Asynchronous Routing for Multipartite Entanglement in Quantum Networks

2026-03-29

AI Summary

This work addresses the challenge of efficiently generating long-distance multipartite entanglement—such as Greenberger–Horne–Zeilinger (GHZ) states—required for advanced quantum network applications, which existing approaches focusing primarily on bipartite entanglement distribution struggle to support. The authors propose an asynchronous tree-based routing protocol that leverages only local link information, extending asynchronous routing mechanisms for the first time to multipartite entanglement scenarios. This protocol enables efficient generation of GHZ states involving three or more parties without requiring global synchronization and incorporates caching of unused entangled resources. By integrating asynchronous entanglement swapping, tree-structured topologies, and local state awareness, the method adapts flexibly to diverse network architectures. Experimental results demonstrate that, in tripartite GHZ state distribution, the proposed scheme achieves significantly higher entanglement generation rates than conventional synchronous protocols, with performance gains becoming more pronounced as quantum memory coherence times increase, thereby confirming its efficiency and scalability.

Abstract

In quantum networks, one way to communicate is to distribute entanglements through swapping at intermediate nodes. Most existing work primarily aims to create efficient two-party end-to-end entanglement over long distances. However, some scenarios also require remote multipartite entanglement for applications such as quantum secret sharing and multi-party computation. Our previous study improved end-to-end entanglement rates using an asynchronous, tree-based routing scheme that relies solely on local knowledge of entanglement links, conserving unused entanglement and avoiding synchronous operations. This article extends this approach to multipartite entanglements, particularly the three-party Greenberger-Horne-Zeilinger (GHZ) states. It shows that our asynchronous protocol outperforms traditional synchronous methods in entanglement rates, especially as coherence times increase. This approach can also be extended to four-party and larger multipartite GHZ states, highlighting the effectiveness and adaptability of asynchronous routing for multipartite scenarios across various network topologies.

Problem

• multipartite entanglement
• quantum networks
• GHZ states
• asynchronous routing
• entanglement distribution

Innovation

• asynchronous routing
• multipartite entanglement
• GHZ states
• quantum networks
• entanglement swapping