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arXiv · 2101.07746

Tunable Coupling Architecture for Fixed-frequency Transmons

J. Stehlik·D. M. Zajac·D. L. Underwood·T. Phung·J. Blair·S. Carnevale·D. Klaus·G. A. Keefe·A. Carniol·M. Kumph·Matthias Steffen·O. E. Dial
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Abstract

Implementation of high-fidelity two-qubit operations is a key ingredient for scalable quantum error correction. In superconducting qubit architectures tunable buses have been explored as a means to higher fidelity gates. However, these buses introduce new pathways for leakage. Here we present a modified tunable bus architecture appropriate for fixed-frequency qubits in which the adiabaticity restrictions on gate speed are reduced. We characterize this coupler on a range of two-qubit devices achieving a maximum gate fidelity of $99.85\%$. We further show the calibration is stable over one day.

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J. Stehlik, D. M. Zajac, D. L. Underwood, T. Phung, J. Blair, S. Carnevale, D. Klaus, G. A. Keefe, A. Carniol, M. Kumph, Matthias Steffen, O. E. Dial. 2021-01-19. Tunable Coupling Architecture for Fixed-frequency Transmons. https://doi.org/10.1103/physrevlett.127.080505

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