Deterministic Local Expansion of W States

TL;DR

This paper introduces a deterministic, resource-efficient, all-optical method for preparing W states of arbitrary size, enhancing their practical use in quantum networks without probabilistic limitations.

Contribution

It presents the first deterministic, local, and entanglement-free scheme for generating large W states, advancing quantum network capabilities.

Findings

Successfully prepares W states of arbitrary size

Operates deterministically without prior entanglement

Uses an all-optical setup for implementation

Abstract

In large quantum systems multipartite entanglement can be found in many inequivalent classes under local operations and classical communication. Preparing states of arbitrary size in different classes is important for performing a wide range of quantum protocols. W states, in particular, constitute a class with a variety of quantum networking protocols. However, all known schemes for preparing W states are probabilistic, with resource requirements increasing at least sub-exponentially. We propose a deterministic scheme for preparing W states that requires no prior entanglement and can be performed locally. We introduce an all-optical setup that can efficiently prepare W states of arbitrary size. Our scheme advances the use of W states in real-world quantum networks and could be extended to other physical systems.