  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.
