  This paper studies the capacity of the quantum switch for two decoherence
models: when link-level entanglements last (i) for a time slot, or (ii) until
they are used to serve a request (i.e., there is no decoherence). The two
models are important as they set lower and upper bounds on the capacity region
for any other decoherence model. The paper's contributions are to characterize
the switch capacity region for both decoherence models and to propose
throughput-optimal policies based on gradient descent.
