Bose-Einstein Condensation at a Helium Surface
arXiv:cond-mat/0201477 · doi:10.1103/PhysRevLett.89.015301
Abstract
Path Integral Monte Carlo was used to calculate the Bose-Einstein condensate fraction at the surface of a helium film at $T=0.77 K$, as a function of density. Moving from the center of the slab to the surface, the condensate fraction was found to initially increase with decreasing density to a maximum value of 0.9 before decreasing. Long wavelength density correlations were observed in the static structure factor at the surface of the slab. Finally, a surface dispersion relation was calculated from imaginary-time density-density correlations.
8 pages, 5 figures