论文标题
复杂量子网络的量子通信能力过渡
Quantum communication capacity transition of complex quantum networks
论文作者
论文摘要
量子网络是启用分布式量子信息处理的关键。随着单链路通信速率随距离呈指数衰减，以实现可靠的端到端量子通信，因此节点的数量需要随着网络规模而增加。对于高度连接的网络，我们确定能力的阈值转变，因为网络节点的密度增加---低于临界密度，速率几乎为零，而高于阈值，速率随密度的线性增加。令人惊讶的是，由于量子网络启用了多路路由，两个节点之间的典型通信能力与它们之间的距离无关。相反，对于较少连接的网络（例如无标度网络），随着节点数量的增加，端到端容量会饱和到常数，并且始终会随着距离而衰减。我们的结果基于容量评估，因此，可观容量的最小密度要求适用于量子网络的任何一般协议。
Quantum network is the key to enable distributed quantum information processing. As the single-link communication rate decays exponentially with the distance, to enable reliable end-to-end quantum communication, the number of nodes needs to grow with the network scale. For highly connected networks, we identify a threshold transition in the capacity as the density of network nodes increases---below a critical density, the rate is almost zero, while above the threshold the rate increases linearly with the density. Surprisingly, above the threshold the typical communication capacity between two nodes is independent of the distance between them, due to multi-path routing enabled by the quantum network. In contrast, for less connected networks such as scale-free networks, the end-to-end capacity saturates to constants as the number of nodes increases, and always decays with the distance. Our results are based on capacity evaluations, therefore the minimum density requirement for an appreciable capacity applies to any general protocols of quantum networks.
