We propose a simple scheme for expanding a polarization-entangled W state. By mixing a single photon and one of the photons in an n-photon W state at a polarization-dependent beam splitter (PDBS), we can obtain an (n+1)-photon W state after post-selection. Our scheme also opens the door for generating n-photon W states using single photons and linear optics.
Cite
@article{arxiv.0810.2705,
title = {Simple scheme for expanding a polarization-entangled W state by adding one photon},
author = {Yan-Xiao Gong and Xu-Bo Zou and Yun-Feng Huang and Guang-Can Guo},
journal= {arXiv preprint arXiv:0810.2705},
year = {2009}
}