Quantum cloning with multicopy in d-dimensions  

作　　者：ZHANG WenHai YU LongBao YANG Ming CAO ZhuoLiang 

机构地区：[1]Department of Physics, Huainan Normal University, Huainan 232038, China [2]Department of Physics and Electronic Engineering, Hefei Teachers College, Hefei 230061, China [3]School of Physics and Material Science, Anhui University, Hefei 230039, China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2011年第12期2217-2224,共8页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No.10704001);the Natural Science Foundation of the Education Department of Anhui Province of China (Grant Nos.KJ2010ZD08 and KJ2010B204);the Doctor Research Start-Up Program of Huainan Normal University

摘　　要：The explicit transformations of the 1→ 3 optimal universal quantum cloning and the optimal phase-covariant quantum cloning in d-dimensions are presented, and the dimensionalities of their ancillary systems are both d-dimensions. As d→∞ , their clone fidelities move toward 1/3, showing a classical limit for the fidelity of quantum cloning. Based on the reduction of the unitary transformation of quantum cloning, the transformation of the 1→M=d+1 optimal economical phase-covariant quantum cloning in d-dimensions is derived, and the clone fidelity is covered by the theoretical value.The explicit transformations of the 1→ 3 optimal universal quantum cloning and the optimal phase-covariant quantum cloning in d-dimensions are presented, and the dimensionalities of their ancillary systems are both d-dimensions. As d→ ∞ , their clone fidelities move toward 1/3, showing a classical limit for the fidelity of quantum cloning. Based on the reduction of the unitary transformation of quantum cloning, the transformation of the 1→M=d＋1 optimal economical phase-covariant quantum cloning in d-dimensions is derived, and the clone fidelity is covered by the theoretical value.

关 键 词：quantum cloning universal quantum cloning phase-covariant quantum cloning economical phase-covariant quantum cloning 

分 类 号：O413[理学—理论物理] Q785[理学—物理]