Linear optical scheme to demonstrate genuine multipartite entanglement for single-particle W states

TL;DR

This paper proposes linear optical schemes using detectors and beam splitters to verify genuine multipartite entanglement in single-particle W states, with efficiency thresholds for experimental feasibility.

Contribution

It introduces two experimental schemes for entanglement detection in W states, optimizing measurement settings and efficiency requirements.

Findings

Single-measurement scheme detects entanglement beyond 1-1/N efficiency.

Multi-measurement scheme lowers efficiency threshold for detection.

Both schemes are feasible with current optical technology.

Abstract

We consider the method of entanglement witness operator to verify genuine multipartite entanglement for single-particle W states involving N parties. In particular, linear optical schemes using photo detectors and beam splitters are proposed to implement two different types of witness operator in experiment. The first scheme that requires only a single measurement setting is shown to detect genuine multipartite entanglement for the overall efficiency beyond 1-1/N. On the other hand, the second scheme with N+1 measurement settings achieves success at a significantly lowered efficiency than 1-1/N.