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.
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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