Magnetic properties of SIS and SNS Josephson junction arrays

Abstract

Josephson junction arrays (JJA) are powerful artificial structures equivalent in many aspects to granular superconducting systems. In this work we show some new and striking results obtained from the magnetic properties of JJA. They associate both Wollheben effect (WE) and vortex avalanche phenomena (VA) to geometrical parameters of shunted and unshunted samples, and to the SIS (superconductor–insulator–superconductor) and SNS (superconductor–normal–superconductor) structures. We also show the size effects on the appearance of the Kosterlitz–Touless (KT) transition observed in SNS samples, determined by the mutual-inductance technique.