RF critical current of Josephson junction

ORAL

Abstract

The Josephson junction is the only radio-frequency electrical element which can be both non-dissipative and non-linear at low temperatures. While the stability of the junction dynamics in presence of a DC drive has been extensively studied, the microwave drive case is relatively poorly understood, at least experimentally. It is explored by driving an increasing AC current through a Josephson junction which is effectively biased by an AC voltage generator in series with a finite linear imbedding impedance $Z\left( \omega \right)$. For small signal amplitude, the junction behaves as a linear inductor. For higher signal amplitudes, we show that there exists a critical current $I_{c}^{RF}$ beyond which the dynamics of the junction changes qualitatively as a result of its non-linear characteristic. This AC critical current depends strongly on the biasing impedance. We provide a detailed stability diagram from experimental measurements and show that it obeys the simple theory of nonlinear resonance.

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Authors

  • Vladimir Manucharyan

    • Department of Applied Physics, Yale University, New Haven, CT, 06511
    • Department of Applied Physics, Yale University

  • Etienne Boaknin

  • Michael Metcalfe

  • Rajamani Vijayaraghavan

    • Department of Applied Physics, Yale University
    • Yale University

  • I. Siddiqi

    • Department of Applied Physics, Yale University; Department of Physics, University of California, Berkeley
    • Department of Applied Physics, Yale University, Department of Physics, University of California, Berkeley

  • Andreas Wallraff

  • R.J. Schoelkopf

  • Michel Devoret

    • Department of Applied Physics, Yale University, New Haven, CT, 06511
    • Department of Applied Physics, Yale University