Statistical Mechanics of Ultrathin Films of Quantum Liquids

The statistical thermodynamics of ultrathin quantum films adsorbed on solid surfaces is discussed from a strictly three-dimensional point of view. The thermodynamic equations of state are expressed in terms of an effective density of single-particle states per unit area, $g\left(E\right)\mathrm{}$. For dilute submonolayers, $g\left(E\right)\mathrm{}$ is related to the phase shifts from atomic scattering off the adsorption surface. For single monolayers, the connection between scattering and thermodynamic behavior is not so apparent.