Abstract
We calculate the superfluid transition temperature of homogeneous interacting Bose gases in three and two spatial dimensions using large-scale path integral Monte Carlo simulations (with up to particles). In 3D we investigate the limits of the universal critical behavior in terms of the scattering length alone by using different models for the interatomic potential. We find that this type of universality sets in at small values of the gas parameter . This value is different from the estimate for the validity of the asymptotic expansion in the limit of vanishing . In 2D we study the Berezinskii-Kosterlitz-Thouless transition of a gas with hard-core interactions. For this system we find good agreement with the classical lattice model up to very large densities. We also explain the origin of the existing discrepancy between previous studies of the same problem.
- Received 22 January 2008
DOI:https://doi.org/10.1103/PhysRevLett.100.140405
©2008 American Physical Society