Photon-Number-Dependent Effective Lamb Shift Induced by a Radio-Frequency Quantum-Circuit Refrigerator

ORAL

Abstract

The Lamb shift, an energy shift arising from the presence of the electromagnetic vacuum, has been observed in various quantum systems and established as the part of the energy shift independent of the environmental photon number. However, typical studies are based on simplistic bosonic models and may be challenged in practical quantum devices. We demonstrate [1] a hybrid bosonic-fermionic environment for a linear-resonator mode and observe that the photon number in the environment can dramatically increase both the dissipation and the effective Lamb shift of the mode. Our observations are quantitatively described by a first-principles model which we develop here also to guide device design for future quantum-technological applications. Importantly, the device demonstrated here can be utilized as a fully rf-operated quantum-circuit refrigerator [2] to quickly reset superconducting qubits or other electric quantum devices of interest.

[1] A. Viitanen et al., arXiv:2008.08268 (2020).
[2] K. Y. Tan et al., Nat. Commun. 8, 15189 (2017); M. Silveri et al., Nat. Phys. 15, 533 (2019).

*This research was financially supported by the European Research Council under grant no. 681311 (QUESS) and by the Academy of Finland under its QTF Centre of Excellence grant nos. 312300 and 312059.

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Presenters

  • Mikko Mottonen

    • QCD Labs, Department of Applied Physics, Aalto University

Authors

  • Mikko Mottonen

    • QCD Labs, Department of Applied Physics, Aalto University

  • Arto Viitanen

    • QCD Labs, Department of Applied Physics, Aalto University

  • 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

  • Máté Jenei

    • IQM Quantum Computers
    • IQM Finland Oy

  • Vasilii Sevriuk

    • IQM Quantum Computers
    • IQM Finland Oy

  • Kuan Yen Tan

    • QCD Labs, Aalto University
    • IQM Quantum Computers
    • Quantum Engineer, IQM Finland Oy
    • IQM Finland Oy

  • 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

  • Jan Goetz

    • IQM Quantum Computers
    • IQM Finland Oy

  • 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.

  • Valtteri Lahtinen

    • QCD Labs, Department of Applied Physics, Aalto University