Optimized Shielding and Fabrication Techniques for TiN and Al Microwave Resonators

ORAL

Abstract

We present a systematic study of the effects of shielding and packaging on the internal quality factor (Q$_{\mathrm{i}})$ of Al and TiN microwave resonators designed for use in qubit readout. Surprisingly, Q$_{\mathrm{i}}$ $=$1.3x10$^{\mathrm{6\thinspace }}$TiN samples investigated at 100 mK exhibited no significant changes in linewidth when operated without magnetic shielding and in an open cryo-package. In contrast, Al resonators showed systematic improvement in Q$_{\mathrm{i}}$ with each successive shield. Measurements were performed in an adiabatic demagnetization refrigerator, where typical ambient fields of 0.2 mT are present at the sample stage. We discuss the effect of 100 mK and 500 mK Cu radiation shields and cryoperm magnetic shielding on resonator Q as a function of temperature and input power in samples prepared with a variety of surface treatments, fabrication recipes, and embedding circuits.

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Authors

  • John Mark Kreikebaum

    Univ of California - Berkeley, Quantum Nanoelectronics Laboratory, UC Berkeley

  • Eunseong Kim

    Center for Supersolid & Quantum Matter Research and Department of Physics, KAIST, Daejeon, 305-701, Republic of Korea, Univ of California - Berkeley

  • William Livingston

    Univ of California - Berkeley, Quantum Nanoelectronics Laboratory, UC Berkeley

  • Allison Dove

    Univ of California - Berkeley, Quantum Nanoelectronics Laboratory, UC Berkeley

  • Gregory Calusine

    MIT Lincoln Laboratory

  • D. Hover

    MIT Lincoln Laboratory

  • Danna Rosenberg

    MIT Lincoln Laboratory

  • William Oliver

    MIT Lincoln Laboratory; Research Laboratory of Electronics, Massachusetts Institute of Technology, MIT Lincoln Laboratory; Research Laboratory of Electronics, MIT, Massachusetts Institute of Technology, Lincoln Laboratory, MIT Lincoln Laboratory

  • Irfan Siddiqi

    Quantum Nanoelectronics Laboratory, UC Berkeley, Univ of California - Berkeley, Department of Physics, UC Berkeley, University of California, Berkeley, Quantum Nanoelectronics Laboratory, UC Berkeley; Materials Sciences Division, Lawrence Berkeley National Laboratory, Quantum Nanoelectronics Laboratory, University of California, Berkeley