Quasi-classical calculations for superfluids

Frederick Reif

Pierre-François Duc, Michel Savard, Matei Petrescu +2 more

Yongle Yu

R. N. Bisset, P. B. Blakie

The classical field simulation technique is used to study a trapped quasi-two-dimensional Bose gas. We calculate the central curvature of the system density and fluctuations of the condensate mode in the degenerate regime. These results provide new understanding of the system behavior in the region of the superfluid transition.

Akiko Masaki-Kato, Seiji Yunoki, Dai S. Hirashima

We study the superfluid density of hard-core bosons on quasi-one-dimensional lattices using the quantum Monte Carlo method. Because of phase slippage, the superfluid density drops quickly to zero at finite temperatures with increasing the system length $\ensuremath{\ell}$ and the superfluid transition temperature is zero in one spatial dimension and also in quasi-one dimension in the limit of $\ensuremath{\ell}\ensuremath{\rightarrow}\ensuremath{\infty}$. We calculate the superfluid density of a model where no phase slippage is allowed and show that the superfluid density remains finite at finite temperatures even in the one-dimensional limit. We also discuss how finite superfluid density can be observed in a quasi-one-dimensional system using a torsional oscillator.