Highly efficient scheme for the preparation of four-photon polarization entangled state via quantum non-demolition measurement with classical feed-forward

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• 作者：Mengzheng Zhu^a ;   ; ^{mzzhu@139.com} ; Chunran Zhao^a ;   ; ^b ; Liu Ye^b ;   ; ^{yeliu@ahu.edu.cn}
• 关键词：Cross-Kerr nonlinearity ; Quantum non-demolition measurement ; Entangled state
• 刊名：Optics Communications
• 出版年：2011
• 出版时间：15 October 2011
• 年：2011
• 卷：284
• 期：22
• 页码：5394-5397
• 全文大小：290 K

文摘

A simple and efficient scheme is proposed to prepare a four-photon entangled state, which can be used as a resource for realizing a controlled-NOT (CNOT) gate pointed out by Gottesman and Chuang [Nature 402 (1999) 390], with the help of the cross-Kerr nonlinearity. The distinct feature of the present scheme is its preparation with near unity success probability and near perfect fidelity. It is not necessary in the present scheme that the cross-Kerr nonlinearity is very large because the weak nonlinearity can be compensated by using a coherent light laser probe beam with very large amplitude. This makes us more confident in the feasibility of the proposed scheme.