Distributing quantum state and entanglement between distant nodes is a crucial task in distributed quantum information processing on large-scale quantum networks. Quantum network coding provides an alternative solution for quantum-state distribution, especially when the bottleneck problems must be considered and high communication speed is required. Here, we report the first experimental realization of quantum network coding on the butterfly network. With the help of prior entanglements shared between senders, two quantum states can be transmitted perfectly through the butterfly network. We demonstrate this protocol by employing eight photons generated via spontaneous parametric downconversion. We observe cross-transmission of single-photon states with an average fidelity of 0.9685 ± 0.0013, and that of two-photon entanglement with an average fidelity of 0.9611 ± 0.0061, both of which are greater than the theoretical upper bounds without prior entanglement.

在远距离节点之间分布量子状态和纠缠是大规模量子网络上分布式量子信息处理中的关键任务。量子网络编码为量子态分布提供了另一种解决方案，尤其是在必须考虑瓶颈问题并且需要高通信速度的情况下。在这里，我们报告了在蝶形网络上进行量子网络编码的第一个实验性实现。借助于发送者之间的先验纠缠，可以通过蝶形网络完美地传输两个量子态。我们通过使用通过自发参数下转换生成的八个光子来演示此协议。我们观察到单光子态的交叉传输的平均保真度为0.9685±0.0013，