Tunable Dissipator for High-fidelity Cavity and Qubit Initialization

ORAL

Abstract

Superconducting qubit dephasing times are limited by photon shot noise in the proximal readout resonator, due either to stray thermal photons or to coherent photons left over from measurement. At the same time, a small excess population of the qubit 1 state leads to error, and approaches to suppress this error based either on postselection or premeasurement and feedback are unsatisfactory. Here we describe the design and operation of tunable dissipative modes for the fast, deterministic initialization of linear cavities and qubits. We show that the dissipator can be used to provide a fast cavity reset following strong measurement and to suppress photon shot noise dephasing. Sideband gates applied to the qubit-cavity system followed by fast cavity reset are used to achieve high qubit initialization fidelity. We discuss prospects for the integration of tunable dissipators into a scalable multiqubit system.

Presenters

  • FNU Naveen

    • Univ of Wisconsin, Madison

Authors

  • FNU Naveen

    • Univ of Wisconsin, Madison
  • Alexander Opremcak

    • Univ of Wisconsin, Madison
    • Physics, University of Wisconsin Madison
    • University of Wisconsin-Madison
  • Bradley Christensen

    • Univ of Wisconsin, Madison
  • Chris Wilen

    • Physics, University of Wisconsin - Madison
    • Univ of Wisconsin, Madison
  • Ivan Pechenezhskiy

    • Univ of Wisconsin, Madison
    • University of Maryland
    • University of Maryland, College Park
    • Physics, University of Wisconsin Madison
  • JJ Nelson

    • Syracuse Univ
    • Physics, Syracuse Univ
    • Syracuse University
    • Physics, Syracuse University
  • Clement Wong

    • Laboratory for Physical Science
  • Maxim Vavilov

    • Physics, University of Wisconsin-Madison
    • Department of Physics, University of Wisconsin-Madison
    • Univ of Wisconsin, Madison
    • University of Wisconsin-Madison
    • Physics, University of Wisconsin Madison
  • Britton Plourde

    • Syracuse Univ
    • Physics, Syracuse Univ
    • Syracuse University
    • Physics, Syracuse University
  • Robert McDermott

    • Univ of Wisconsin, Madison
    • Physics, University of Wisconsin - Madison
    • Physics, University of Wisconsin-Madison
    • Physics, Univ of Wisconsin-Madison
    • Physics, University of Wisconsin Madison
    • University of Wisconsin-Madison