IS THERE A LIQUID-PHASE IN A (SUB)MONOLAYER OF HE-3 ADSORBED ON GRAPHITE

Variational Monte Carlo calculations on two dimensional He-3 adsorbed on graphite show that the uniform fluid phase is unstable with respect to a self bound fluid. Taking into account the delocalisation of the He-3 atoms perpendicular to the substrate is essential to obtain this self-bound state. We discuss the likely consequences of this result on the phase diagram of this system. Heat capacity measurements of Greywall et al. and spin susceptibility measurements of Saunders et al. are discussed in the light of this new finding. Explanations of some anomalies and unexplained features of the experimental results are proposed.