Long-distance quantum communication presents a significant challenge as maintaining the fidelity of qubits can be difficult. This issue can be addressed through the use of quantum repeaters to transmit entanglement information through Bell measurements. However, despite its necessity to enable wide-area quantum internet, the deployment cost of quantum repeaters can be prohibitively expensive, thus it is important to develop a quantum repeater deployment model that can strike a balance between cost and effectiveness. In this work, we present novel heuristic models to quickly determine a minimum number of quantum repeaters to deploy in large-scale networks to provide end-to-end connectivity between all end hosts. The results show that, compared to the linear programming approach, the heuristic methods can find near-optimal solutions while reducing the execution time from days to seconds when evaluated against several synthetic and real-world networks such as SURFnet and ESnet. As reliability is key for any network, we also demonstrate that the heuristic method can determine deployment models that can endure up to two link/node failures.

翻译：长距离量子通信面临重大挑战，因为保持量子比特的保真度十分困难。这一问题可通过使用量子中继器传输贝尔测量纠缠信息来解决。然而，尽管量子中继器是实现广域量子互联网所必需的，但其部署成本可能高得令人望而却步，因此开发一种能在成本与效能之间取得平衡的量子中继器部署模型至关重要。在本研究中，我们提出了新颖的启发式模型，能够快速确定在大规模网络中需要部署的最小量子中继器数量，以实现所有终端主机之间的端到端连接。结果表明，与线性规划方法相比，启发式方法在针对SURFnet和ESnet等多个合成及真实网络进行评估时，能够找到接近最优的解决方案，同时将执行时间从数天缩短至数秒。鉴于可靠性是任何网络的关键特性，我们还展示了启发式方法能够确定可承受最多两个链路/节点故障的部署模型。