Voltage fluctuations in granular superconductors in the perpendicular configuration

Abstract

The spectral density of voltage fluctuations in granular YBa2Cu3O7−δ superconductors in the perpendicular configuration has been studied in the flux flow mode. It has been found that, in this case, the 1/f-voltage noise observed depends weakly on temperature and is associated with motion of a magnetic flux in the superconductor. A comparison of the data obtained with the results of previous measurements in parallel configuration has shown that voltage noise is produced by a single common source, which is presumably associated with self-organization of the critical state in granular superconductors.

Power-law distribution of the flux avalanches in a Josephson medium

“…Moreover, the behavior of the Josephson medium should exhibit strong fluctuations since the system dynamics is of the avalanche type. Such fluctuations were observed in the experimental study of voltage noise caused by the motion of flux quanta in granular superconductors in different geometries of the experiment [20,21].…”