中国物理B ›› 2002, Vol. 11 ›› Issue (4): 339-345.doi: 10.1088/1009-1963/11/4/306

• CLASSICAL AREAS OF PHENOMENOLOGY • 上一篇    下一篇

Continuous variable entanglement swapping in a thermal environment

刘金明, 李剑, 郭光灿   

  1. Laboratory of Quantum Communication and Quantum Computation, Department of Physics, University of Science and Technology of China, Hefei 230026, China
  • 收稿日期:2001-08-13 修回日期:2001-11-24 出版日期:2005-06-13 发布日期:2005-06-13
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No 19874056).

Continuous variable entanglement swapping in a thermal environment

Liu Jin-Ming (刘金明), Li Jian (李剑), Guo Guang-Can (郭光灿)   

  1. Laboratory of Quantum Communication and Quantum Computation, Department of Physics, University of Science and Technology of China, Hefei 230026, China
  • Received:2001-08-13 Revised:2001-11-24 Online:2005-06-13 Published:2005-06-13
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No 19874056).

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摘要： With the application of a Wigner function description of a two-mode squeezed state, we study a protocol of continuous variable entanglement swapping in a noisy quantum channel. Assuming that the two initial entangled states are coupled with the same environment, we analyse the quantum state emerging from the swapping and obtain the inseparable condition for the output correlation. It is found that there is more noise resulting from the entanglement swapping than from the direct transmission, no matter what values of displacement gain are chosen.

Abstract: With the application of a Wigner function description of a two-mode squeezed state, we study a protocol of continuous variable entanglement swapping in a noisy quantum channel. Assuming that the two initial entangled states are coupled with the same environment, we analyse the quantum state emerging from the swapping and obtain the inseparable condition for the output correlation. It is found that there is more noise resulting from the entanglement swapping than from the direct transmission, no matter what values of displacement gain are chosen.

Key words: Continuous variable, entanglement swapping, squeezed state, Wigner function

中图分类号:  (Quantum state engineering and measurements)

  • 42.50.Dv
03.65.Ud (Entanglement and quantum nonlocality) 03.67.Hk (Quantum communication) 42.50.Lc (Quantum fluctuations, quantum noise, and quantum jumps)