Pre-established entanglement distribution algorithm in quantum networks

As the basic principle of quantum networks, quantum entanglement can enable important quantum applications such as teleportation and quantum-key distribution. To realize wide-area quantum communication, entanglement establishment between two remote communication parties is vital, and it requires effective entanglement distribution strategies. Entanglement distribution network models of distributed and centralized entangled pair sources are constructed, based on which two entanglement-distribution algorithms are proposed, i.e., the real-time entanglement distribution (R-TED) algorithm and the pre-established entanglement distribution (P-EED) algorithm, to achieve end-to-end multi-hop entanglement establishment. For the former, the objective is to build long-distance entanglements via hop-by-hop entanglement tentatively and entanglement swapping to finally glue them together. For the latter, which uses pre-established entanglement, entanglements can be established in advance to patch multiple link-level entanglements via entanglement swapping. Simulation results show that as the number of time slots increases, the P-EED algorithm is more efficient and has higher entanglement establishment probability than the R-TED algorithm to establish end-to-end entanglement; while there are fewer memory cells in a quantum memory, such as 10, the R-TED algorithm provides more stable entanglement distribution compared to the P-EED algorithm. (C) 2022 Optica Publishing Group