Tunable refrigerator for nonlinear quantum electric circuits

Physical review. B./Physical review. B, vol. 101

Abstract

The emerging quantum technological applications call for fast and accurate initialization of the corresponding devices to low-entropy quantum states. To this end, we theoretically study a recently demonstrated quantum-circuit refrigerator in the case of nonlinear quantum electric circuits such as superconducting qubits. The maximum refrigeration rate of transmon and flux qubits is observed to be roughly an order of magnitude higher than that of usual linear resonators, increasing flexibility in the design. We find that for typical experimental parameters, the refrigerator is suitable for resetting different qubit types to fidelities above 99.99% in a few or a few tens of nanoseconds depending on the scenario. Thus the refrigerator appears to be a promising tool for quantum technology and for detailed studies of open quantum systems.

Authors 6

1. Hao Hsu Aachen JARA-Institute for Quantum Information

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA Institute for Quantum Information (PGI-11), Forschungszentrum Jülich, 52425 Jülich, Germany

   JARA Institute for Quantum Information, RWTH Aachen University, 52056 Aachen, Germany

2. Matti Silveri

   University of Oulu · Aalto University

   Affiliation as printed

   QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 13500, FI-00076 Aalto, Finland

   Research Unit of Nano and Molecular Systems, University of Oulu, P.O. Box 3000, FI-90014 Oulu, Finland

3. András Gunyhó

   Aalto University

   Affiliation as printed

   QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 13500, FI-00076 Aalto, Finland

4. Jan Goetz

   IQM (Finland) · Aalto University

   Affiliation as printed

   IQM, Keilaranta 19, FI-02150 Espoo, Finland

   QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 13500, FI-00076 Aalto, Finland

5. Gianluigi Catelani

   Forschungszentrum Jülich · Jülich Aachen Research Alliance

   Affiliation as printed

   JARA Institute for Quantum Information (PGI-11), Forschungszentrum Jülich, 52425 Jülich, Germany

6. Mikko Möttönen

   VTT Technical Research Centre of Finland · Aalto University

   Affiliation as printed

   QCD Labs, QTF Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 13500, FI-00076 Aalto, Finland

   VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, FI-02044 VTT, Finland