A Fluxonium Architecture for QEC, Part 2: Extensible and Spectator-Error-Free Two-Qubit Gate Scheme

ORAL

Abstract

Fault-tolerant quantum computing remains a central goal of the superconducting qubit community, with fluxonium qubits showing significant promise due to their extended coherence times [1] and recent demonstrations of high-fidelity single-qubit [2] and two-qubit gates [3]. Despite this progress, two major challenges must be addressed before fluxonium qubits can be widely adopted for quantum error correction (QEC) applications: the development of fast, high-fidelity, quantum non-demolition measurements and the demonstration of an extensible two-qubit gate scheme resilient to spectator errors.

In this talk, we present an extensible scheme for two-qubit gates in fluxonium qubits. Recent work has focused on microwave-activated conditional-phase (MAP) gates, utilizing a transmon coupler to achieve fast gates while suppressing residual (ZZ) couplings. However, such schemes often suffer from spectator-qubit errors, making them impractical for large qubit arrays. Furthermore, the relatively large charging energy of the fluxonium makes it challenging to support multiple connections. We present a gate scheme that addresses these issues in the presence of nearest-neighbor connectivity. Given the strict bounds on correlated error sources required for QEC, we believe that solving these issues highlights the potential of the fluxonium qubit for such applications.

[1] A. Somoroff, et al., PRL, 2023

[2] D. Rower, L. Ding, et al., arXiv:2406.08295, 2024

[3] L. Ding, et al., PRX, 2023

*This research was sponsored in part by IARPA and the Army Research Office, under the Entangled Logical Qubits program, and was accomplished under Cooperative Agreement Number W911NF-23-2-0212; in part by the U.S. Department of Energy, Office of Science, National Quantum Information Science Research Centers, Quantum Systems Accelerator; and in part under Air Force Contract No. FA8702-15-D-0001. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of IARPA, the Army Research Office, or the U.S. Government. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation herein.

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Presenters

  • Jorge F Marques

    • Massachusetts Institute of Technology

Authors

  • Jorge F Marques

    • Massachusetts Institute of Technology

  • Miguel S S. Moreira

    • MIT
    • Massachusetts Institute of Technology

  • Alex A Chapple

    • Universite de Sherbrooke
    • Université de Sherbrooke

  • Othmane Benhayoune Khadraoui

    • Université de Sherbrooke

  • Boris M Varbanov

    • Université de Sherbrooke

  • Alexander McDonald

    • Université de Sherbrooke

  • William P Banner

    • Massachusetts Institute of Technology

  • Gabriel Cutter

    • Massachusetts Institute of Technology

  • Max Hays

    • MIT
    • Massachusetts Institute of Technology (MIT)
    • Massachusetts Institute of Technology

  • Helin Zhang

    • Massachusetts Institute of Technology

  • Konstantin Nesterov

    • Atlantic Quantum

  • Youngkyu Sung

    • Atlantic Quantum

  • Michael Gingras

    • MIT Lincoln Laboratory

  • Jeffrey M Knecht

    • MIT Lincoln Laboratory

  • Bethany M Niedzielski

    • MIT Lincoln Laboratory
    • Lincoln Laboratory, Massachusetts Institute of Technology

  • Hannah M Stickler

    • MIT Lincoln Laboratory

  • Mollie E Schwartz

    • MIT Lincoln Laboratory
    • Lincoln Laboratory, Massachusetts Institute of Technology

  • Alexandre Blais

    • Université de Sherbrooke

  • Kyle Serniak

    • MIT Lincoln Laboratory
    • Lincoln Laboratory, Massachusetts Institute of Technology

  • Jeffrey A Grover

    • Massachusetts Institute of Technology (MIT)
    • Massachusetts Institute of Technology
    • MIT

  • William D Oliver

    • Massachusetts Institute of Technology
    • Massachusetts Institute of Technology (MIT)