Multiparty Entanglement Routing in Quantum Networks

TL;DR

This paper introduces a protocol for efficiently distributing maximally entangled states among multiple users in quantum networks of any topology, using local measurements and minimal memory, improving existing bipartite routing methods.

Contribution

It presents a novel protocol based on graph state formalism for multiparty entanglement routing with minimal assumptions and resources, enhancing bipartite routing strategies using majorization.

Findings

Protocol successfully extracts GHZ states for any number of parties.

Improved bipartite routing algorithms for specific network architectures.

Utilizes graph symmetry and majorization to optimize path selection.

Abstract

Distributing entanglement among multiple users is a fundamental problem in quantum networks, requiring an efficient solution. In this work, a protocol is proposed for extracting maximally entangled (GHZn) states for any number of parties in quantum networks of arbitrary topology. It is based on the graph state formalism and requires minimal assumptions on the network state. The protocol only requires local measurements at the network nodes and just a single qubit memory per user. Existing protocols on bipartite entanglement routing are also improved for specific nearest-neighbor network architectures. To this end, the concept of majorization is utilized to establish a hierarchy among different paths in a network based on their efficacy. This approach utilizes the symmetry of the underlying graph state to obtain better-performing algorithms.