6533b85bfe1ef96bd12bbe96

RESEARCH PRODUCT

A dynamical mean field theory for the study of surface diffusion constants

Tapio Ala-nissilaTapio Ala-nissilaTapio Ala-nissilaJuha MerikoskiJuha MerikoskiJuha MerikoskiIlpo VattulainenIlpo VattulainenSee-chen YingT. Hjelt

subject

PhysicsSurface diffusionLangmuirStatistical Mechanics (cond-mat.stat-mech)Monte Carlo methodFOS: Physical sciencesSurfaces and InterfacesCondensed Matter - Soft Condensed MatterCondensed Matter PhysicsCombined approachSurfaces Coatings and FilmsFormalism (philosophy of mathematics)Jump rateDynamical mean field theoryTRACERMaterials ChemistrySoft Condensed Matter (cond-mat.soft)Statistical physicsCondensed Matter - Statistical Mechanics

description

We present a combined analytical and numerical approach based on the Mori projection operator formalism and Monte Carlo simulations to study surface diffusion within the lattice-gas model. In the present theory, the average jump rate and the susceptibility factor appearing are evaluated through Monte Carlo simulations, while the memory functions are approximated by the known results for a Langmuir gas model. This leads to a dynamical mean field theory (DMF) for collective diffusion, while approximate correlation effects beyond DMF are included for tracer diffusion. We apply our formalism to three very different strongly interacting systems and compare the results of the new approach with those of usual Monte Carlo simulations. We find that the combined approach works very well for collective diffusion, whereas for tracer diffusion the influence of interactions on the memory effects is more prominent.

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