Experimental study of flux noise in nanowire transmons subject to an applied magnetic field

ORAL

Abstract

Flux noise is generally the dominant dephasing mechanism in transmon qubits using SQUID loops as a tunable inductive element. Continuing experimental research ambitions to elucidate the microscopic origin and mitigation of flux noise. In this work, we experimentally investigate flux noise using an unconventional knob for circuit QED: an applied magnetic field. We first present various changes introduced to our circuit QED system to further extend the field compatibility of resonators and nanowire transmons beyond 70 mT. Next, we use standard coherence measurements and sensitivity analysis on and off flux sweetspots to investigate the dependence of flux noise on field applied along the axis of the two constituent nanowire junctions.

*Research funded by the ERC Synergy Grant QC-lab, Microsoft Corporation, and the Danish National Research Foundation.

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Presenters

  • Thijs Stavenga

    • Delft University of Technology

Authors

  • Thijs Stavenga

    • Delft University of Technology

  • Florian Luthi

    • Intel Corporation

  • Elmore Vaal

    • Delft University of Technology

  • Oluwatumininu Aluko

    • Delft University of Technology

  • Peter Krogstrup

    • Niels Bohr Institute, University of Copenhagen
    • University of Copenhagen
    • Center for Quantum Devices and Microsoft Quantum Lab--Copenhagen, Niels Bohr Institute, University of Copenhagen
    • Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen

  • Leonardo DiCarlo

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