Extensible quantum circuit for the surface-code error correction cycle with frequency-tunable transmon qubits

ORAL

Abstract

We propose an extensible scheme for implementing the surface-code error correction cycle with fast-frequency-tuneable transmon qubits in a circuit QED architecture. This solution consists of a spatially repeating unit cell circuit with four data-carrying qubits, four ancillary qubits, four frequencies for single-qubit control, and eight frequency excursions for conditional-phase (C-Z) gates. By pipelining the interaction and ancilla measurement steps of $X$- and $Z$-type stabilizers, we engineer the frequency excursion patterns to avoid transmon-transmon interactions except the $|11\rangle-|02\rangle|$ avoided crossings exploited in C-Z gates. This scheme is amenable to planar and hole-based implementations of the surface code and to lattice surgery. Crucially, it allows the expansion of the surface-code fabric by spatial repetition and maximal exploitation of spatial and frequency multiplexing in the control architecture.

*Funding by FOM, NWO, Intel Corporation and IARPA

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Authors

  • Richard Versluis

    • QuTech and TNO, Delft

  • Stefano Poletto

    • QuTech and Kavli Institute of Nanoscience, Delft University of Technology, The Netherlands

  • Nader Khammassi

    • QuTech, Computer Engineering Lab, Delft University of Technology, The Netherlands

  • Koen Bertels

    • QuTech, Computer Engineering Lab and Kavli Institute of Nanoscience, Delft University of Technology, The Netherlands

  • Leonardo DiCarlo

    • QuTech and Kavli Institute of Nanoscience, TU Delft, The Netherlands
    • QuTech and Kavli Institute of Nanoscience, Delft University of Technology, The Netherlands
    • QuTech and the Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
    • QuTech and Kavli Institute of Nanoscience, Delft University of Technology and Intel Corporation
    • QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
    • QuTech and Kavli Institute of Nanoscience, Delft University of Technology