The local content of bipartite qubit correlations

TL;DR

This paper determines the exact local content of correlations in a broad class of two-qubit pure states using a new decomposition method, advancing understanding of quantum correlations.

Contribution

It introduces a new EPR2 decomposition that calculates the local content for a wide range of two-qubit pure states, with potential extensions to all such states.

Findings

Exact local content pL(theta)=cos(2theta) for states psi(theta)

New EPR2 decomposition method developed

Insights on extending results to all two-qubit pure states

Abstract

One of the last open problems concerning two qubits in a pure state is to find the exact local content of their correlation, in the sense of Elitzur, Popescu and Rohrlich (EPR2) [Phys. Lett. A 162, 25 (1992)]. We propose a new EPR2 decomposition that allows us to prove, for a wide range of states psi(theta)=cos(theta)|00>+sin(theta)|11>, that their local content is pL(theta)=cos(2theta). We also share reflections on how to possibly extend our result to all two-qubit pure states.