Passage of positively and negatively charged particles through straight and bent nanotubes

Passage of high-energy charged particles through oriented crystals and nanotubes is investigated. It is shown that the particle passage through crystals and nanotubes may to be described in the same manner. The possibility of positively and negatively charged particle deflection by bent nanotube due to axial channelling phenomenon is demonstrated. Computer simulation results for relativistic charged particle beam passage through straight and bent nanotubes are presented

Non-Gaussian noise effects in the dynamics of a short overdamped Josephson junction

The role of thermal and non-Gaussian noise on the dynamics of driven short overdamped Josephson junctions is studied. The mean escape time of the junction is investigated considering Gaussian, Cauchy-Lorentz and L\ue9vy-Smirnov probability distributions of the noise signals. In these conditions we find resonant activation and the first evidence of noise enhanced stability in a metastable system in the presence of L\ue9vy noise. For Cauchy-Lorentz noise source, trapping phenomena and power law dependence on the noise intensity are observed