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Center for Nonlinear Studies |
While conventional simulations provide insight in the behavior ofsystems evolving in common thermodynamic ensembles at constanttemperature, generalized-ensemble methods tailor the conditions, oftenin an apparently unphysical fashion, in order to maximize the amountof information extracted from the simulations. The introduction ofsuch schemes is currently revolutionizing the way simulations arecarried out and, in conjunction with coarse-grained models, they canoffer unique insight into universal properties of entire classes ofmaterials. In this talk I will illustrate the power of such advanced approachesusing two recent studies. In the first, we study the formation of smallhelium (He) clusters in bulk tungsten (W), a process of practicalrelevance for fusion energy production. We calculate formation freeenergies of small helium clusters at temperatures up to the meltingpoint of W, encompassing the whole range of interest for fusion-energyproduction. In a second study, we investigate the adsorption of a polymer near anattractive, cylindrical nanosubstrate. We focus on structuraltransitions and discuss their dependence on the temperature and onmodel parameters such as effective substrate thickness and attractionstrength. The result, a complete hyperphase diagram of the polymerphases, provides fundamental insights into the wetting of atomicsurfaces, a key to the development of next-generation,high-performance nanomaterials based on functionalized carbonnanotubes.
Host: Christoph Junghans