The (non-)local content in the sense of Elitzur, Popescu, and Rohrlich (EPR2) [Phys. Lett. A 162, 25 (1992)] is a natural measure for the (non-)locality of quantum states. Its computation is in general difficult, even in low dimensions, and is one of the few open questions about pure two-qubit states. We present a complete solution to this long-lasting problem.
@article{arxiv.1204.2982,
title = {The local content of all pure two-qubit states},
author = {Samuel Portmann and Cyril Branciard and Nicolas Gisin},
journal= {arXiv preprint arXiv:1204.2982},
year = {2012}
}