HYPERSCALING AND NONCLASSICAL EXPONENTS FOR THE LINE TENSION AT WETTING

We study the effect of fluctuations on the line tension tau at first-order and continuous wetting transitions. We consider thermal wandering, strong fluctuations as in random media, and weak fluctuations as in quasiperiodic systems. We obtain alpha(l)=alpha(s)+nu(parallel-to), relating the exponent of tau, 2-alpha(l), to the surface specific-heat exponent alpha(s) and the interfacial correlation-length exponent nu(parallel-to). The singular behavior of tau at first-order wetting reveals that a critical phenomenon with a diverging correlation length, akin to complete wetting, is taking place.