Surface structure of liquid He4

A variational method developed for studying the surface properties of fermion liquids is adapted for use with liquid He4. It is compared both numerically and analytically with our previous approach. The new method at this level requires a more drastic approximation on the short-range correlation functions, but promises to be more tractable and attractive on the next level of sophistication. In the meantime, numerical results support our earlier conclusion that a mild density overshoot exists near the free surface. Here we find an overshoot of about 12% and a surface tension of 0.238 K -2 as compared to the experimental value of 0.27 K -2.