High-fidelity iToffoli gate for fixed-frequency superconducting qubits

ORAL

Abstract

Several three-qubit gates have been implemented for superconducting qubits, but their use in gate synthesis has been limited due to their low fidelity. Here, using fixed-frequency superconducting qubits, we demonstrate a high-fidelity iToffoli gate based on two-qubit interactions, the so-called cross-resonance effect. As with the Toffoli gate, this three-qubit gate can be used to perform universal quantum computation. The iToffoli gate is implemented by simultaneously applying microwave pulses to a linear chain of three qubits, revealing a process fidelity as high as 98.26(2)%. Moreover, we numerically show that our gate scheme can produce additional three-qubit gates which provide more efficient gate synthesis than the Toffoli and iToffoli gates.

*This work was supported by the Quantum Testbed Program of the Advanced Scientific Computing Research for Basic Energy Sciences program, Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

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Publication: Y. Kim et al., arXiv:2108.10288.

Presenters

  • Yosep Kim

    • Lawrence Berkeley National Laboratory

Authors

  • Yosep Kim

    • Lawrence Berkeley National Laboratory

  • Alexis Morvan

    • Lawrence Berkeley National Laboratory

  • Long B Nguyen

    • Lawrence Berkeley National Laboratory

  • Ravi K Naik

    • University of California, Berkeley
    • Lawrence Berkeley National Laboratory

  • Christian Jünger

    • Lawrence Berkeley National Laboratory
    • University of Basel

  • Larry Chen

    • University of California, Berkeley

  • John Mark Kreikebaum

    • Lawrence Berkeley National Laboratory

  • David I Santiago

    • Lawrence Berkeley National Laboratory
    • Computational Research Division, Lawrence Berkeley National Lab

  • Irfan Siddiqi

    • University of California, Berkeley
    • Applied Mathematics and Computational Research and Materials Sciences Divisions, LBNL
    • Lawrence Berkeley National Laboratory
    • Applied Mathematics, Computational Research and Materials Sciences Divisions, Lawrence Berkeley National Lab