中国物理B ›› 2005, Vol. 14 ›› Issue (2): 336-342.doi: 10.1088/1009-1963/14/2/020

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Entropy squeezing of the field interacting with a nearly degenerate V-type three-level atom

祝世宁1, 周青春2   

  1. (1)State Key Laboratory of Solid State Microstructure, Nanjing University, Nanjing 210093, China; (2)State Key Laboratory of Solid State Microstructure, Nanjing University, Nanjing 210093, China; Department of Mathematics and Physics, Jiangsu University of Science and Technology, Zhenjiang 212003, China
  • 收稿日期:2004-04-07 修回日期:2004-07-05 出版日期:2005-03-02 发布日期:2005-03-02
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No 90201008).

Entropy squeezing of the field interacting with a nearly degenerate V-type three-level atom

Zhou Qing-Chun (周青春)ab, Zhu Shi-Ning (祝世宁)a   

  1. a State Key Laboratory of Solid State Microstructure, Nanjing University, Nanjing 210093, China; b Department of Mathematics and Physics, Jiangsu University of Science and Technology, Zhenjiang 212003, China
  • Received:2004-04-07 Revised:2004-07-05 Online:2005-03-02 Published:2005-03-02
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No 90201008).

摘要: The position- and momentum-entopic squeezing properties of the optical field in the system of a nearly degenerate three-level atom interacting with a single-mode field are investigated. Calculation results indicate that when the field is initially in the vacuum state, it may lead to squeezing of the position entropy or the momentum entropy of the field if the atom is prepared properly. The effects of initial atomic state and the splitting of the excited levels of the atom on field entropies are discussed in this case. When the initial field is in a coherent state, we find that position-entropy squeezing of the field is present even if the atom is prepared in the ground state. By comparing the variance squeezing and entropy squeezing of the field we confirm that entropy is more sensitive than variance in measuring quantum fluctuations.

关键词: field entropy, V-type three-level atom, squeezed state

Abstract: The position- and momentum-entopic squeezing properties of the optical field in the system of a nearly degenerate three-level atom interacting with a single-mode field are investigated. Calculation results indicate that when the field is initially in the vacuum state, it may lead to squeezing of the position entropy or the momentum entropy of the field if the atom is prepared properly. The effects of initial atomic state and the splitting of the excited levels of the atom on field entropies are discussed in this case. When the initial field is in a coherent state, we find that position-entropy squeezing of the field is present even if the atom is prepared in the ground state. By comparing the variance squeezing and entropy squeezing of the field we confirm that entropy is more sensitive than variance in measuring quantum fluctuations.

Key words: field entropy, V-type three-level atom, squeezed state

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

  • 42.50.Dv
42.50.Lc (Quantum fluctuations, quantum noise, and quantum jumps) 32.80.-t (Photoionization and excitation)