Flux front penetration in disordered superconductors.
We investigate flux front penetration in a disordered type-II superconductor by molecular dynamics simulations of interacting vortices and find scaling laws for the front position and the density profile. The scaling can be understood by performing a coarse graining of the system and writing a disordered nonlinear diffusion equation. Integrating numerically the equation, we observe a crossover from flat to fractal front penetration as the system parameters are varied. The value of the fractal dimension indicates that the invasion process is described by gradient percolation.
Zapperi
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INFM sezione di Roma 1, Dipartimento di Fisica, Università La Sapienza, P.le A. Moro 2, 00185 Roma, Italy.
Moreira
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Andrade
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