From nonwetting to prewetting: the asymptotic behavior of 4He drops on alkali substrates

TL;DR

This paper studies how helium-4 droplets spread on alkali surfaces at zero temperature, revealing their transition from nonwetting to prewetting behavior as the droplet size increases, using density functional theory.

Contribution

It provides a detailed analysis of the asymptotic behavior of helium-4 droplets on alkali substrates, connecting nanoscopic droplet properties to macroscopic wetting phenomena.

Findings

Large droplets exhibit properties similar to prewetting films.

Size effects influence the transition from nonwetting to wetting.

Asymptotic properties align with prewetting behavior.

Abstract

We investigate the spreading of 4He droplets on alkali surfaces at zero temperature, within the frame of Finite Range Density Functional theory. The equilibrium configurations of several 4He_N clusters and their asymptotic trend with increasing particle number N, which can be traced to the wetting behavior of the quantum fluid, are examined for nanoscopic droplets. We discuss the size effects, inferring that the asymptotic properties of large droplets correspond to those of the prewetting film.