  Quantum switches are critical components in quantum networks, distributing
maximally entangled pairs among end nodes by entanglement swapping. In this
work, we design protocols that schedule entanglement swapping operations in
quantum switches. Entanglement requests randomly arrive at the switch, and the
goal of an entanglement swapping protocol is to stabilize the quantum switch so
that the number of unfinished entanglement requests is bounded with a high
probability. We determine the capacity region for the rates of entanglement
requests and develop entanglement swapping protocols to stabilize the switch.
Among these protocols, the on-demand protocols are not only computationally
efficient, but also achieve high fidelity and low latency demonstrated by
results obtained using a quantum network discrete event simulator.
