Quantum Markovian activated surface diffusion of interacting adsorbates

TL;DR

This paper introduces a quantum Markovian model for atom-surface diffusion with interactions, revealing quantum effects at low temperatures and coverages, and analyzing Na atom diffusion on copper surfaces.

Contribution

It presents a novel quantum Markovian activated diffusion model that accounts for interactions and analyzes its application to Na atom diffusion on copper surfaces.

Findings

Quantum effects influence diffusion at low temperatures and coverages.

The model separates classical-like and quantum-mechanical factors in the scattering function.

Quantum tunneling is not necessary for quantum effects in this context.

Abstract

A quantum Markovian activated atom-surface diffusion model with interacting adsorbates is proposed for the intermediate scattering function, which is shown to be complex-valued and factorizable into a classical-like and a quantum-mechanical factor. Applications to the diffusion of Na atoms on flat (weakly corrugated) and corrugated-Cu(001) surfaces at different coverages and surface temperatures are analyzed. Quantum effects are relevant to diffusion at low surface temperatures and coverages even for relatively heavy particles, such as Na atoms, where transport by tunneling is absent.