We study the problem of operating a quantum switch with memory constraints. In particular, the switch has to allocate quantum memories to clients to generate link-level entanglements (LLEs), and then use these to serve end-to-end entanglements requests. The paper's main contributions are (i) to characterize the switch's capacity region, and (ii) to propose a memory allocation policy (MEW) that is throughput optimal. The worst-case time complexity of MEW is exponential on the system parameters. However, when the requests are bipartite and the LLE attempts are always successful, we propose a variant of MEW (MEW2) that has polynomial time complexity. We evaluate the proposed policies numerically and illustrate their performance depending on the requests arrivals characteristics and the time available to obtain a memory allocation.

翻译：我们研究了在内存约束条件下操作量子交换机的问题。具体而言，交换机需将量子内存分配给客户端以生成链路级纠缠（LLEs），进而利用这些纠缠服务于端到端的纠缠请求。本文的主要贡献在于：（i）刻画了交换机的容量区域；（ii）提出了一种吞吐量最优的内存分配策略（MEW）。MEW在最坏情况下的时间复杂度为系统参数的指数级。然而，当请求为二分且LLE尝试总是成功时，我们提出了一种MEW的变体（MEW2），其具有多项式时间复杂度。我们对所提策略进行了数值评估，并展示了其性能随请求到达特性及获得内存分配可用时间的变化情况。