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Epitaxial GaAs Loss Measurements and the Merged Element Transmon

ORAL

Abstract

Transmon qubits are traditionally composed of two components: a Josephson junction, which is commonly made up of a pair of superconducting aluminum films separated by a thin layer of amorphous aluminum oxide, and a large paddle capacitor. The presence of lossy materials in this design, as well as the significant size of the capacitor paddles, limits the transmon’s performance and scalability. In contrast, the merged element transmon design combines the qubit's nonlinear inductance and capacitance into a single trilayer junction with extremely low dielectric loss. GaAs is a good candidate test material for these trilayer junctions as its epitaxial growth and interface with Al is well-characterized, and single crystal growth and lattice matching is possible. In this work, we use dielectric loss extraction methods to accurately measure the TLS loss for Al/GaAs/Al trilayers.

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Presenters

  • Corey Rae McRae

    NIST Boulder / CU Boulder, NIST, National Institute of Standard and Technology Boulder, National Institute of Standards and Technology Boulder

Authors

  • Corey Rae McRae

    NIST Boulder / CU Boulder, NIST, National Institute of Standard and Technology Boulder, National Institute of Standards and Technology Boulder

  • Anthony P McFadden

    UCSB, Dept. of Electrical Engineering, Univ. of California, Santa Barbara, CA, USA, University of California, Santa Barbara, Univ of California, Santa Barbara

  • Ruichen Zhao

    NIST Boulder / CU Boulder, National Institute of Standards and Technology Boulder, National Institute of Standard and Technology Boulder, National Institute of Standards and Technology - Boulder

  • Haozhi Wang

    NIST Boulder / CU Boulder, National Institute of Standards and Technology Boulder, National Institute of Standard and Technology Boulder

  • Sungoh Park

    NIST Boulder / CU Boulder, National Institute of Standards and Technology Boulder, University of Colorado, Boulder, University of Colorado Boulder

  • Junling Long

    NIST Boulder / CU Boulder, National Institute of Standards and Technology Boulder, University of Colorado Boulder, Physics, CU Boulder, Physics, University of Colorado-Boulder

  • Chris J Palmstrom

    Materials Department, University of California, Santa Barbara, UCSB, Departments of Electrical and Computer Engineering and Materials, University of California, Santa Barbara, Dept. of Electrical Engineering, Univ. of California, Santa Barbara, CA, USA, Univ. of California, Santa Barbara, Electrical and Computer Engineering Department, University of California, Santa Barbara, University of California, Santa Barbara, IEE, UC Santa Barbara, University of California Santa Barbara, Univ of California, Santa Barbara, Electrical and Computer Engineering, University of California Santa Barbara, Materials and Electrical & Comp. Eng, University of California, Santa Barbara

  • David Pappas

    NIST Boulder, National Institute of Standards and Technology Boulder, NIST, National Institute of Standards and Technology, National Institute of Standard and Technology Boulder, National Institute of Standards and Technology - Boulder