Autonomous error correction of a single logical qubit using two transmons

Ziqian Li; Tanay Roy; David Rodríguez Pérez; Kan-Heng Lee; Eliot Kapit; David I Schuster

doi:10.1038/s41467-024-45858-z

Autonomous error correction of a single logical qubit using two transmons

Nat Commun. 2024 Feb 23;15(1):1681. doi: 10.1038/s41467-024-45858-z.

Authors

Ziqian Li^#^{1

2

3}, Tanay Roy^#^{1

2}, David Rodríguez Pérez⁴, Kan-Heng Lee^{1

2}, Eliot Kapit⁴, David I Schuster^{5

6

7

8}

Affiliations

¹ James Franck Institute, University of Chicago, Chicago, IL, 60637, USA.
² Department of Physics, University of Chicago, Chicago, IL, 60637, USA.
³ Department of Applied Physics, Stanford University, Stanford, CA, 94305, USA.
⁴ Department of Physics, Colorado School of Mines, Golden, CO, 80401, USA.
⁵ James Franck Institute, University of Chicago, Chicago, IL, 60637, USA. dschus@stanford.edu.
⁶ Department of Physics, University of Chicago, Chicago, IL, 60637, USA. dschus@stanford.edu.
⁷ Department of Applied Physics, Stanford University, Stanford, CA, 94305, USA. dschus@stanford.edu.
⁸ Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, 60637, USA. dschus@stanford.edu.

^# Contributed equally.

Abstract

Large-scale quantum computers will inevitably need quantum error correction to protect information against decoherence. Traditional error correction typically requires many qubits, along with high-efficiency error syndrome measurement and real-time feedback. Autonomous quantum error correction instead uses steady-state bath engineering to perform the correction in a hardware-efficient manner. In this work, we develop a new autonomous quantum error correction scheme that actively corrects single-photon loss and passively suppresses low-frequency dephasing, and we demonstrate an important experimental step towards its full implementation with transmons. Compared to uncorrected encoding, improvements are experimentally witnessed for the logical zero, one, and superposition states. Our results show the potential of implementing hardware-efficient autonomous quantum error correction to enhance the reliability of a transmon-based quantum information processor.

Abstract

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