A Superconducting 0-π Qubit Based on High Transmission Semiconductor-Superconductor Josephson Junctions

ORAL

Abstract

The 0-π qubit has been proposed as the fundamental building block of topologically protected qubits [1] that feature topologically protected gates [2]. Recent experiments have measured non-cosinusoidal energy-phase relations in high-transmission, semiconductor-superconductor Josephson junctions (JJ) in gatemon qubits [3,4]. Here we present measurements on a superconducting circuit architecture exploiting this non-cosinusoidal energy-phase relation to form a protected 0-π qubit [5]. Voltage control of the semiconductor JJ’s creates a unique superconducting qubit system allowing in situ tuning between widely different qubit regimes: transmon, flux, and 0-π qubit. Close to the 0-π regime we observe enhanced lifetimes indicating protected qubit states.

[1] B. Douçot and L. B. Ioffe, Rep. Prog. Phys. 75, 072001 (2012).
[2] P. Brooks et al. Phys. Rev. A 87, 052306 (2013).
[3] G. de Lange et al. Phys. Rev. Lett. 115, 127002 (2015).
[4] A. Kringhøj et al. Submitted.
[5] M. T. Bell et al. Phys. Rev. Lett. 112, 167001 (2014).

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Presenters

  • Thorvald Larsen

    Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, University of Copenhagen, Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute

Authors

  • Thorvald Larsen

    Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, University of Copenhagen, Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute

  • Lucas Casparis

    Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, Niels Bohr Institute, Univ of Copenhagen

  • Anders Kringhøj

    Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, Niels Bohr Institute, Univ of Copenhagen

  • Natalie Pearson

    Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Niels Bohr Institute, Univ of Copenhagen

  • Robert McNeil

    Niels Bohr Institute, University of Copenhagen, Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen

  • Ferdinand Kuemmeth

    Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Niels Bohr Institute, Univ of Copenhagen, Univ of Copenhagen

  • Michael Gershenson

    Rutgers Univ, Department of Physics and Astronomy, Rutgers University, Physics, Rutgers

  • Peter Krogstrup

    Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, Center for Quantum Devices and Station-Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, University of Copenhagen

  • Jesper Nygard

    Center for quantum devices, Niels Bohr Institute, Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, Center for Quantum Devices and Station-Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Center of Quantum Devices and Nano-Science Center, Niels Bohr Institute, University of Copenhagen

  • Karl Petersson

    Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, Niels Bohr Institute, Univ of Copenhagen, Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen

  • Charles Marcus

    Center for Quantum Devices and Microsoft Station Q Copenhagen, Niels Bohr Institute, Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, Niels Bohr Institute, Univ of Copenhagen, Univ of Copenhagen, University of Copenhagen