We observe several sharp changes in the slope of the current-voltage characteristics (CVCs) of thin-film ramp-edge Josephson junctions between YBa2Cu3O7−delta and Nb when applying strong microwave fields. Such behavior indicates an intriguing Josephson dynamics associated with the switching from a parametric excitation regime induced by the magnetic field of the microwave via oscillations of the Josephson critical current to an ac-current-excitation regime triggered by the electric field of the microwave. We propose a model, which describes the observed features on the CVC in terms of microwave-induced multiple switching between running and locked solutions of sine-Gordon equation.
|Journal||Physical review B: Condensed matter and materials physics|
|Publication status||Published - 2008|