DIFFUSION MONTE-CARLO STUDY OF 2-DIMENSIONAL LIQUID-HE-4

The ground-state properties of two-dimensional liquid He-4 at zero tem perature are studied by means of a quadratic diffusion Monte Carlo met hod. As interatomic potential we use a revised version of the HFDHE2 A ziz potential which is expected to give a better description of the in teraction between helium atoms. The equation of state is determined wi th great accuracy over a wide range of densities in the liquid phase f rom the spinodal point up to the freezing density. The spinodal decomp osition density is estimated and other properties of the liquid, such as the radial distribution function, static form factor, and density d ependence of the condensate fraction, are all presented.