Local trimming of transmon qubit frequency by laser annealing of Josephson junctions

ORAL

Abstract

Limited control in the fabrication of Al-AlOx-Al Josephson junctions makes accurate targeting of the qubit transition frequency in superconducting quantum processors an outstanding challenge. We demonstrate a selective increase in junction resistance by localized thermal annealing using a focused diode laser source at room temperature. By tuning the irradiation time and incident laser power, we controllably increase junction resistance by up to 15%. We quantify the success of this targeting method by comparing transmon qubit transition frequencies and coherence before and after laser annealing.

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Presenters

  • Nandini Muthusubramanian

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

Authors

  • Nandini Muthusubramanian

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

  • Alessandro Bruno

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

  • Brian M Tarasinski

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

  • Andreas Fognini

    Kavli Institute of Nanoscience Delft, Delft University of Technology

  • Ronald Hagen

    Department of Optics, Netherlands Organization for Applied Scientific Research (TNO)

  • Leonardo DiCarlo

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