Scaling of the specific heat of superfluids confined in pores

We investigate the scaling properties of the specific heat of the XY model on lattices H x H x L with L >> H (i.e. in a bar-like geometry) with respect to the thickness H of the bar, using the Cluster Monte Carlo method. We study the effect of the geometry and boundary conditions on the shape of the universal scaling function of the specific heat by comparing the scaling functions obtained for cubic, film, and bar-like geometry. In the presence of physical boundary conditions applied along the sides of the bars we find good agreement between our Monte Carlo results and the most recent experimental data for superfluid helium confined in pores.