Lifetime of the superconductive state in long Josephson junctions in presence of non-Gaussian noise sources

Abstract

The effects of Lévy noise sources on the transient dynamics of long Josephson junctions (LJJ) are investigated in the presence of both a periodical current signal and a noise source with Gaussian, Cauchy-Lorentz or Levy-Smirnov probability distributions. In particular, by numerically integrating the Sine-Gordon equation, the mean escape time (MET) from the superconductive metastable state is obtained as a function both of the frequency of the periodical force and amplitude of the noise signal. We find resonant activation (RA) and noise enhanced stability (NES). Significative changes in RA and NES are observed by using Lévy noise sources with different statistics. MET is also studied as a function of the junction length, both for spatially homogeneous and inhomogeneous bias current distributions. In the latter case an enhanced non-monotonic behavior is observed in the presence of Gaussian noise. Conversely, the non-monotonic behavior results to be significatively reduced or completely absent for different statistics of the noise source.