Photon correlation in GaAs self-assembled quantum dots

TL;DR

This study demonstrates nearly perfect single-photon emission from a GaAs quantum dot under pulsed excitation, with photon correlation revealing complex exciton interactions at higher excitation levels.

Contribution

It provides new insights into photon correlation behaviors in GaAs quantum dots, including the observation of exciton complexes and their emission dynamics.

Findings

Single-photon emission observed at 670 nm in GaAs QDs

Photon correlation shows bunching and antibunching behaviors

Multiple PL lines indicate formation of exciton complexes

Abstract

We report on photon coincidence measurement in a single GaAs self-assembled quantum dot (QD) using a pulsed excitation light source. At low excitation, when a neutral exciton line was present in the photoluminescence (PL) spectrum, we observed nearly perfect single photon emission from an isolated QD at 670 nm wavelength. For higher excitation, multiple PL lines appeared on the spectra, reflecting the formation of exciton complexes. Cross-correlation functions between these lines showed either bunching or antibunching behavior, depending on whether the relevant emission was from a biexciton cascade or a charged exciton recombination.