Diffusion Monte Carlo study of two-dimensional liquid He-4

The ground-state properties of two-dimensional liquid He-4 at zero temperature are studied by means of a quadratic diffusion Monte Carlo method. As interatomic potential we use a revised version of the HFDHE2 Aziz potential which is expected to give a better description of the interaction between helium atoms. The equation of state is determined with great accuracy over a wide range of densities in the liquid phase from the spinodal point up to the freezing density. The spinodal decomposition density is estimated and other properties of the liquid, such as the radial distribution function, static form factor, and density dependence of the condensate fraction, are all presented.