Optimal verification of entanglement in a photonic cluster state experiment

TL;DR

This paper demonstrates methods for quantifying and scaling entanglement in photonic cluster states using entanglement measures, with experimental results on four- and six-qubit states entangled in polarization and momentum.

Contribution

It introduces a practical approach for entanglement quantification and explores how entanglement bounds scale with incomplete tomographic data in realistic experiments.

Findings

Successfully quantified entanglement in four- and six-qubit photonic cluster states.

Analyzed the impact of incomplete tomography on entanglement bounds.

Provided insights into entanglement scaling in experimental conditions.

Abstract

We report on the quantification of entanglement by means of entanglement measures on a four- and a six- qubit cluster state realized by using photons entangled both in polarization and linear momentum. This paper also addresss the question of the scaling of entanglement bounds from incomplete tomographic information on the density matrix under realistic experimental conditions.