Evaluation of entanglement measures by a single observable

TL;DR

This paper introduces a method to estimate various bipartite entanglement measures using a single observable, enabling practical entanglement quantification from experimental data.

Contribution

The authors develop analytical lower bounds for multiple entanglement measures based on a single observable, simplifying experimental estimation of entanglement.

Findings

Lower bounds can be calculated analytically from a single observable expectation value.

The method applies to arbitrary finite-dimensional bipartite states.

Experimental data demonstrates the effectiveness of the bounds.

Abstract

We present observable lower bounds for several bipartite entanglement measures including entanglement of formation, geometric measure of entanglement, concurrence, convex-roof extended negativity, and G-concurrence. The lower bounds facilitate estimates of these entanglement measures for arbitrary finite-dimensional bipartite states. Moreover, these lower bounds can be calculated analytically from the expectation value of a single observable. Based on our results, we use several real experimental measurement data to get lower bounds of entanglement measures for these experimentally realized states. In addition, we also study the relations between entanglement measures.