Multicriticality of Wetting, Prewetting, and Surface Transitions

The global phase diagram for wall and surface critical phenomena is analyzed in the space of temperature, surface enhancement, and bulk and surface fields, on the basis of Landau phenomenological theory. Features probably valid for various real systems are the physical unity of prewetting and pure surface criticality, and novel exponents for critical wetting and for a wetting tricritical point, which terminates the region of normal first-order wetting.