Performance metrics for the continuous distribution of entanglement in multi-user quantum networks

TL;DR

This paper introduces new performance metrics for analyzing the steady-state distribution of entanglement in multi-user quantum networks, emphasizing the importance of consumption rate over fidelity in protocol performance.

Contribution

It proposes virtual neighborhood size and node degree as metrics, and formulates a multi-objective optimization problem to evaluate entanglement distribution protocols.

Findings

Consumption rate impacts performance more than fidelity.

Metrics can assess large-scale quantum network protocols.

Optimization for tree topology demonstrates the approach.

Abstract

Entangled states shared among distant nodes are frequently used in quantum network applications. When quantum resources are abundant, entangled states can be continuously distributed across the network, allowing nodes to consume them whenever necessary. This continuous distribution of entanglement enables quantum network applications to operate continuously while being regularly supplied with entangled states. Here, we focus on the steady-state performance analysis of protocols for continuous distribution of entanglement. We propose the virtual neighborhood size and the virtual node degree as performance metrics. We utilize the concept of Pareto optimality to formulate a multi-objective optimization problem to maximize the performance. As an example, we solve the problem for a quantum network with a tree topology. One of the main conclusions from our analysis is that the entanglement consumption rate has a greater impact on the protocol performance than the fidelity requirements. The metrics that we establish in this manuscript can be utilized to assess the feasibility of entanglement distribution protocols for large-scale quantum networks.