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Models for granular superconductivity: The effect of quantum fluctuations

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Abstract

We develop two models for the onset of superconductivity in granular superconductors. The inclusion of a parallel shunt resistor between the grains constitutes the ohmic model, while the quasiparticle tunneling is the source of dissipation in the second. Both of them provide a phase transition in quantitative agreement with the experiments.

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