PIRSA:13010107  ( MP4 Medium Res , MP4 Low Res , MP3 , PDF ) Which Format?
Superfluid to normal phase transition in strongly interacting bosons in two and three dimensions.
Speaker(s): Juan Carrasquilla
Abstract: Using quantum Monte Carlo simulations, we investigate the finite-temperature phase diagram of hard-core bosons (XY model) in two- and three-dimensional square lattices. To determine the phase boundaries, we perform a finite-size scaling analysis of the condensate fraction and/or the superfluid stiffness. We then discuss how this diagrams can be measured in experiments with trapped ultracold gases, where the systems are inhomogeneous. For that, we introduce a method based on the measurement of the zero-momentum occupation, which is adequate for experiments dealing with both homogeneous and trapped systems. Finally, we provide an analytical argument that demonstrates that the Bose-Hubbard model does not exhibit finite-temperature BEC in two dimensions, provided that density remains finite across the entire system in the thermodynamic limit.
Date: 22/01/2013 - 3:30 pm
Valid XHTML 1.0!