We present an experiment of preparing Werner state via spontaneous parametric down-conversion and controlled decoherence of photons in this paper. In this experiment two independent BBO (beta-barium borate) crystals are used to produce down-conversion light beams, which are mixed to prepare Werner state.
Cite
@article{arxiv.quant-ph/0206166,
title = {Experimental preparation of Werner state via spontaneous parametric down-conversion},
author = {Yong-Sheng Zhang and Yun-Feng Huang and Chuan-Feng Li and Guang-Can Guo},
journal= {arXiv preprint arXiv:quant-ph/0206166},
year = {2009}
}