Superfluidity with and without a condensate in two and three dimensions
Faculty of Sciences. Physics
Physics and chemistry of liquids. - London
, p. 819-821
University of Antwerp
The recent study of He and You [P.-S. He and W.-L. You, Int. J. Mod. Phys. B26, 1250107 (2012)] on the relation between superfluid and condensate densities in a two-dimensional weakly interacting Boson system assumed a delta(x - x') interaction between two particles at sites x and x'. The main purpose of this article is to point out the sensitivity of the conclusions of He and You to the choice of interaction. Thus, it is known for logarithmic interactions that one can have superfluidity without a condensate. Finally, some related ideas are mentioned in relation to superfluidity in liquid He-4 at exceedingly low temperatures.