UNBINDING TRANSITION OF THE INTERFACE OF A 2-DIMENSIONAL ISING-MODEL SYSTEM WITH A DEFECT ZONE IN THE BULK

By introducing a defect zone instead of a single defect line in the bulk, a modified form of the AB model of Forgacs, Svrakic, and Privman is investigated. It is found that when the defect zone is far away from the substrate the first-order unbinding transition still exists at a temperature T1 below the critical point of the two-dimensional Ising model, while when it is near the substrate no wetting transition can take place because the inhomogeneity constrains the formation of the wetting layer.