Two parameters for three-dimensional wetting transitions

PACS. 68.10−m – Fluid surfaces and fluid-fluid interfaces. PACS. 64.60Fr – Equilibrium properties near critical points, critical exponents. PACS. 82.65−i – Surface and interface chemistry. Abstract. – Critical effects at complete and critical wetting in three dimensions are studied using a coupled effective Hamiltonian H[s(y), `(y)]. The model is constructed via a novel variational principle which ensures that the choice of collective coordinate s(y) near the wall is optimal. We highlight the importance of a new wetting parameter Ω(T) which has a strong influence on critical properties and allows the status of long-standing Monte Carlo simulation controversies to be re-examined. A suitable microscopic starting point for modelling fluid adsorption in systems with short-ranged forces at a planar wall (situated at z = 0) is the Landau-Ginzburg-Wilson (LGW