A Throughput Optimal Scheduling Policy for a Quantum Switch

TL;DR

This paper introduces a throughput optimal scheduling policy for a quantum switch that manages entanglement creation and distribution among users, ensuring stability within the capacity region.

Contribution

It proposes a Max-Weight scheduling policy for quantum switches and proves its stability for all feasible arrival rates, advancing quantum network management.

Findings

Max-Weight policy stabilizes the switch within the capacity region.

Characterization of the capacity region for the quantum switch.

Numerical results support the theoretical analysis.

Abstract

We study a quantum switch that creates shared end-to-end entangled quantum states to multiple sets of users that are connected to it. Each user is connected to the switch via an optical link across which bipartite Bell-state entangled states are generated in each time-slot with certain probabilities, and the switch merges entanglements of links to create end-to-end entanglements for users. One qubit of an entanglement of a link is stored at the switch and the other qubit of the entanglement is stored at the user corresponding to the link. Assuming that qubits of entanglements of links decipher after one time-slot, we characterize the capacity region, which is defined as the set of arrival rates of requests for end-to-end entanglements for which there exists a scheduling policy that stabilizes the switch. We propose a Max-Weight scheduling policy and show that it stabilizes the switch for all arrival rates that lie in the capacity region. We also provide numerical results to support our analysis.