中国物理B ›› 2021, Vol. 30 ›› Issue (4): 44212-.doi: 10.1088/1674-1056/abf03a

所属专题: SPECIAL TOPIC — Quantum computation and quantum simulation

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  • 收稿日期:2020-12-29 修回日期:2021-02-04 接受日期:2021-03-19 出版日期:2021-03-16 发布日期:2021-04-02

Realization of adiabatic and diabatic CZ gates in superconducting qubits coupled with a tunable coupler

Huikai Xu(徐晖凯)1,†, Weiyang Liu(刘伟洋)2,†, Zhiyuan Li(李志远)1, Jiaxiu Han(韩佳秀)1, Jingning Zhang(张静宁)1, Kehuan Linghu(令狐克寰)1, Yongchao Li(李永超)1, Mo Chen(陈墨)1, Zhen Yang(杨真)1, Junhua Wang(王骏华)1, Teng Ma(马腾)1, Guangming Xue(薛光明)1,‡, Yirong Jin(金贻荣)1,¶, and Haifeng Yu(于海峰)1   

  1. 1 Beijing Academy of Quantum Information Sciences, Beijing 100193, China; 2 Shenzhen Insititute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
  • Received:2020-12-29 Revised:2021-02-04 Accepted:2021-03-19 Online:2021-03-16 Published:2021-04-02
  • Contact: These authors contributed equally. Corresponding author. E-mail: xuegm@baqis.ac.cn §Corresponding author. E-mail: jinyr@baqis.ac.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11890704, 12004042, and 11674376), the Natural Science Foundation of Beijing, China (Grant No. Z190012), the National Key Research and Development Program of China (Grant No. 2016YFA0301800), and the Key-Area Research and Development Program of Guang-Dong Province, China (Grant No. 2018B030326001).

Abstract: High fidelity two-qubit gates are fundamental for scaling up the superconducting qubit number. We use two qubits coupled via a frequency-tunable coupler which can adjust the coupling strength, and demonstrate the CZ gate using two different schemes, adiabatic and diabatic methods. The Clifford based randomized benchmarking (RB) method is used to assess and optimize the CZ gate fidelity. The fidelities of adiabatic and diabatic CZ gates are 99.53(8)% and 98.72(2)%, respectively. We also analyze the errors induced by the decoherence. Comparing to 30 ns duration time of adiabatic CZ gate, the duration time of diabatic CZ gate is 19 ns, revealing lower incoherence error rate $r'_{incoherent, int} = 0.0197(5)$ compared to $r_{incoherent, int} = 0.0223(3)$.

Key words: controlled-Z gates, high fidelity gates, tunable coupler

中图分类号:  (Quantum description of interaction of light and matter; related experiments)

  • 42.50.Ct
03.67.Lx (Quantum computation architectures and implementations) 74.50.+r (Tunneling phenomena; Josephson effects) 85.25.Cp (Josephson devices)