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

摘要

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 10K 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. We study the temperature dependent device characteristics and estimate the maximum operation temperature to be similar to 65K, which is essentially limited by the weak 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.