Segmented Entanglement Establishment for Throughput Maximization in Quantum Networks

There are two conventional methods to establish an entanglement connection in a Quantum Data Network (QDN). One is to create single-hop entanglement links first and then connect them with quantum swapping, and the other is for-warding one of the entangled photons from one end to the other via all-optical switching at intermediate nodes to directly establish an entanglement connection. Since a photon is easy to be lost during a long distance transmission, all existing works are adopting the former method. However, in a room size network, the success probability of delivering a photon across multiple links via all-optical switching is not that low. In addition, with an all-optical switching technique, we can save quantum memory at the intermediate nodes. Accordingly, we are expecting to establish significantly more entanglement connections with limited quantum resources by first creating entanglement segments, each spanning multiple quantum links, using all-optical switching, and then connecting them with quantum swapping.In this paper, we design SEE, a Segmented Entanglement Establishment approach that seamlessly integrates quantum swapping and all-optical switching to maximize quantum network throughput. SEE first creates entanglement segments over one or multiple quantum links with all-optical switching, and then connect them with quantum swapping. It is clear that an entanglement link is only a special entanglement segment. Accordingly, SEE can theoretically outperform conventional entanglement link based approaches. Large scale simulations show that SEE can achieve up to 100.00% larger throughput compared with the state-of-the-art entanglement link based approach, i.e., REPS.