N. Schultka et E. Manousakis, SPECIFIC-HEAT OF SUPERFLUIDS NEAR THE TRANSITION-TEMPERATURE, Physical review. B, Condensed matter, 52(10), 1995, pp. 7528-7536
The specific heat of the x-y model is studied on cubic lattices of siz
es L x L x L and on lattices L x L x H with L much greater than H (i.e
., on lattices representing a film geometry) using the cluster Monte C
arlo method. Periodic boundary conditions were applied in all directio
ns. In the cubic case we obtained the ratio of the critical exponents
alpha/nu from the size dependence of the energy density at the critica
l temperature T-lambda. Using finite-size scaling theory, we find that
while for both geometries our results scale to universal functions, t
hese functions differ for the different geometries. We compare our fin
dings to experimental results and results of renormalization-group cal
culations.