# Current-injection quantum-entangled-pair emitter using droplet epitaxial quantum dots on GaAs(111)A

## TL;DR

This paper demonstrates an electrically driven, droplet epitaxial GaAs quantum dot source that generates quantum entangled photon pairs with high fidelity, operable at relatively high temperatures, advancing practical quantum communication technologies.

## Contribution

It introduces a naturally symmetric GaAs quantum dot grown by droplet epitaxy as an efficient source of entangled photon pairs suitable for practical applications.

## Key findings

- Entangled photon pairs with fidelity 0.71 beyond classical limit.
- Quantum entanglement preserved up to ~65 K.
- Charge confinement limits the temperature range.

## Abstract

A source of single photons and quantum entangled photon pairs is a key element in quantum information networks. Here, we demonstrate the electrically driven generation of quantum entangled pairs using a naturally symmetric GaAs quantum dot grown by droplet epitaxy. Coincidence histograms obtained at a temperature of 10 K reveal the generation of quantum entangled pairs that have a fidelity to the Bell pairs of 0.71 +- 0.015, much beyond the classical limit. The quantum nature of the emitted pairs is conserved at temperatures of up to ~65 K, and is essentially limited by the charge carrier confinement in the present dot system. Our study offers a guideline for the fabrication of quantum entangled pair sources suitable for practical use.