Percolation model for the superconductor-insulator transition in granular films

Abstract

We study the temperature dependence of the superconductor-insulator transition in granular superconductors. Empirically, these systems are characterized by very broad resistance tails, which depend exponentially on the temperature, and the normal state resistance. We model these systems by a two-dimensional random resistor percolation networks in which the resistance between two grains is governed either by Josephson junction coupling or by quasi particle tunneling. Our numerical simulations as well as an effective medium evaluation explain the experimental results over a wide range of temperatures and resistances. Using effective medium approximation we find an analytical expression for the effective resistance of the system and the value of the critical resistance separating conducting from insulating branches.

arXiv comment4 pages, 2 figures

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Cited by in corpus (8)

• Temperature dependence of the bulk energy gap in underdoped Bi-2212: Evidence for the mean-field superconducting transition
• Percolative superconductivity in La2CuO4.06 by lattice granularity patterns with scanning micro X-ray absorption near edge structure
• Ultrasensitive interplay between ferromagnetism and superconductivity in NbGd composite thin films
• Resistive transition in disordered superconductors with varying intergrain coupling
• Anomalous Tail Effect on Resistivity Transition and Weak-link Behavior of Iron Based Superconductor
• Characterizing the insulator adjacent to the superconductor in Bi${}_2$Sr${}_{2-x}$La${}_x$CuO${}_{6+\delta }$ ($x=0.3$)
• Quasi-${\Phi }_0$-periodic supercurrent at quantum Hall transitions
• Percolative supercurrent in superconductor-ferromagnetic insulator bilayers