Generation and use of highly entangled photons from semiconductor quantum dots.

Entanglement is one of the most peculiar phenomena in quantum science and a key resource for quantum technologies. More than two decades after the initial proposal, semiconductor quantum dots (QDs) are now beginning to outperform other sources for the generation of entangled photon pairs. Among different material systems, QDs in the $(Al)GaAs$ platform have demonstrated the highest degree of polarization entanglement to date together with other appealing features for quantum science and technology. In this contribution, we will discuss the properties of GaAs QDs obtained by the droplet etching method and present recent results relevant to their application in quantum communication, $i.e.$, entanglement-based quantum key distribution, quantum teleportation and entanglement swapping.