Percolating granular superconductors

Abstract

We investigate diamagnetic fluctuations in percolating granular superconductors. Granular superconductors are known to have a rich phase diagram including normal, superconducting and spin glass phases. Focusing on the normal-superconducting and the normal-spin glass transition at low temperatures, we study he diamagnetic susceptibility ${\chi }^{(1)}$ and the mean square fluctuations of the total magnetic moment ${\chi }^{(2)}$ of large clusters. Our work is based on a random Josephson network model that we analyze with the powerful methods of renormalized field theory. We investigate the structural properties of the Feynman diagrams contributing to the renormalization of ${\chi }^{(1)}$ and ${\chi }^{(2)}$. This allows us to determine the critical behavior of ${\chi }^{(1)}$ and ${\chi }^{(2)}$ to arbitrary order in perturbation theory.

18 pages, 2 figures

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• Conductivity of continuum percolating systems
• Nonlinear random resistor diode networks and fractal dimensions of directed percolation clusters
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• Multifractality in directed percolation
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Cited by in corpus (2)

• Percolation model for the superconductor-insulator transition in granular films
• Corrections to Scaling in Random Resistor Networks and Diluted Continuous Spin Models near the Percolation Threshold