Non-stochastic behavior of atomic surface diffusion on Cu(111) at all temperatures

TL;DR

This paper reveals that atomic surface diffusion on Cu(111) exhibits correlated behavior at all temperatures, challenging the traditional random walk model and affecting how diffusion coefficients are interpreted.

Contribution

It demonstrates the non-stochastic, correlated nature of atomic jumps on Cu(111) surface across all temperatures, based on Molecular Dynamics simulations.

Findings

Atomic jumps show persistent correlations at all temperatures.

Diffusion cannot be accurately modeled as a simple random walk.

Implications for interpreting diffusion coefficients in surface science.

Abstract

Atomic diffusion is usually understood as a succession of random, independent displacements of an adatom over the surface's potential energy landscape. Nevertheless, an analysis of Molecular Dynamics simulations of self-diffusion on Cu(111) demonstrates the existence of different types of correlations in the atomic jumps at all temperatures. Thus, the atomic displacements cannot be correctly described in terms of a random walk model. This fact has a profound impact on the determination and interpretation of diffusion coefficients.