M. Kardar et al., UNUSUAL UNIVERSALITY OF BRANCHING INTERFACES IN RANDOM-MEDIA, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 52(2), 1995, pp. 1269-1272
We study the criticality of a Potts interface by introducing a froth m
odel which, unlike its solid-on-solid Ising counterpart, incorporates
bubbles of different phases. The interface is fractal at the phase tra
nsition of a pure system. However, a position space approximation sugg
ests that the probability of loop formation vanishes marginally at a t
ransition dominated by strong random bond disorder. This implies a lin
ear critical interface, and provides a mechanism for the conjectured e
quivalence of critical random Potts and Ising models.