A Model for Nonequilibrium Wetting Transitions in Two Dimensions

A simple two dimensional model of a phase growing on a substrate is introduced. The model is characterized by an adsorption rate q, and a desorption rate p. It exhibits a wetting transition which may be viewed as an unbinding transition of an interface from a wall. For p=1, the model may be mapped onto an exactly soluble equilibrium model exhibiting complete wetting with critical exponents gamma = 1/3 for the diverging interface width and x_0 = 1 for the zero-level occupation. For 0 < p != 1 a crossover to different exponents is observed which is related to a KPZ type nonlinearity.