Complete set of operational measures for the characterization of 3-qubit entanglement

TL;DR

This paper introduces a new way to measure and classify three-qubit entanglement using operational measures derived from a novel state decomposition, linking entanglement generation and content.

Contribution

It presents a unique five-parameter decomposition for 3-qubit states and shows these parameters are determined by bipartite entanglement measures, providing a clear physical interpretation.

Findings

Parameters uniquely determine entanglement measures

Classification aligns with local operations and classical communication

Decomposition offers operational insight into 3-qubit entanglement

Abstract

We characterize the entanglement contained in a pure three-qubit state via operational entanglement measures. To this end we derive a new decomposition for arbitrary 3-qubit states which is characterized by five parameters (up to local unitary operations). We show that these parameters are uniquely determined by bipartite entanglement measures. These quantities measure on the one hand the entanglement required to generate the state and on the other hand the entanglement contained in the state and have a clear physical meaning. Moreover, we show that the classification of states obtained in this way is strongly related to the one obtained when considering general local operations and classical communication.