Effect of drift on segregation in two-component diffusion-limited aggregation

An effect of drift is investigated on the segregation pattern in diffusion-limited aggregation (DLA) with two components (A and B species). The sticking probability ${\mathit{P}}_{\mathit{A}\mathit{B}}$ (=${\mathit{P}}_{\mathit{B}\mathit{A}}$) between the different species is introduced into the DLA model with drift, where the sticking probability ${\mathit{P}}_{\mathit{A}\mathit{A}}$ (=${\mathit{P}}_{\mathit{B}\mathit{B}}$) between the same species equals 1. By using computer simulation it is found that the drift has an important effect on not only the morphology but also the segregation pattern. Under the drift and the small sticking probability, a characteristic pattern appears where elongated clusters of A species and of B species are periodically dispersed. The period decreases with increasing drift. The periodic structure of the deposits is characterized by an autocorrelation function. The shape of the cluster consisting of only A species (or B species) shows a vertically elongated filamentlike structure. Each cluster becomes vertically longer with decreasing sticking probability ${\mathit{P}}_{\mathit{A}\mathit{B}}$. The segregation pattern is distinctly different from that with no drift and a small sticking probability ${\mathit{P}}_{\mathit{A}\mathit{A}}$. The effect of the concentration on the segregation pattern is also shown.