We propose an effective protocol for preparation of four-photon polarization-entangled decoherence-free states with quantum nondemolition detectors. The protocol is based on optical elements, single polarization photons, and cross-Kerr nonlinearity, which are feasible with existing experimental technology. Compared with previous protocols, the present one is to replace the entangled-state resources with much simpler single-photon resources and has a higher success probability. All these advantages make this protocol more efficient and more convenient than others in the applications in quantum communication.
© 2013 Optical Society of America
Original Manuscript: December 3, 2012
Revised Manuscript: December 15, 2012
Manuscript Accepted: December 15, 2012
Published: January 22, 2013
Yan Xia, Mei Lu, Jie Song, Pei-Min Lu, and He-Shan Song, "Effective protocol for preparation of four-photon polarization-entangled decoherence-free states with cross-Kerr nonlinearity," J. Opt. Soc. Am. B 30, 421-427 (2013)