Scaling of reaction fronts under quenched disorder

The dynamics of fronts in diffusion-limited reactions A + B → C with initially segregated reactants in strongly disordered media is studied. The scaling of the front width, w, in the asymptotic limit w tα, is analyzed as a function of the “disorder strength” and spatial dimensionality, d. We show that exponent a in d dimensions is a monotonic decreasing function of disorder strength, as measured from diffusive properties of reactants. We also find that a has a mean field behavior for d 2. Scaling anomalies are observed in related quantities such as nearest neighbor distance, midpoint fluctuations and concentration profiles of reactants near the center of the front.