中国物理B ›› 2021, Vol. 30 ›› Issue (10): 100309-100309.doi: 10.1088/1674-1056/ac0520

所属专题: SPECIAL TOPIC — Non-Hermitian physics

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Observation of the exceptional point in superconducting qubit with dissipation controlled by parametric modulation

Zhan Wang(王战)1,2, Zhongcheng Xiang(相忠诚)1, Tong Liu(刘桐)1,2, Xiaohui Song(宋小会)1, Pengtao Song(宋鹏涛)1,2, Xueyi Guo(郭学仪)1, Luhong Su(苏鹭红)1,2, He Zhang(张贺)1,2, Yanjing Du(杜燕京)1,4, and Dongning Zheng(郑东宁)1,2,3,†   

  1. 1 Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 University of Chinese Academy of Sciences, Beijing 100049, China;
    3 Songshan Lake Materials Laboratory, Dongguan 523808, China;
    4 China University of Geosciences, Beijing 100083, China
  • 收稿日期:2021-05-07 修回日期:2021-05-22 接受日期:2021-05-26 出版日期:2021-09-17 发布日期:2021-09-26
  • 通讯作者: Dongning Zheng E-mail:dzheng@iphy.ac.cn
  • 基金资助:
    Project supported by the State Key Development Program for Basic Research of China (Grant Nos. 2017YFA0304300 and 2016YFA0300600), the Key-Area Research and Development Program of Guangdong Province, China (Grant No. 2020B0303030001), and the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB28000000).

Observation of the exceptional point in superconducting qubit with dissipation controlled by parametric modulation

Zhan Wang(王战)1,2, Zhongcheng Xiang(相忠诚)1, Tong Liu(刘桐)1,2, Xiaohui Song(宋小会)1, Pengtao Song(宋鹏涛)1,2, Xueyi Guo(郭学仪)1, Luhong Su(苏鹭红)1,2, He Zhang(张贺)1,2, Yanjing Du(杜燕京)1,4, and Dongning Zheng(郑东宁)1,2,3,†   

  1. 1 Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 University of Chinese Academy of Sciences, Beijing 100049, China;
    3 Songshan Lake Materials Laboratory, Dongguan 523808, China;
    4 China University of Geosciences, Beijing 100083, China
  • Received:2021-05-07 Revised:2021-05-22 Accepted:2021-05-26 Online:2021-09-17 Published:2021-09-26
  • Contact: Dongning Zheng E-mail:dzheng@iphy.ac.cn
  • Supported by:
    Project supported by the State Key Development Program for Basic Research of China (Grant Nos. 2017YFA0304300 and 2016YFA0300600), the Key-Area Research and Development Program of Guangdong Province, China (Grant No. 2020B0303030001), and the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB28000000).

摘要: Open physical systems described by the non-Hermitian Hamiltonian with parity-time-reversal (PT) symmetry show peculiar phenomena, such as the presence of an exceptional point (EP) at which the PT symmetry is broken and two resonant modes of the Hamiltonian become degenerate. Near the EP, the system could be more sensitive to external perturbations and this may lead to enhanced sensing. In this paper, we present experimental results on the observation of PT symmetry broken transition and the EP using a tunable superconducting qubit. The quantum system of investigation is formed by the two levels of the qubit and the energy loss of the system to the environment is controlled by a method of parametric modulation of the qubit frequency. This method is simple with no requirements for additional elements or qubit device modifications. We believe it can be easily implemented on multi-qubit devices that would be suitable for further exploration of non-Hermitian physics in more complex and diverse systems.

关键词: exceptional point, parity-time-reversal (PT) symmetry, longitudinal field modulation

Abstract: Open physical systems described by the non-Hermitian Hamiltonian with parity-time-reversal (PT) symmetry show peculiar phenomena, such as the presence of an exceptional point (EP) at which the PT symmetry is broken and two resonant modes of the Hamiltonian become degenerate. Near the EP, the system could be more sensitive to external perturbations and this may lead to enhanced sensing. In this paper, we present experimental results on the observation of PT symmetry broken transition and the EP using a tunable superconducting qubit. The quantum system of investigation is formed by the two levels of the qubit and the energy loss of the system to the environment is controlled by a method of parametric modulation of the qubit frequency. This method is simple with no requirements for additional elements or qubit device modifications. We believe it can be easily implemented on multi-qubit devices that would be suitable for further exploration of non-Hermitian physics in more complex and diverse systems.

Key words: exceptional point, parity-time-reversal (PT) symmetry, longitudinal field modulation

中图分类号:  (Quantum information)

  • 03.67.-a
03.65.Aa (Quantum systems with finite Hilbert space) 03.67.Lx (Quantum computation architectures and implementations) 03.65.Ta (Foundations of quantum mechanics; measurement theory)