Ground-state properties of two-dimensional liquid and solidHe4

Abstract

Variational calculations of two-dimensional liquid and solid states of ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ interacting by a Lennard-Jones potential are presented. The lowest-energy state of this system at $T=0\mathrm{}$ is shown to be the liquid phase. At higher densities, the system does crystallize. The melting and solidification densities are computed; the melting behavior is compared with the observed melting of solids in two dimensions. The errors of previous approximate calculations are discussed.