Fast qubit resetting with a quantum-circuit refrigerator

ORAL

Abstract

Superconducting qubits have emerged as powerful building blocks for a quantum computer. However, precise reset of qubits into their ground states remains a challenge. Although qubits naturally relax, this process is slow for high-coherence qubits and eventually inhibits fast computing. A way forward is provided by a voltage-tunable quantum-circuit refrigerator (QCR), a microcooler based on photon-assisted electron tunneling in a pair of NIS junctions. Here, we present an experimental realization of a QCR coupled to a transmon qubit as well as its optimization for fast on-demand qubit reset.

We evaluate the influence of a QCR on characteristic qubit lifetimes T1 and T2 and present a coupling design that allows for both long qubit lifetime and efficient cooling. Furthermore, we show the effects of pulsed operation of the QCR, which enables a reset of the qubit state in the nanosecond range, considering various noise levels. This device not only improves qubit performance, but offers a versatile platform for studies on open quantum systems.

*This research is supported by the Foundation for Aalto University Science and Technology and the European Research Council under Grant No. 681311 (QUESS). We also thank Quantum Technology Finland (QTF).

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Presenters

  • Timm Mörstedt

    • QCD Labs, Department of Applied Physics, Aalto University

Authors

  • Timm Mörstedt

    • QCD Labs, Department of Applied Physics, Aalto University

  • Giacomo Catto

    • QCD Labs, Department of Applied Physics, Aalto University

  • Arto Viitanen

    • QCD Labs, Department of Applied Physics, Aalto University

  • Tianyi Li

    • IQM Quantum Computers
    • IQM Finland Oy

  • Wei Liu

    • IQM Quantum Computers
    • IQM Finland Oy

  • Joni Ikonen

    • IQM Quantum Computers
    • QCD Labs, Department of Applied Physics, Aalto University
    • IQM
    • IQM Finland Oy

  • Vasilii Sevriuk

    • IQM Quantum Computers
    • IQM Finland Oy

  • Jan Goetz

    • IQM Quantum Computers
    • IQM Finland Oy

  • Máté Jenei

    • IQM Quantum Computers
    • IQM Finland Oy

  • Matti Silveri

    • Nano and Molecular Systems Research Unit, University of Oulu
    • Nano and molecular systems research unit, University of Oulu
    • Nano and molecular systems research unit, Univ of Oulu
    • University of Oulu

  • Matti Partanen

    • QCD Labs, Aalto University
    • Walther-Meißner-Institut, Bavarian Academy of Sciences and Humanities
    • Walther-Meißner-Institut, Technische Universität München
    • Walther-Meißner-Institute, Bavarian Academy of Sciences and Humanities & Physik-Department, Technische Universität München, Germany
    • QCD Labs, Department of Applied Physics, Aalto University

  • Leif Grönberg

    • VTT Micro & Nanoelectronics
    • VTT Techical Research Center of Finland Ltd.
    • VTT Technical Research Centre of Finland Ltd
    • QTF Centre of Excellence, VTT Technical Research Centre of Finland Ltd.

  • Visa Vesterinen

    • VTT
    • VTT Micro & Nanoelectronics
    • VTT Techical Research Center of Finland Ltd.
    • VTT Technical Research Centre of Finland Ltd

  • Gianluigi Catelani

    • JARA Institute for Quantum Information, Forschungszentrum Jülich
    • Forschungszentrum Juelich GmbH
    • Forschungszentrum Julich
    • JARA-Institute Quantum Information (PGI-11), Forschungszentrum Jülich

  • Tapio Ala-Nissila

    • MSP Group, Department of Applied Physics, Aalto University
    • Department of Applied Physics, Aalto University

  • Mikko Möttönen

    • QCD Labs, Aalto University
    • QCD Labs, Department of Applied Physics, Aalto University
    • IQM Finland Oy