Homogeneous and self-similar diffusion-limited aggregation including surface-diffusion processes

Growth features of aggregates including surface-diffusion processes are studied by Monte Carlo simulations on a two-dimensional square lattice. A dendritic pattern with thick branches changes its anisotropy from the 10 direction to 11 depending on the surface-diffusion mechanism. A homogeneous diffusion-limited-aggregation (DLA) pattern with a fractal dimension of df=1.7160.003 grows in the crossover domain between two anisotropies. Results indicate that a random tip-splitting process arising from noise is necessary to hold its homogeneity and self-similarity. Such processes in other DLA patterns and in a dense radial-like pattern obtained from altered simulations are also investigated.