Satunnaisesti häirittyjen systeemien tutkimus

Aalto yliopisto / Tapio Ala-Nissilä

Käynnisssä monia projekteja ja tuloksia paljon, yhteenveto eräistä keskeisistä projekteista: Modern statistical and condensed matter physics is among the most competitive and rapidly growing fields of physics. The research program concentrates on the theory of equilibrium and nonequilibrium critical phenomena and dynamics in many-body systems, in particular as applied to complex systems, polymers, disordered materials, and surface physics. A charasteristic feature of the research is the combination of analytic and numercal methods, including Molecular Dynamics (MD) and Monte Carlo (MC) simulation methods. 1. Dynamics of Diffusion, Growth and Spreading on Surfaces We are continuing our previous work on developing the theory of diffusion for strongly interacting systems, such as surface absorbates and polymer chains on surfaces. Spreading dynamics of tiny polymer droplets will be simulated by MD methods. Growth problems will be studied for stepped surfaces of some transition and noble metals, in particular under beam epitaxy conditions (island formation, stability of stepped surfaces and multilayer growth). MC simulation methods will be employed in part here. 2. Dynamical Processes in Disordered Fibre Networks We will study the dynamics and kinetic roughening of slow combustion and fluid fronts in disordered media, and paper in particular. Various theoretical approaches for these problems are under development, and some of them have been studied in detail. Deposition models of structurally disordered materials (fiber networks) have been studied from the point of view of theory of percolation processes and spatial correlations, and this work continues with MC simulations. Theory and a numerical model of sedimentation dynamics of particles in fluids (two-phase flow) has been developed. 3. Adatom Dynamics and Chemical Reactions on Smooth and Vicinal Metal Surfaces Basic energetics of adatom diffusion on catalytically active metal subtrates will be studied using state-of-the-art first principles calculations and phenomenological methods. These calculations rely heavily on numerical methods. The data will be used to study diffusion and other dynamical processes related to chemical reactions. The properties of vicinal surfaces will also be studied, and adatom dynamics on them will be simulated with the MC method. Large-Scale Monte Carlo and Molecular Dynamics simulations. Lasketaan elektronihiloja H/Pt -steppipinnoille