Polarization fine-structure and enhanced single-photon emission of self-assembled lateral InGaAs quantum dot molecules embedded in a planar micro-cavity

TL;DR

This paper demonstrates enhanced single-photon emission from lateral InGaAs quantum dot molecules embedded in a micro-cavity, with controllable emission energies and observed polarization fine-structure splitting.

Contribution

It reports the integration of quantum dot molecules in a micro-cavity, achieving significant emission enhancement and controllability, along with the observation of polarization fine-structure splitting.

Findings

30-fold increase in single-photon emission rate

Switchable emission energies via lateral electric field

Detection of polarization fine-structure splitting around 10 micro-eV

Abstract

Single lateral InGaAs quantum dot molecules have been embedded in a planar micro-cavity in order to increase the luminescence extraction efficiency. Using a combination of metal-organic vapor phase and molecular beam epitaxy samples could be produced that exhibit a 30 times enhanced single-photon emission rate. We also show that the single-photon emission is fully switchable between two different molecular excitonic recombination energies by applying a lateral electric field. Furthermore, the presence of a polarization fine-structure splitting of the molecular neutral excitonic states is reported which leads to two polarization-split classically correlated biexciton exciton cascades. The fine-structure splitting is found to be on the order of 10 micro-eV.