Robust and Scalable Scheme to Generate Large-Scale Entanglement Webs

TL;DR

This paper presents a robust, scalable method for generating large-scale entanglement webs among quantum nodes using linear optics and postselection, enabling efficient creation of large N-qubit W states with manageable overhead.

Contribution

The authors introduce a scalable scheme for generating large N-qubit W states among separated quantum nodes, extending previous methods with improved efficiency and robustness.

Findings

Supports generation of arbitrarily large N-qubit W states

Uses a quasi-polynomial overhead of approximately 2^{O[(log N)^2]}

The breeding process is simple, efficient, and adaptable to other physical systems

Abstract

We propose a robust and scalable scheme to generate an $N$-qubit $W$ state among separated quantum nodes (cavity-QED systems) by using linear optics and postselections. The present scheme inherits the robustness of the Barrett-Kok scheme [Phys. Rev. A {\bf 71}, 060310(R) (2005)]. The scalability is also ensured in the sense that an arbitrarily large $N$-qubit $W$ state can be generated with a quasi-polynomial overhead $\sim 2^{O[(\log_2 N)^2]}$. The process to breed the $W$ states, which we introduce to achieve the scalability, is quite simple and efficient, and can be applied for other physical systems.