We demonstrate a method of creating photonic two-dimensional cluster states that is considerably more efficient than previously proposed approaches. Our method uses only local unitaries and type-I fusion operations. The increased efficiency of our method compared to previously proposed constructions is obtained by identifying and exploiting local equivalence properties inherent in cluster states.
@article{arxiv.quant-ph/0512110,
title = {Efficient Construction of Photonic Quantum Computational Clusters},
author = {Gerald Gilbert and Michael Hamrick and Yaakov S. Weinstein},
journal= {arXiv preprint arXiv:quant-ph/0512110},
year = {2009}
}