Impact of heavy hole-light hole coupling on optical selection rules in GaAs quantum dots

TL;DR

This paper investigates how heavy hole-light hole coupling affects optical selection rules in GaAs quantum dots, revealing strong mixing effects due to quantum dot asymmetry, with implications for quantum dot optical properties.

Contribution

It demonstrates the strong heavy hole-light hole mixing in GaAs quantum dots and provides a method to quantify this mixing using emission polarization analysis and k·p theory.

Findings

Strong heavy hole-light hole mixing observed in GaAs quantum dots

Quantum dot asymmetry causes significant symmetry reduction effects

Analytical modeling extracts the degree of hole mixing from emission data

Abstract

We report strong heavy hole-light mixing in GaAs quantum dots grown by droplet epitaxy. Using the neutral and charged exciton emission as a monitor we observe the direct consequence of quantum dot symmetry reduction in this strain free system. By fitting the polar diagram of the emission with simple analytical expressions obtained from k$\cdot$p theory we are able to extract the mixing that arises from the heavy-light hole coupling due to the geometrical asymmetry of the quantum dot.