中国物理B ›› 2022, Vol. 31 ›› Issue (4): 40309-040309.doi: 10.1088/1674-1056/ac4229

• • 上一篇    下一篇

Beating standard quantum limit via two-axis magnetic susceptibility measurement

Zheng-An Wang(王正安)1,2,†, Yi Peng(彭益)1,3,†, Dapeng Yu(俞大鹏)3,4,5, and Heng Fan(范桁)1,2,6,7,‡   

  1. 1 Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China;
    3 Shenzhen Insititute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China;
    4 Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China;
    5 Shenzhen Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China;
    6 CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China;
    7 Songshan Lake Materials Laboratory, Dongguan 523808, China
  • 收稿日期:2021-10-28 修回日期:2021-12-05 接受日期:2021-12-11 出版日期:2022-03-16 发布日期:2022-03-21
  • 通讯作者: Heng Fan E-mail:hfan@iphy.ac.cn
  • 基金资助:
    This work was supported by the National Natural Science Foundation of China (Grant Nos. T2121001, 11934018, and U1801661), Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB28000000), the Key-Area Research and Development Program of GuangDong Province, China (Grant No. 2018B030326001), Guangdong Provincial Key Laboratory (Grant No. 2019B121203002), the Science, Technology and Innovation Commission of Shenzhen Municipality (Grant Nos. KYTDPT20181011104202253 and 2016ZT06D348).

Beating standard quantum limit via two-axis magnetic susceptibility measurement

Zheng-An Wang(王正安)1,2,†, Yi Peng(彭益)1,3,†, Dapeng Yu(俞大鹏)3,4,5, and Heng Fan(范桁)1,2,6,7,‡   

  1. 1 Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China;
    3 Shenzhen Insititute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China;
    4 Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China;
    5 Shenzhen Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China;
    6 CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China;
    7 Songshan Lake Materials Laboratory, Dongguan 523808, China
  • Received:2021-10-28 Revised:2021-12-05 Accepted:2021-12-11 Online:2022-03-16 Published:2022-03-21
  • Contact: Heng Fan E-mail:hfan@iphy.ac.cn
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (Grant Nos. T2121001, 11934018, and U1801661), Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB28000000), the Key-Area Research and Development Program of GuangDong Province, China (Grant No. 2018B030326001), Guangdong Provincial Key Laboratory (Grant No. 2019B121203002), the Science, Technology and Innovation Commission of Shenzhen Municipality (Grant Nos. KYTDPT20181011104202253 and 2016ZT06D348).

摘要: We report a metrology scheme which measures the magnetic susceptibility of an atomic spin ensemble along the $x$ and $z$ directions and produces parameter estimation with precision beating the standard quantum limit. The atomic ensemble is initialized via one-axis spin squeezing with optimized squeezing time and parameter $\phi$ (to be estimated) assumed as uniformly distributed between 0 and $2\pi$ while fixed in each estimation. One estimation of $\phi$ can be produced with every two magnetic susceptibility data measured along the two axes respectively, which has an imprecision scaling $({1.43\pm0.02})/N^{0.687\pm0.003}$ with respect to the number $N$ of the atomic spins. The measurement scheme is easy to implement and is robust against the measurement fluctuation caused by environment noise and measurement defects.

关键词: quantum metrology, spin-squeezing, standard quantum limit, fluctuation

Abstract: We report a metrology scheme which measures the magnetic susceptibility of an atomic spin ensemble along the $x$ and $z$ directions and produces parameter estimation with precision beating the standard quantum limit. The atomic ensemble is initialized via one-axis spin squeezing with optimized squeezing time and parameter $\phi$ (to be estimated) assumed as uniformly distributed between 0 and $2\pi$ while fixed in each estimation. One estimation of $\phi$ can be produced with every two magnetic susceptibility data measured along the two axes respectively, which has an imprecision scaling $({1.43\pm0.02})/N^{0.687\pm0.003}$ with respect to the number $N$ of the atomic spins. The measurement scheme is easy to implement and is robust against the measurement fluctuation caused by environment noise and measurement defects.

Key words: quantum metrology, spin-squeezing, standard quantum limit, fluctuation

中图分类号:  (Quantum information)

  • 03.67.-a
06.20.-f (Metrology) 03.67.Bg (Entanglement production and manipulation)