Josephson-based Threshold Detector for Lévy-Distributed Current Fluctuations

Abstract

We propose a threshold detector for L\'evy distributed fluctuations based on a Josephson junction. The L\'evy noise current added to a linearly ramped bias current results in clear changes in the distribution of switching currents out of the zero-voltage state of the junction. We observe that the analysis of the cumulative distribution function of the switching currents supplies information on both the characteristics shape parameter $\alpha$ of the L\'evy statistics and the intensity of the fluctuations. Moreover, we discuss a theoretical model which allows to extract characteristic features of the L\'evy fluctuations from a measured distribution of switching currents. In view of this results, this system can effectively find an application as a detector for a L\'evy signal embedded in a noisy background.