We study the optimal entanglement witness with respect to multiqubits W-states. We show such entanglement witnesses can be used to distinguish genuine entangled states, different biseparable states and fully separable states.
@article{arxiv.0906.1507,
title = {Multiqubits Entanglement Based on Optimal Witness},
author = {Ming-Jing Zhao and Zhi-Xi Wang and Shao-Ming Fei},
journal= {arXiv preprint arXiv:0906.1507},
year = {2015}
}