Improved certification of Bell-operator correlations via optimization

Physical Review A, vol. 114

Abstract

Bell nonlocality is an intrinsic feature of quantum mechanics, which can be detected via the violation of Bell inequalities. It is therefore a fundamental question to certify Bell nonlocality from experimental data. Here we present an optimization framework to detect Bell-operator correlations by exploring flexible mappings between Bell inequalities and Hamiltonians corresponding to the Bell operators. We show that several Hamiltonian models can be mapped to new inequalities with improved classical bounds compared to the original one, enabling a more robust certification of Bell-operator correlations. From the other direction, we investigate the mapping from fixed Bell inequalities to Hamiltonians, aiming to maximize quantum violations while considering experimental imperfections. As a practical application, we experimentally exploit this method in an -like honeycomb-lattice model utilizing over 70 superconducting qubits. The successful application of this technique, together with the combination of the two directions to form an optimization loop, may open new avenues for developing more practical and noise-resilient certification techniques for Bell-operator correlations and enable broader experimental explorations.

Authors 24

1. Weikang Li Aachen

   Leiden University · Tsinghua University

   Affiliation as printed

   Leiden University

   Tsinghua University

   Universiteit Leiden

2. Ke Wang

   Zhejiang University

   Affiliation as printed

   Zhejiang University

3. Shibo Xu

   Zhejiang University

   Affiliation as printed

   Zhejiang University

4. Zhide Lu

   Shanghai Qi Zhi Institute

   Affiliation as printed

   Shanghai Qi Zhi Institute

5. Yaozu Wu

   Zhejiang University

   Affiliation as printed

   Zhejiang University

6. Chuanyu Zhang

   Zhejiang University

   Affiliation as printed

   Zhejiang University

7. Feitong Jin

   Zhejiang University

   Affiliation as printed

   Zhejiang University

8. Xuhao Zhu

   Zhejiang University

   Affiliation as printed

   Zhejiang University

9. Yu Gao

   Zhejiang University

   Affiliation as printed

   Zhejiang University

10. Zhengyi Cui

    Zhejiang University

    Affiliation as printed

    Zhejiang University

11. Aosai Zhang

    Zhejiang University

    Affiliation as printed

    Zhejiang University

12. Yiren Zou

    Zhejiang University

    Affiliation as printed

    Zhejiang University

13. Fanhao Shen

    Zhejiang University

    Affiliation as printed

    Zhejiang University

14. Jiarun Zhong

    Zhejiang University

    Affiliation as printed

    Zhejiang University

15. Zehang Bao

    Zhejiang University

    Affiliation as printed

    Zhejiang University

16. Zitian Zhu

    Zhejiang University

    Affiliation as printed

    Zhejiang University

17. Pengfei Zhang
    Affiliation as printed

    ZJU-Hangzhou Global Scientific and Technological Innovation Center

18. Hekang Li
    Affiliation as printed

    ZJU-Hangzhou Global Scientific and Technological Innovation Center

19. Qiujiang Guo
    Affiliation as printed

    ZJU-Hangzhou Global Scientific and Technological Innovation Center

20. Zhen Wang

    Zhejiang University

    Affiliation as printed

    Hefei National Laboratory

    Zhejiang University

21. Dong‐Ling Deng

    Shanghai Qi Zhi Institute · Tsinghua University

    Affiliation as printed

    Hefei National Laboratory

    Shanghai Qi Zhi Institute

    Tsinghua University

22. Hui-Ting Wang

    Zhejiang University

    Affiliation as printed

    Hefei National Laboratory

    ZJU-Hangzhou Global Scientific and Technological Innovation Center

    Zhejiang University

23. Patrick Emonts Aachen

    Leiden University · Universität Ulm · Center for Integrated Quantum Science and Technology

    Affiliation as printed

    Center for Integrated Quantum Science and Technology

    Leiden University

    Ulm University

    Universiteit Leiden

24. Jordi Tura Aachen

    Leiden University

    Affiliation as printed

    Leiden University

    Universiteit Leiden