中国物理B ›› 2019, Vol. 28 ›› Issue (4): 44203-044203.doi: 10.1088/1674-1056/28/4/044203

• ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS • 上一篇    下一篇

Quantum interferometry via a coherent state mixed with a squeezed number state

Li-Li Hou(侯丽丽), Yong-Xing Sui(眭永兴), Shuai Wang(王帅), Xue-Fen Xu(许雪芬)   

  1. 1 School of Mathematics and Physics, Jiangsu University of Technology, Changzhou 213001, China;
    2 Department of Fundamental Courses, Wuxi Institute of Technology, Wuxi 214121, China
  • 收稿日期:2018-12-13 修回日期:2019-01-15 出版日期:2019-04-05 发布日期:2019-04-05
  • 通讯作者: Shuai Wang, Xue-Fen Xu E-mail:ruifeng.wshslxy@jsut.edu.cn;xuxf@wxit.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 11404040) and the Qing Lan Project of the Higher Educations of Jiangsu Province of China.

Quantum interferometry via a coherent state mixed with a squeezed number state

Li-Li Hou(侯丽丽)1, Yong-Xing Sui(眭永兴)1, Shuai Wang(王帅)1, Xue-Fen Xu(许雪芬)2   

  1. 1 School of Mathematics and Physics, Jiangsu University of Technology, Changzhou 213001, China;
    2 Department of Fundamental Courses, Wuxi Institute of Technology, Wuxi 214121, China
  • Received:2018-12-13 Revised:2019-01-15 Online:2019-04-05 Published:2019-04-05
  • Contact: Shuai Wang, Xue-Fen Xu E-mail:ruifeng.wshslxy@jsut.edu.cn;xuxf@wxit.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 11404040) and the Qing Lan Project of the Higher Educations of Jiangsu Province of China.

摘要:

We theoretically investigate the phase sensitivity with parity measurement on a Mach-Zehnder interferometer with a coherent state combined with a squeezed number state. Within a constraint on the total mean photon number, we find, via parity measurement, that the mixing of a coherent state and squeezed number state can give better phase sensitivity than mixing a coherent state and squeezed vacuum state when the phase shift deviates from the optimal phase φ=0. In addition, we show that the classical Fisher information for parity measurement saturates the quantum Fisher information when the phase shift approaches to zero. Thus, the quantum Cramér-Rao bound can be reached via the parity measurement in the case of φ=0.

关键词: quantum optics, phase sensitivity, quantum metrology

Abstract:

We theoretically investigate the phase sensitivity with parity measurement on a Mach-Zehnder interferometer with a coherent state combined with a squeezed number state. Within a constraint on the total mean photon number, we find, via parity measurement, that the mixing of a coherent state and squeezed number state can give better phase sensitivity than mixing a coherent state and squeezed vacuum state when the phase shift deviates from the optimal phase φ=0. In addition, we show that the classical Fisher information for parity measurement saturates the quantum Fisher information when the phase shift approaches to zero. Thus, the quantum Cramér-Rao bound can be reached via the parity measurement in the case of φ=0.

Key words: quantum optics, phase sensitivity, quantum metrology

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

  • 42.50.Dv
03.65.Ta (Foundations of quantum mechanics; measurement theory)