Non-Ornstein-Zernike surface structure factor for complete wetting in three (and above) dimensions

Publisher Website
Google Scholar
Abstract
We have derived a closed form expression for the transverse Fourier transform G(0, 0; Q) (or surface structure factor) of the surface spin-spin correlation function near a complete wetting transition from Landau theory. Whilst G(0,0;Q) contains isolated singularities (poles) in the complex wavevector plane it does not have a simple Omstein-Zernike (OZ) form. Instead, the function exhibits two limiting OZ-like behaviours characteristic of intrinsic and coherent capillary-wave-like fluctuations depending on the value of the scaling variable Q mod H mod /sub ///-Vco. We also discuss the decay of surface correlations in real space and identify the appropriate singular (long-ranged) contribution. In contrast to the second-moment correlation length the true correlation length at the wall diverges as mod H mod /sub ///-V infinity in the limit of complete wetting.