Low-Loss Dielectric Materials and the Merged Element Transmon

ORAL

Abstract

Josephson junctions, a crucial component in quantum bits (qubits), are commonly composed of a pair of superconducting aluminum films separated by a thin layer of amorphous aluminum oxide. In order to avoid the high density of two-level states (TLS) in amorphous oxides, Josephson junctions are designed to be small, thus reducing the participation of the lossy material. However, the persistence of lossy materials in qubits leads to diminishing returns with this strategy. An alternative approach to TLS loss minimization in a transmon qubit junction is to combine the qubit’s nonlinear inductance and capacitance into a single trilayer junction with extremely low dielectric loss, i.e., a merged-element transmon. In this work, we characterize dielectric thin films within lumped-element resonators to determine microwave losses in the single-photon regime and to identify dielectric barrier materials for a merged element transmon. In addition to amorphous solid barriers, we measure microwave-frequency loss of single-crystal epitaxial superconductor-insulator-superconductor trilayers.

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Presenters

  • Corey Rae McRae

    National Institute of Standards and Technology Boulder, National Institute of Standards and Technology, Boulder

Authors

  • Corey Rae McRae

    National Institute of Standards and Technology Boulder, National Institute of Standards and Technology, Boulder

  • Anthony McFadden

    University of California, Santa Barbara, ECE and Materials, University of California, Santa Barbara, University of California Santa Barbara

  • Mustafa Bal

    National Institute of Standards and Technology Boulder

  • Xian Wu

    Physical and Life Sciences Directorate, Lwarence Livermore National Laboratory, National Institute of Standards and Technology, Boulder, National Institute of Standards and Technology Boulder, Lawrence Livermore National Laboratory

  • Junling Long

    National Institute of Standards and Technology Boulder, National Institute of Standards and Technology, Boulder

  • Hsiang-Sheng Ku

    National Institute of Standards and Technology Boulder, National Institute of Standards and Technology, Boulder, Alibaba

  • Jianguo Wen

    Center for Nanoscale Materials, Argonne National Laboratory, Argonne National Laboratory

  • Jie Wang

    Center for Nanoscale Materials, Argonne National Laboratory, Argonne National Laboratory

  • Ilke Arslan

    Center for Nanoscale Materials, Argonne National Laboratory, Argonne National Laboratory

  • Chris Palmstrom

    University of California, Santa Barbara, University of California - Santa Barbara, University of California Santa Barbara, Electrical & Computer Engineering, University of California, Santa Barbara, ECE and Materials, University of California, Santa Barbara, Dept. of ECE, University of California Santa Barbara, Materials Department, University of California, Santa Barbara, Materials Engineering, University of California, Santa Barbara, University of California Santa Barbara, Materials Engineering, Departments of Electrical and Computer Engineering and Materials, University of California, Santa Barbara

  • David Pappas

    National Institute of Standards and Technology (NIST), Boulder, Quantum Devices, NIST-Boulder, National Institute of Standards and Technology Boulder, NIST, Boulder, Colorado, National Institute of Standards and Technology, Boulder

  • Russell Lake

    National Institute of Standards and Technology (NIST), Boulder, Boulder, NIST, National Institute of Standards and Technology Boulder, National Institute of Standards and Technology, Boulder