Extracting an Effective Jaynes-Cummings Model for an LC Filtered dc SQUID

ORAL

Abstract

Spectroscopy of an Al/AlOx/Al dc SQUID phase qubit revealed peaks suggestive of dispersive photon shifts in a Jaynes-Cummings model, where the role of the resonator is played by an on-chip rf LC filter. A lumped element analysis of the filter-qubit system reveals qubit and resonator modes at the expected frequencies (330 MHz and 8.7 GHz) but an isolation junction mode at $\sim$100 GHz and qubit-filter coupling that is smaller than observed. As an alternative to the lumped element picture, we examine a transmission line model of the SQUID and the first order correction to the lumped element model. We discuss Jaynes-Cummings approximations to these various models.

–

Authors

  • B.K. Cooper

    University of Maryland

  • R.P. Budoyo

    Joint Quantum Institute and Center for Nanophysics and Advanced Materials, Dept. of Physics, University of Maryland, College Park, MD, University of Maryland

  • V. Zaretskey

    University of Maryland

  • C.J. Ballard

    University of Maryland

  • James Anderson

    University of Maryland, College Park, University of Maryland, University of Maryland, College Park, Maryland

  • C.J. Lobb

    University of Maryland, College Park, University of Maryland

  • F.C. Wellstood

    University of Maryland, College Park, University of Maryland