Spectator and stray errors in surface-code Hamiltonian

ORAL

Abstract

The recent Lattice Hamiltonian (LH) framework in circuit QED has opened new opportunities for accurately modeling large-scale superconducting circuits with many qubits—an essential step toward scalable quantum processors. By enabling the inclusion of many-body interactions among qubits, this approach provides a powerful means to extract a complete and quantitative circuit Hamiltonian, mapping all relevant couplings. I will discuss the impact of stray couplings and spectator errors, and why understanding them is crucial for next-generation quantum hardware design.

*This research received funding from the Horizon Europe OpenSuperQPlus100 project (Grant Agreement No. 101113946).

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Publication: Xuexin Xu, Kuljeet Kaur, Chloé Vignes, Mohammad H. Ansari, John M. Martinis, "Surface-Code Hardware Hamiltonian", DOI: https://arxiv.org/pdf/2507.06201

X. Xu, Manabputra, C. Vignes, M. H. Ansari, John M. Martinis, "Lattice hamiltonians and stray interactions within quantum processors," Physical Review Applied 22, 064030 (2024). DOI: https://doi.org/10.1103/PhysRevApplied.22.064030

X. Xu and M. H. Ansari, zz freedom in two-qubit gates, Physical Review Applied 15, 064074 (2021). https://doi.org/10.1103/PhysRevApplied.15.064074

X. Xu and M. Ansari, Parasitic-free gate: An error protected cross-resonance switch in weakly tunable ar-
chitectures, Physical Review Applied 19, 024057 (2023). DOI: https://doi.org/10.1103/PhysRevApplied.19.024057

J. Ku, X. Xu, M. Brink, D. C. McKay, J. B. Hertzberg, M. H. Ansari, and B. L. T. Plourde, Suppression of unwanted zz interactions in a hybrid two-qubit system, Physical Review Letters 125, 200504 (2020). DOI: https://doi.org/10.1103/PhysRevLett.125.200504

Presenters

  • Mohammad H Ansari

    • Forschungszentrum Jülich GmbH
    • FZ Juelich

Authors

  • Mohammad H Ansari

    • Forschungszentrum Jülich GmbH
    • FZ Juelich

  • John M Martinis

    • University of California, Santa Barbara
    • Qolab

  • Chloé Vignes

    • MIT

  • Xuexin Xu

    • Forschungszentrum Juelich GmbH