Berlin 2005 – wissenschaftliches Programm
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DY: Dynamik und Statistische Physik
DY 50: Critical Phenomena and Phase Transitions
DY 50.4: Vortrag
Mittwoch, 9. März 2005, 10:45–11:00, TU H3010
Evolution of equilibrium droplets — •Andreas Nußbaumer, Elmar Bittner, and Wolfhard Janke — Institut für Theoretische Physik, Universität Leipzig, Augustusplatz 10/11, 04109 Leipzig
At the critical temperature Tc the spin-1/2 Ising model exhibits a phase transition and for temperatures below Tc there exists a spontaneous manetisation ± m0(T). It is well known, that the distribution of the magnetisation P(m,T) has a double peak-structure divided by a flat valley and that the peaks correspond to the so called "droplet" regime and the valley to the "strip" regime.
Following the analytic work of Leung and Zia [1] we used Monte Carlo (MC) simulations to identify the transition point between the droplet- and the strip regime in two and three dimensions. In both cases the Monte Carlo data was matched with data from the “Surface Evolver”, a software to calculate minimal surfaces providing evidence for the exact transition mechanism.
Furthermore, using similar MC algorithms we observed the evaporation/condensation transition. When properly rescaled, our data confirm the analytical results found in [2], showing the absence of droplets of intermediate size.
[1] K. Leung and R. Zia, Geometrically induced transitions between equilibrium crystal shapes, J. Phys. A 23, 54 4593 (1990).
[2] M. Biskup, L. Chayes and R. Kotecky, On the formation/dissolution of equilibrium droplets, Europhys. Lett. 60, 21-27 (1990).