Quantum networks are complex systems formed by the interaction among quantum processors through quantum channels. Analogous to classical computer networks, quantum networks allow for the distribution of quantum operations among quantum processors. In this work, we describe a Quantum Walk Control Protocol (QWCP) to perform distributed quantum operations in a quantum network. We consider a generalization of the discrete-time coined quantum walk model that accounts for the interaction between quantum walks in the network graph with quantum registers inside the network nodes. QWCP allows for the implementation of networked quantum services, such as distributed quantum computing and entanglement distribution, abstracting hardware implementation and the transmission of quantum information through channels. Multiple interacting quantum walks can be used to propagate entangled control signals across the network in parallel. We demonstrate how to use QWCP to perform distributed multi-qubit controlled gates, which shows the universality of the protocol for distributed quantum computing. Furthermore, we apply the QWCP to the task of entanglement distribution in a quantum network.

翻译：量子网络是通过量子信道连接量子处理器相互作用形成的复杂系统。类似于经典计算机网络，量子网络允许量子运算在量子处理器间分布执行。本研究描述了一种量子行走控制协议（QWCP），用于在量子网络中执行分布式量子运算。我们考虑了离散时间有标记量子行走模型的泛化版本，该模型纳入了网络图中量子行走与网络节点内量子寄存器之间的相互作用。QWCP可实现网络化量子服务（如分布式量子计算和纠缠分发），并抽象了硬件实现及量子信息通过信道的传输过程。多个相互作用的量子行走可并行传播纠缠控制信号穿越整个网络。我们演示了如何利用QWCP执行分布式多量子比特受控门操作，证明了该协议在分布式量子计算中的通用性。此外，我们将QWCP应用于量子网络中的纠缠分发任务。