Resistive transition in granular disordered high-T${}_c$ superconductors: a numerical study

Abstract

The resistive transition of granular high-T${}_c$ superconductors, characterized by either weak (YBCO-like) or strong (MgB${}_2$-like) links, occurs through a series of avalanche-type current density rearrangements. These rearrangements correspond to the creation of resistive layers, crossing the whole specimen approximately orthogonal to the current density direction, due to the simultaneous transition of a large number of weak-links or grains. The present work shows that exact solution of the Kirchhoff equations for strongly and weakly linked networks of nonlinear resistors, with Josephson junction characteristics, yield the subsequent formation of resistive layers within the superconductive matrix as temperature increases. Furthermore, the voltage noise observed at the transition is related to the resistive layer formation process. The noise intensity is estimated from the superposition of voltage drop elementary events related to the subsequent resistive layers. At the end of the transition, the layers mix-up, the step amplitude decreases and the resistance curve smoothes. This results in the suppression of noise, as experimentally found. Remarkably, a scaling law for the noise intensity with the network size is argued. It allows to extend the results to networks with arbitrary size and, thus, to real specimens.

References in corpus (4)

• Granular Electronic Systems
• Space-Charge-Limited Current Fluctuations in Organic Semiconductors
• Reversible Vortex Ratchet Effects and Ordering in Superconductors with Simple Asymmetric Potential Arrays
• Low frequency random telegraphic noise (RTN) and 1/f noise in the rare-earth manganite Pr${}_{0.63}$Ca${}_{0.37}$MnO${}_3$ near the charge-ordering transition

Cited by in corpus (6)

• The Emerging Energy Web
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• Resistive transition in disordered superconductors with varying intergrain coupling
• Array of Josephson junctions with a non-sinusoidal current-phase relation as a model of the resistive transition of unconventional superconductors
• Noise in resistively shunted Josephson junctions
• Superconducting-insulator transition in disordered Josephson junctions networks