Diffusion of interacting Brownian particles on non-regularly spaced stepped structures

Abstract

In this paper, we investigate the diffusion process of interacting Brownian particles on stepped surfaces through a Langevin dynamic simulation method. Our primary interest is the investigation of the dynamics properties by calculating the collective diffusion coefficient for non-regularly spaced stepped structures using the Frenkel–Kontorova repulsive interactions. In particular, we have studied the effects of the Ehrlich–Schwoebel barrier \(E_{S}\) and the additional binding energy \(E_{B}\) on the diffusion process. Overall, our simulation results show that the value of the diffusion coefficient \(D\) is reduced with increasing \(E_{S}\) and \(E_{B}\). This reduction is also observed when decreasing the size of terraces. This diminution is well interpreted by calculating the effective potential which includes the effect of both potentials of Frenkel–Kontorova and the substrate.