Weakly interacting Bose gases in optical lattices: a theoretical scenario to test London's hypothesis
by
DrFernanda Pinheiro(Institute for Biological Physics, University of Cologne)
→
Europe/Stockholm
A5:1041 (OBS!)
A5:1041 (OBS!)
Description
After the discovery of the superfluid behavior of Helium-II, in 1938, London postulated that the
phenomena of superfluidity was a manifestation of the Bose-Einstein condensation. Since then this
statement is usually assumed as valid, as superfluid and condensation properties of many systems are
very commonly studied together, but so far it still remains without a general theoretical proof.
In this presentation I will show the results of the study of Bose-Einstein condensation and superfluidity in
a ring-shaped 1D periodic potential which undergoes rotation. Here the phenomena of superfluidity is
characterized in terms of an inertial parameter, and the approach used allows for the study of the superfluid
fraction without assumptions regarding the condensate mode. Both condensate and superfluid fractions are
compared, and the properties of the zero temperature phase-diagrams are also considered. The results indicate
that for this system condensate and superfluid fractions are quite unrelated in terms of parameter values,
suggesting, thus, that even for dilute gases the interchange of superfluid and condensate fractions should be
considered more carefully.