Speaker
Dr
Elife Karabulut
(Lund University)
Description
The high degree of tunability and flexible control are the
two important features associated with cold atomic gases,
which have so far paved the way for various applications
including ow-dimensional systems, confining potentials with
different functional forms, multi-component Bose-Einstein
condensates (BECs), quantum gases with different inter-particle
interactions, etc. Systems with one or more of these
properties exhibit remarkably rich physics, which is
interesting to study either experimentally or
theoretically.
A good example to see the effect of such properties
coexisting in a system is a low-dimensional dipolar Bose
gas. Low-dimensional confinements offer the opportunity
to study the effects of dipolar interaction without instability
problems caused by the head-to-tail alignment of dipoles
in three dimensions. To investigate the anisotropic
character of the interaction, we consider a rotating dipolar BEC
confined in an annular trap for an arbitrary orientation
of the dipoles with respect to their plane of motion.
Within the mean-field approximation, we find that the system
exhibits different vortex configurations depending on the
polarization angle of the dipoles and on the relative
strength between the dipolar and the contact
interactions.
Another example of such a system is a two-component
BEC confined in an anharmonic potential. Confining potentials
rising more steeply than quadratically allow the study of
rapidly rotating BECs, which introduce many novel
phases. This picture becomes even more interesting in the case
of a multi-component BEC . We investigate the rotational
properties of a two-component BEC, which is confined in
an anharmonic trapping potential using both numerical and
analytic methods. More specifically, with the use of a
variational approach we derive analytically the phase
diagram of the system as a function of the rotational
frequency of the trap and of the coupling constant for
sufficiently weak values of the anharmonicity and of the
coupling. The more general structure of the phase
diagram is investigated numerically. We compare our results
with the ones of (i) a single-component BEC confined in an
anharmonic potential, and (ii) a two-component BEC, which is
confined in a harmonic trapping potential.
Primary author
Dr
Elife Karabulut
(Lund University)
