Experimental estimation of entanglement at the quantum limit

TL;DR

This paper demonstrates an experiment that estimates the entanglement of two-qubit mixed photon states with the highest possible precision dictated by quantum mechanics, advancing quantum measurement techniques.

Contribution

It introduces an experimental method to measure entanglement at the quantum limit, improving the accuracy of entanglement quantification in quantum systems.

Findings

Achieved measurement precision at the quantum limit for entanglement estimation.

Validated the experimental approach on a family of two-qubit mixed photon states.

Enhanced understanding of fundamental quantum measurement bounds.

Abstract

Entanglement is the central resource of quantum information processing and the precise characterization of entangled states is a crucial issue for the development of quantum technologies. This leads to the necessity of a precise, experimental feasible measure of entanglement. Nevertheless, such measurements are limited both from experimental uncertainties and intrinsic quantum bounds. Here we present an experiment where the amount of entanglement of a family of two-qubit mixed photon states is estimated with the ultimate precision allowed by quantum mechanics.