A quantum network distributes quantum entanglements between remote nodes, which is key to many quantum applications. However, unavoidable noise in quantum operations could lead to both low throughput and low quality of entanglement distribution. This paper aims to address the simultaneous exponential degradation in throughput and quality in a buffered multi-hop quantum network. Based on an end-to-end fidelity model with worst-case (isotropic) noise, we formulate the high-fidelity remote entanglement distribution problem for a single source-destination pair, and prove its NP-hardness. To address the problem, we develop a fully polynomial-time approximation scheme for the control plane of the quantum network, and a distributed data plane protocol that achieves the desired long-term throughput and worst-case fidelity based on control plane outputs. To evaluate our algorithm and protocol, we develop a discrete-time quantum network simulator. Simulation results show the superior performance of our approach compared to existing fidelity-agnostic and fidelity-aware solutions.
翻译:在量子网络中,远程节点之间进行量子纠缠分发是许多量子应用的关键。然而,量子操作中难以避免的噪声可能导致纠缠分发的吞吐量和质量同时指数级下降。本文旨在解决缓冲多跳量子网络中吞吐量和质量同时下降的问题。基于具有最坏情况下(各向同性)噪声的端到端保真度模型,我们为单个源目标对制定高保真度远程纠缠分发问题,并证明其是NP难问题。为了解决问题,我们开发了一种完全多项式时间逼近方案,用于量子网络的控制平面,并开发了基于控制平面输出实现所需的长期吞吐量和最坏情况下保真度的分布式数据平面协议。为了评估我们的算法和协议,我们开发了一个离散时间量子网络模拟器。模拟结果显示我们的方法相比现有的保真度不可知和保真度可知的解决方案具有卓越性能。