Noncondensation of a4He submonolayer film

摘要: A4He film may be modeled only approximately as a two-dimensional (2D) system. This paper calculates the energy shift due to motion in third dimension, thez direction perpendicular surface. Special attention is paid question of whether ground-state solution this quasi-2D problem liquid (as that 2D problem) or gas. Thez has substantial effects case weak-binding surfaces, for which numerical results are obtained. An assessment made various approaches used: perturbation theory and variational, adiabatic, effective potential methods.