INTERMITTENT DYNAMICS AND SELF-ORGANIZED DEPINNING IN PROPAGATING FRONTS

We study the roughening dynamics of a two-dimensional front where adva nces are made at minimal pinning sites, while slopes of the front are kept finite by additional lateral growth. The interface self-organizes toward a critical state with long-range correlations in space and tim e. The dynamics is governed by intermittent bursts which give rise to a scale-invariant avalanche distribution and multiscaling of the tempo ral roughening. Generalizing a recently proposed theory for the one-di mensional case, we demonstrate that the multiscaling can be explained by the static roughness exponent alone. The correlation between subseq uent deposition activities exhibits the same power law as in the. one- dimensional case.