diagonalization calculations and a generalized Heitler--London approximation and good agreement is found. Electronic correlations, associated with the formation of an H$_2$-type Wigner molecule, turn out to be very important in this system.