Improvement in Superconducting Resonator Quality Factor Through Surface Passivation

ORAL

Abstract

High quality factor resonators are crucial components in photon detectors as well as many quantum computing architectures. There are two dominant mechanisms of loss in these devices. The first is due to two-level systems which mostly reside in the surface oxides. The second stems from a modification of the surface resistance due to quasiparticles within the superconductor. In this study, we characterize the effect of these loss mechanisms for Nb co-planar resonators with and without a TiN capping layer by correlating materials analysis (XPS,TEM) and low temperature electrical measurements. We find that the presence of the capping layer improves the quality factor relative to the standard resonator.

*This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division under Contract No. DE-AC02-05-CH11231 within the QISLBNL program.

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Presenters

  • Cassidy Berk

    • Lawrence Berkeley National Laboratory

Authors

  • Cassidy Berk

    • Lawrence Berkeley National Laboratory

  • Archan Banerjee

    • Lawrence Berkeley National Laboratory
    • University of California, Berkeley

  • AHMED HAJR

    • Lawrence Berkeley National Laboratory

  • John Mark Kreikebaum

    • Lawrence Berkeley National Laboratory
    • University of California, Berkeley
    • Univ of California – Berkeley
    • Physics, University of California, Berkeley

  • Virginia Altoe

    • Lawrence Berkeley National Laboratory

  • David Ivan Santiago

    • Lawrence Berkeley National Laboratory
    • University of California, Berkeley
    • Lawrence Berkely National Laboratory
    • Quantum Nanoelectronics Laboratory, Dept. of Physics, University of California, Berkeley

  • D. Frank Ogletree

    • Lawrence Berkeley National Laboratory

  • Irfan Siddiqi

    • Lawrence Berkeley National Laboratory
    • University of California, Berkeley
    • Univ of California - Berkeley
    • Univ of California – Berkeley
    • Quantum Nanoelectronics Lab, UC Berkeley
    • Physics, University of California, Berkeley
    • Quantum Nanoelectronics Laboratory, Dept. of Physics, University of California, Berkeley