Path Integral Monte Carlo Simulations of Thin 4He Films on a H2 Surface

by Marcus Wagner and David M. Ceperley, NCSA Applications Group

Atomically thin 4He films of up to three monolayers on molecular hydrogen (1,1,1) surfaces are studied at T=0.5 K, using path integral Monte Carlo. The binding energy of 4He to the H2 substrate as a function of 4He coverage is computed, and evidence of the prewetting transition is obtained. Density profiles perpendicular to the 4He-H2 interface are obtained, as well as the zero point motion and effective mass of 4He parallel to the substrate surface. The superfluid density of 4He vs. coverage is calculated, and the intermediate scattering function is computed from which the speed of third sound is estimated. Finally the vorticity-vorticity correlation function is calculated.

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