First-Passage Percolation under extreme disorder: from bond-percolation to Kardar-Parisi-Zhang universality

TL;DR

This paper investigates the effects of strong disorder on first-passage percolation in 2D lattices, revealing a crossover from bond-percolation universality to KPZ behavior as disorder increases.

Contribution

It introduces a new crossover length scale in strong disorder regimes, linking bond-percolation universality to KPZ scaling in FPP models.

Findings

Bond-percolation critical exponents are reproduced in the strong-disorder regime.

A new characteristic length scale diverges at infinite disorder.

The crossover between percolation and KPZ regimes is governed by properties of the link-time distribution.

Abstract

We consider the statistical properties of arrival times and balls on first-passage percolation (FPP) $2D$ square lattices with strong disorder in the link-times. A previous work showed a crossover in the weak disorder regime, between Gaussian and Kardar-Parisi-Zhang (KPZ) universality, with the crossover length decreasing as the noise amplitude grows. On the other hand, this work presents a very different behavior in the strong-disorder regime. A new crossover length appears below which the model is described by bond-percolation universality class. This characteristic length scale grows with the noise amplitude and diverges at the infinite-disorder limit. We provide a thorough characterization of the bond-percolation phase, reproducing its associated critical exponents through a careful scaling analysis of the balls. This is carried out through to a continuous mapping of the FPP passage time into the occupation probability of the bond-percolation problem. Moreover, the crossover length can be explained merely in terms of properties of the link-time distribution. The interplay between the new characteristic length and the correlation length intrinsic to bond-percolation determines the crossover between the initial percolation-like growth and theasymptotic KPZ scaling.