Anomalous Roughness in Dimer-Type Surface Growth

We point out how geometric features affect the scaling properties of non-equilibrium dynamic processes, by a model for surface growth where particles can deposit and evaporate only in dimer form, but dissociate on the surface. Pinning valleys (hill tops) develop spontaneously and the surface facets for all growth (evaporation) biases. More intriguingly, the scaling properties of the rough one dimensional equilibrium surface are anomalous. Its width, $W\sim L^\alpha$, diverges with system size $L$, as $\alpha={1/3}$ instead of the conventional universal value $\alpha={1/2}$. This originates from a topological non-local evenness constraint on the surface configurations.