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arXiv 2303.01427quant-ph
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基于多导数脉冲整形的Cross-Resonance门实验误差抑制

Experimental error suppression in Cross-Resonance gates via multi-derivative pulse shaping

Boxi Li, Tommaso Calarco, Felix Motzoi

AI总结:

针对多比特固定频率超导量子芯片门误差率高、校准难的问题,提出多导数多约束脉冲整形方法,同时抑制多类误差,在IBM公开量子比特上实现99.7(1)%的CNOT保真度,较默认方案提升2-4倍。

摘要:

尽管量子电路的比特数已达到数百比特的可观规模,但其电路深度却未能同步提升。特别是多比特固定频率超导芯片上的云计算门,误差率仍徘徊在1%左右,这与经过精心设计的两比特芯片上取得的进展形成对比——后者的误差率已被推至0.1%水平。尽管存在强大的推动力和大量研究,在这些多比特器件上实现误差抑制的实验演示仍具挑战,主要原因在于量子比特参数分布广泛,且先进控制方法所需的校准过程要求严苛。本文中,我们采用一种基于多导数、多约束脉冲整形的简单控制方法实现了这一目标,该方法可同时应对多种误差源。我们的方法在默认校准方案的基础上实现了2至4倍的性能提升,这一结果在IBM Quantum平台的四个量子比特上得到验证(访问权限有限且为间歇性访问),使得这些大规模固定频率系统能够充分利用其优异的相干时间。在这些公开可用的量子比特上,所实现的CNOT门保真度达到99.7(1)%,这一成果源于相干控制误差抑制和门时间缩短的共同作用。

英文摘要:

While quantum circuits are reaching impressive widths in the hundreds of qubits, their depths have not been able to keep pace. In particular, cloud computing gates on multi-qubit, fixed-frequency superconducting chips continue to hover around the 1% error range, contrasting with the progress seen on carefully designed two-qubit chips, where error rates have been pushed towards 0.1%. Despite the strong impetus and a plethora of research, experimental demonstration of error suppression on these multi-qubit devices remains challenging, primarily due to the wide distribution of qubit parameters and the demanding calibration process required for advanced control methods. Here, we achieve this goal, using a simple control method based on multi-derivative, multi-constraint pulse shaping, which acts simultaneously against multiple error sources. Our approach establishes a two to fourfold improvement on the default calibration scheme, demonstrated on four qubits on the IBM Quantum Platform with limited and intermittent access, enabling these large-scale fixed-frequency systems to fully take advantage of their superior coherence times. The achieved CNOT fidelities of 99.7(1)% on those publically available qubits come from both coherent control error suppression and accelerated gate time.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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