Phase Purcell Effect and the Crossover to Strong Coupling in Dispersive Circuit QED

ORAL

Abstract

We study the decoherence of a superconducting qubit due to the dispersive coupling to a damped harmonic oscillator. We go beyond the weak qubit-oscillator coupling, which we associate with a {\it phase Purcell effect}, and enter into an unexplored decoherence regime, solving a theoretical inconsistency in existing models: the divergence of the qubit dephasing rate in the absence of environment. Our results can be applied, with small adaptations, to a large variety of other physical systems, e.g. trapped ions and cavity QED, boosting theoretical and experimental decoherence studies.

*Supported by NSERC, DFG SFB 631, EU project EuroSQIP and Elitenetzwerk Bayern.

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Authors

  • Ioana Serban

    • IQC and Physics Department, University of Waterloo and Ludwig-Maximilians-University, Munich
    • Institute for Quantum Computing, Waterloo, Canada and Ludwig-Maximilians-Universitaet Munich, Germany

  • Enrique Solano

    • Department of Physics, Arnold Sommerfeld Center for Theoretical Physics, and Center for NanoScience, Ludwig-Maximilians University Munich, Germany
    • Ludwig-Maximilians-Universitaet, Munich, Germany

  • Frank Wilhelm

    • IQC and Physics Department, University of Waterloo
    • IQC and Physics Department, University of Waterloo, 200 University Ave W, Waterloo, ON, N2L 3G1, Canada
    • Institute for Quantum Computing, University of Waterloo, Ontario, Canada
    • Institute for Quantum Computing, Waterloo, Canada
    • University of Waterloo