Dense coding scheme using superpositions of Bell-states and its NMR implementation  

作　　者：ZHANG Jingfu, XIE Jingyi, DENG Zhiwei & LU Zhiheng Key Laboratory for Quantum Information and Measurements, Department of Physics, Tsinghua University, Beijing 100084, China Center for Quantum Information, Tsinghua University, Beijing 100084, China Department of Materials Science and Engineering, Beijing Normal University, Beijing 100875, China Testing and Analytical Center, Beijing Normal University, Beijing 100875, China Department of Physics, Beijing Normal University, Beijing 100875, China 

出　　处：《Science China(Physics,Mechanics & Astronomy)》2005年第1期57-67,共11页中国科学：物理学、力学、天文学（英文版）

基　　金：We are grateful to Professor Long Guilu and Mr.Liu Xiaoshu for helpful discussions.This work was supported by the National Natural Science Foundation of China(Grant No.10374010);the China Postdoctoral Science Foundation.

摘　　要：Dense coding using superpositions of Bell-states is proposed. The generalized Grover's algorithm is used to prepare the initial entangled states, and the reverse process of the quantum algorithm is used to determine the entangled state in the decoding measurement. Compared with the previous schemes, the superpositions of two Bell-states are exploited. Our scheme is demonstrated using a nuclear magnetic resonance (NMR)quantum computer. The corresponding manipulations are obtained. Experimental results show a good agreement between theory and experiment. We also generalize the scheme to transmit eight messages by introducing an additional two-state system.Dense coding using superpositions of Bell-states is proposed. The generalized Grover's algorithm is used to prepare the initial entangled states, and the reverse process of the quantum algorithm is used to determine the entangled state in the decoding measurement. Compared with the previous schemes, the superpositions of two Bell-states are exploited. Our scheme is demonstrated using a nuclear magnetic resonance (NMR) quantum computer. The corresponding manipulations are obtained. Experimental results show a good agreement between theory and experiment. We also generalize the scheme to transmit eight messages by introducing an additional two-state system.

关 键 词：DENSE coding  SUPERPOSITIONS of Bell-states  GENERALIZED Grover's algorithm  NUCLEAR magnetic res-onance  QUANTUM computer. 

分 类 号：TN911[电子电信—通信与信息系统]