Surface diffusion on a triangular lattice system: Effect of the repulsive interactions on the current correlation functions

In this paper, we consider a triangular lattice and we investigate the behavior of current correlation functions within a small circular region in a surface which represents the probe area in the scanning tunneling microscopy experiments. The calculations are done in the framework of the mean field lattice gas model. We found that the correlation function varies with the coverage p and with the reduced interaction energy γ as p exp ( 8 γ p ) . However, it behaves in the long time regime as exp(−t/τr). We have also studied the effect of the interaction between the adatoms on their diffusion process by calculating the effective collective diffusion coefficient D c eff and the collective diffusion coefficient Dc using the linear response theory. The effective collective diffusion coefficient D c eff shows more interesting results for which the structure appears respectively at p = 1/3 and p = 2/3 reflecting the effect of ordered phase establishment.