Corrugation-induced first-order wetting: An effective Hamiltonian study

We consider an effective Hamiltonian description of critical wetting transitions in systems with short-range forces at a corrugated (periodic) wall. We are able to recover the results obtained previously from a "microscopic" density-functional approach in which the system wets in a discontinuous manner when the amplitude of the corrugations reaches a critical size A*. Using the functional renormalization group, we find that A* becomes dependent on the wetting parameter omega in such a way as to decrease the extent of the first- order regime. Nevertheless, we still expect wetting in the three-dimensional Ising model to proceed in a discontinuous manner for small deviations of the wall from the plane.