Routing Entanglement in Complex Quantum Networks Using GHZ States

TL;DR

This paper explores entanglement routing in complex quantum networks using GHZ states, proposing a hybrid strategy that outperforms traditional methods in certain network topologies.

Contribution

It introduces a hybrid GHZ-BSM routing strategy considering measurement success probabilities and extends analysis to complex and real-world networks.

Findings

Hybrid GHZ-BSM routing outperforms BSM routing in square grid networks.

Naive GHZ routing yields lower rates due to measurement success probabilities.

Advanced strategies with global information are needed for complex networks.

Abstract

Distributing entanglement to distant parties in a network is a central task in quantum information processing and quantum networking. The sensitivity of entangled states to loss necessitates the use of entanglement routing strategies. Recently, a routing strategy using Greenberger-Horne-Zeilinger (GHZ) measurements instead of Bell state measurements (BSM) has been proposed. We further this direction of research by explicitly considering the varying measurement success probabilities of GHZ measurements. Moreover, we extend the analysis beyond square grid networks to complex network models such as Waxman networks and scale-free networks, as well as SURFnet, a real-world network topology in the Netherlands. Taking into account the varying success probabilities, naive application of GHZ routing achieves rates much lower than the conventional BSM routing. Instead, we propose a hybrid GHZ-BSM routing strategy. The hybrid GHZ-BSM routing strategy outperforms BSM routing in square grid networks. In other networks, however, more sophisticated adaptations using global information are required.