Critical wetting out of equilibrium: from high to low system dimensionalities
Abstract Book of the XXIII IUPAP International Conference on Statistical Physics, Genova, Italy, (9-13 July 2007)Abstract
Much scientific effort has been devoted to the study of equilibrium wetting
since the idea that wetting can be described as a phase transition was
introduced by Cahn in the late seventies. Nonequilibrium wetting, however,
has only been recently addressed. Here, critical wetting transitions under
nonequilibrium conditions are studied by analyzing Kardar-Parisi-Zhang (KPZ) interfaces in the presence of a binding substrate. In the case of high system dimensionalties, a self-consistent mean-field method is used. For a positive KPZ nonlinearity, a single (Gaussian) regime is found. On the contrary, interfaces corresponding to negative nonlinearities lead to three different regimes of critical behavior for the surface order-parameter: (i) a trivial Gaussian
regime, (ii) a weak-fluctuation regime with a trivially located critical point and nontrivial exponents, and (iii) a highly non-trivial strong-fluctuation regime, for which we provide a full solution.
Low system dimensionalites are investigated by studying numerically
one dimensional systems with a negative KPZ nonlinear coefficient,
which are characterized in detail by providing the critical exponents for both the average height and the surface order-parameter. Evidence is shown that the presence of a potential well induces an anomalous scaling of the slopes which is not present in the complete wetting scenario.
Ref.:
1.
Critical wetting of a class of nonequilibrium interfaces:
A mean-field picture,
F. de los Santos, E. Romera, O. Al Hammal, and M.A. Muñoz,
Phys. Rev. E 75, 031105 (2007).
2.
Critical wetting of a class of nonequilibrium interfaces:
A computer simulation study,
E. Romera, F. de los Santos, O. Al Hammal, and M.A. Muñoz.
submitted.