Scalable method for eliminating residual $ZZ$ interaction between superconducting qubits

ORAL

Abstract

Unwanted $ZZ$ interaction is a quantum-mechanical crosstalk phenomenon which correlates qubit dynamics and is ubiquitous in superconducting qubit system. It adversely affects the quality of quantum operations and can be detrimental in scalable quantum information processing. Here we propose and experimentally demonstrate a practically extensible approach for complete cancellation of residual $ZZ$ interaction between fixed-frequency transmon qubits, which are known for long coherence and simple control. We apply to the intermediate coupler that connects the qubits a weak microwave drive at a properly chosen frequency in order to noninvasively induce ac Stark shift for $ZZ$ cancellation. We verify the cancellation performance by measuring vanishing two-qubit entangling phases and $ZZ$ correlations. In addition, we implement randomized benchmarking experiment to extract the idling gate fidelity which shows good agreement with the coherence limit, demonstrating the effectiveness of $ZZ$ cancellation. Our method allows independent addressability of each qubit-qubit connection, and is applicable to both non-tunable and tunable coupler, promising better compatibility with future large-scale quantum processors.

Publication: PhysRevLett.129.040502(2022)

Presenters

  • Zhongchu Ni

    • Southern University of Science and Techn

Authors

  • Zhongchu Ni

    • Southern University of Science and Techn
  • Sai Li

    • South China Normal University
    • Southern Unversity of Science and Technology
  • Libo Zhang

    • Southern University of Science and Techn
    • Southern University of Science and Technology
  • Ji Chu

    • Southern University of Science and Technology
  • Jingjing Niu

    • Southern University of Science and Techn
  • Tongxing Yan

    • SUSTC
  • Xiuhao Deng

    • Southern University of Science and Technology
    • Southern University of Science and Techn
  • Ling Hu

    • Southern University of Science and Techn
  • Jian Li

    • Southern University of Science and Techn
  • Youpeng Zhong

    • Southern University of Science and Techn
  • Song Liu

    • Southern University of Science and Techn
    • Southern University of Science and Technology
  • Fei Yan

    • Southern University of Science and Techn
    • Southern University of Science and Technology
  • Yuan Xu

    • Southern University of Science and Techn
  • Dapeng Yu

    • SUSTC
    • Southern University of Science and Technology