Continuous entanglement distribution over a transnational 248 km fiber link

Continuous entanglement distribution over a transnational 248 km fiber link Abstract Reliable long-distance distribution of entanglement is a key technique for many quantum applications, most notably quantum key distribution. Here, we present a continuously working, trusted-node free international link between Austria and Slovakia, directly distributing polarization-entangled photon pairs via 248 km of deployed telecommunication fiber. Despite 79 dB loss, we observe stable detected pair rates o...