Characterizing and reducing microfabrication-induced loss in superconducting devices, Part II: Xmon qubits

ORAL

Abstract

Microfabrication-induced loss has previously been shown to limit the coherence times of both planar and 3-D superconducting qubits. Energy loss in these qubits arises from interactions with two-level state defects which are located in thin lossy surface dielectrics. More recently, we have identified a major source of this loss and then substantially improved this decoherence channel using a novel resonator structure for characterization and improvement. I will report on recent measurements of Xmon qubits with substantially improved coherence times due to our new fabrication process.

Authors

  • Anthony Megrant

    • Google, Santa Barbara
  • A. Dunsworth

    • UC Santa Barbara
  • C. Quintana

    • UC Santa Barbara
  • J. Kelly

    • Google, Santa Barbara
  • R. Barends

    • Google, Santa Barbara
  • B. Campbell

    • UC Santa Barbara
  • Y. Chen

    • Google, Santa Barbara
  • Z. Chen

    • UC Santa Barbara
  • B. Chiaro

    • UC Santa Barbara
  • A. Fowler

    • Google, Santa Barbara
  • E. Jeffrey

    • Google, Santa Barbara
  • J. Mutus

    • Google, Santa Barbara
  • C. Neill

    • UC Santa Barbara
  • P.J.J. O'Malley

    • UC Santa Barbara
  • P. Roushan

    • Google, Santa Barbara
  • D. Sank

    • Google, Santa Barbara
  • A. Vainsencher

    • UC Santa Barbara
  • J. Wenner

    • UC Santa Barbara
  • T. White

    • Google, Santa Barbara
  • J.M. Martinis

    • University of California and Google, Santa Barbara