Asynchronous Routing for Multipartite Entanglement in Quantum Networks

TL;DR

This paper extends an asynchronous routing protocol to efficiently generate multipartite GHZ entanglement in quantum networks, outperforming traditional methods especially with longer coherence times.

Contribution

It introduces an asynchronous, local-knowledge-based routing scheme for multipartite entanglement, enhancing rates over synchronous approaches.

Findings

Asynchronous protocol outperforms synchronous methods in entanglement rates.

Performance improves with increasing coherence times.

Method scalable to larger multipartite GHZ states.

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.