Monte Carlo simulation of a helium film on graphite

Green's-function Monte Carlo and variational methods are used to calculate the properties of a monolayer of helium on a smooth graphite substrate. We find that in all respects these properties are very close to those of two-dimensional helium. There are small differences in the equations of state of the two systems. We use these results to show how accurate chemical potentials can be constructed for particles in the second and third layers and we compute the densities at which these layers will begin to form. These densities art: in good agreement with the experimental values.