Efficient entanglement purification in quantum repeaters  

作　　者：盛宇波 周澜 程维文 巩龙龑 赵生妹 郑宝玉 

机构地区：[1]Institute of Signal Processing Transmission,Nanjing University of Posts and Telecommunications [2]College of Telecommunications & Information Engineering,Nanjing University of Posts and Telecommunications [3]Key Laboratory of Broadband Wireless Communication and Sensor Network Technology of Ministry of Education,Nanjing University of Posts and Telecommunications [4]Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences

出　　处：《Chinese Physics B》2012年第3期67-73,共7页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant Nos. 11104159 and 10904074);the Scientific Research Foundation of Nanjing University of Posts and Telecommunications, China (Grant No. NY211008);the University Natural Science Research Foundation of Jiangsu Province, China (Grant No. 11KJA510002);the Open Research Fund of Key Labof Broadband Wireless Communication and Sensor Network Technology (Nanjing University of Posts and Telecommunications) of Ministry of Education, China;the Priority Academic Program Development Fund of Jiangsu Higher Education Institutions,China

摘　　要：We present an efficient entanglement purification protocol （EPP） with controlled-not （CNOT） gates and linear optics. With the CNOT gates, our EPP can reach a higher fidelity than the conventional one. Moreover, it does not require the fidelity of the initial mixed state to satisfy 1 2. If the initial state is not entangled, it still can be purified. With the linear optics, this protocol can get pure maximally entangled pairs with some probabilities. Meanwhile, it can be used to purify the entanglement between the atomic ensembles in distant locations. This protocol may be useful in long-distance quantum communication.We present an efficient entanglement purification protocol （EPP） with controlled-not （CNOT） gates and linear optics. With the CNOT gates, our EPP can reach a higher fidelity than the conventional one. Moreover, it does not require the fidelity of the initial mixed state to satisfy 1 2. If the initial state is not entangled, it still can be purified. With the linear optics, this protocol can get pure maximally entangled pairs with some probabilities. Meanwhile, it can be used to purify the entanglement between the atomic ensembles in distant locations. This protocol may be useful in long-distance quantum communication.

关 键 词：quantum communication ENTANGLEMENT entanglement purification quantum repeater 

分 类 号：O431.2[机械工程—光学工程]