Electric field induced tuning of electronic correlation in weakly confining quantum dots

TL;DR

This study combines experiments and theory to explore how electric fields influence electronic correlations and properties in weakly confining GaAs quantum dots, revealing effects on dipole moments, binding energies, and hole mixing.

Contribution

It provides a detailed analysis of the quantum-confined Stark effect in weakly confining quantum dots, emphasizing the importance of electronic correlation effects and improving understanding beyond common models.

Findings

Excellent agreement between experiment and configuration-interaction calculations

Electric field significantly alters dipole moments and binding energies

Electronic correlations critically influence Stark shifts in weakly confining dots

Abstract

We conduct a combined experimental and theoretical study of the quantum-confined Stark effect in GaAs/AlGaAs quantum dots obtained with the local droplet etching method. In the experiment, we probe the permanent electric dipole and polarizability of neutral and positively charged excitons weakly confined in GaAs quantum dots by measuring their light emission under the influence of a variable electric field applied along the growth direction. Calculations based on the configuration-interaction method show excellent quantitative agreement with the experiment and allow us to elucidate the role of Coulomb interactions among the confined particles and -- even more importantly -- of electronic correlation effects on the Stark shifts. Moreover, we show how the electric field alters properties such as built-in dipole, binding energy, and heavy-light hole mixing of multiparticle complexes in weakly confining systems, underlining the deficiencies of commonly used models for the quantum-confined Stark effect.