A Control Architecture for Entanglement Generation Switches in Quantum Networks

Entanglement between quantum network nodes is often produced using intermediary devices- such as heralding stations - as a resource. When scaling quantum networks to many nodes, requiringa dedicated intermediary device for every pair of nodes introduces high costs. Here, we propose a cost-effective architecture to connect many quantum network nodes via a central quantum network hub calledan Entanglement Generation Switch (EGS). The EGS allows multiple quantum nodes to be connected at afixed resource cost, by sharing the resources needed to make entanglement. We propose an algorithm calledthe Rate Control Protocol (RCP) which moderates the level of competition for access to the hub’s resourcesbetween sets of users. We proceed to prove a convergence theorem for rates yielded by the algorithm. Toderive the algorithm we work in the framework of Network Utility Maximization (NUM) and make use ofthe theory of Lagrange multipliers and Lagrangian duality. Our EGS architecture lays the groundwork fordeveloping control architectures compatible with other types of quantum network hubs as well as systemmodels of greater complexity.