Thorough evaluation of GHZ generation protocols using conference key agreement

TL;DR

This paper compares various protocols for generating GHZ states in quantum networks, evaluating their performance in conference key agreement, and introduces a new optimal protocol for large networks based on realistic NV center parameters.

Contribution

It provides an extensive comparison of GHZ generation protocols under realistic conditions and introduces a new protocol optimized for large quantum networks.

Findings

The new protocol outperforms existing ones for large networks.

Realistic parameters significantly influence protocol performance.

The best protocol for high node counts is introduced in this work.

Abstract

The generation of GHZ states in quantum networks is a key element for the realization of several quantum information tasks. Given the complexity of the implementation of such generation, it is not easy to find an unambigous proof for an optimal protocol. Motivated by recent improvements in NV center manipulation, we present and compare an extensive list of protocols for generating GHZ states using realistic parameters. Furthermore, in order to establish the goodness of the various protocols, we test them on a specific application, i.e. conference key agreement. We show that for an high number of nodes the best protocol is one presented here for the first time.