Radiation and the I?V characteristic of small Josephson junctions

Alexander N. Lykov, I. A. Lykov

Vladimir Bubanja, Alec Maassen van den Brink, D. V. Averin +1 more

D. N. Langenberg, William H. Parker, Barry N. Taylor

Matteo Cirillo, I. Modena, P. Carelli +1 more

A small-area Josephson tunnel junction is pumped by the radiation emitted by a long Josephson junction dc biased on a zero-field singularity. Josephson constant voltage steps are observed in the current-voltage characteristic of the small junction at voltages of ±150 μV corresponding to the fundamental frequency of emission of the oscillator. The radiation also gives rise to quasiparticle steps around the gap-sum voltage of the small junction. From the measured current amplitude of the steps we estimate that the maximum power coupled to the small junction is about 90 nW.

Thilo Bauch, Edoardo Trabaldo, Floriana Lombardi

I. S. Abal’osheva, Piotr Gierłowski, Jaworski, M. +1 more

Preliminary results are presented concerning static properties of a small Josephson junction under the influence of strong microwave radiation. We discuss the correspondence between a Brownian particle moving in a periodic potential and superconducting phase difference in a small Josephson junction. Next, we describe an experimental method of determining the amplitude of microwave current flowing across the junction. Typical examples of static characteristics of the junction are presented, including its dynamical resistance as a function of microwave power. We discuss also the influence of an external magnetic field on the junction dynamics and show that in this case the one-dimensional Stewart-McCumber model becomes insufficient.