From the artificial atom to the Kondo-Anderson model: orientation dependent magneto-photoluminescence of charged excitons in InAs quantum dots

TL;DR

This study investigates the magneto-photoluminescence properties of charged excitons in InAs quantum dots, revealing orientation-dependent electronic behaviors and transitions from Kondo-Anderson to artificial atom models.

Contribution

It provides detailed measurements of Landé tensors and electron wave functions, and demonstrates the evolution of excitonic models with magnetic field orientation in quantum dots.

Findings

Electron wave functions extend into GaAs barriers.

The p-electron g-factor varies with hole presence.

Magneto-photoluminescence shows anticrossings due to state coupling.

Abstract

We present a magneto-photoluminescence study on neutral and charged excitons confined to InAs/GaAs quantum dots. Our investigation relies on a confocal microscope that allows arbitrary tuning of the angle between the applied magnetic field and the sample growth axis. First, from experiments on neutral excitons and trions, we extract the in-plane and on-axis components of the Land\'e tensor for electrons and holes in the s-shell. Then, based on the doubly negatively charged exciton magneto-photoluminescence we show that the p-electron wave function spreads significantly into the GaAs barriers. We also demonstrate that the p-electron g-factor depends on the presence of a hole in the s-shell. The magnetic field dependence of triply negatively charged excitons photoluminescence exhibits several anticrossings, as a result of coupling between the quantum dot electronic states and the wetting layer. Finally, we discuss how the system evolves from a Kondo-Anderson exciton description to the artificial atom model when the orientation of the magnetic field goes from Faraday to Voigt geometry.