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.

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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