Dresden 2006 – wissenschaftliches Programm
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DY: Dynamik und Statistische Physik
DY 46: Poster
DY 46.117: Poster
Donnerstag, 30. März 2006, 16:00–18:00, P1
Ageing at surfaces: The semi-infinite spherical model — •Florian Baumann1,2 and Michel Pleimling1 — 1Institut für Theoretische Physik I, Universität Erlangen-Nürnberg, Germany — 2Laboratoire de Physique des Matériaux, Université Henri Poincaré Nancy I, France
Ageing phenomena have been considered in many translationally invariant systems. An interesting question is to see what happens if we introduce a spatial surface. In the past [1] numerical investigations were done on this question, and it turned out that surface ageing exponents, surface scaling functions and a surface fluctuation-dissipation ratio can reasonably be defined in close analogy to the bulk case.
Here we aim at adding some exact results to the discussion by considering the semi-infinite kinetic spherical model [2]. We do this for both Dirichlet and Neumann boundary conditions at the surface, which corresponds to the ordinary transition and special transition point respectively. We compute the exact results for the two-time surface correlation and response functions in the dynamical scaling regime as well as the surface fluctuation-dissipation ratio. The results for the critical exponents are in line with previously found scaling relations connecting them to static exponents. We also study the low-temperature phase of this model. Our results show that for Dirichlet boundary conditions the value of the non-equilibrium surface exponent b1 does not vanish, in contrast to the usual bulk value of systems undergoing phase ordering.
[1] M. Pleimling, Phys. Rev. B 70, 104401 (2004)
[2] F. Baumann and M. Pleimling, cond-mat/0509064