277 research outputs found
Dynamics of quasi-one-dimensional bright and vortex solitons of a dipolar Bose-Einstein condensate with repulsive atomic interaction
By numerical and variational analysis of the three-dimensional
Gross-Pitaevskii equation we study the formation and dynamics of bright and
vortex-bright solitons in a cigar-shaped dipolar Bose-Einstein condensate for
large repulsive atomic interactions. Phase diagram showing the region of
stability of the solitons is obtained. We also study the dynamics of breathing
oscillation of the solitons as well as the collision dynamics of two solitons
at large velocities. Two solitons placed side-by-side at rest coalesce to form
a stable bound soliton molecule due to dipolar attraction.Comment: To obtain the included video clips S1, S2, S3 and S4, please download
sourc
Position swapping and pinching in Bose-Fermi mixtures with two-color optical Feshbach resonances
We examine the density profiles of the quantum degenerate Bose-Fermi mixture
of Yb-Yb, experimental observed recently, in the mean field
regime. In this mixture there is a possibility of tuning the Bose-Bose and
Bose-Fermi interactions simultaneously using two well separated optical
Feshbach resonances, and it is a good candidate to explore phase separation in
Bose-Fermi mixtures. Depending on the Bose-Bose scattering length a_\BB, as
the Bose-Fermi interaction is tuned the density of the fermions is pinched or
swapping with bosons occurs.Comment: 8 pages, 7 figure
Dynamics of gap solitons in a dipolar Bose-Einstein condensate on a three-dimensional optical lattice
We suggest and study the stable disk- and cigar-shaped gap solitons of a
dipolar Bose-Einstein condensate of Cr atoms localized in the lowest
band gap by three optical-lattice (OL) potentials along orthogonal directions.
The one-dimensional version of these solitons of experimental interest confined
by an OL along the dipole moment direction and harmonic traps in transverse
directions is also considered. Important dynamics of (i) breathing oscillation
of a gap soliton upon perturbation and (ii) dragging of a gap soliton by a
moving lattice along axial direction demonstrates the stability of gap
solitons. A movie clip of dragging of three-dimensional gap soliton is
included.Comment: To see the dragging movie clip please download sourc
Matter wave switching in Bose-Einstein condensates via intensity redistribution soliton interactions
Using time dependent nonlinear (s-wave scattering length) coupling between
the components of a weakly interacting two component Bose-Einstein condensate
(BEC), we show the possibility of matter wave switching (fraction of atoms
transfer) between the components via shape changing/intensity redistribution
(matter redistribution) soliton interactions. We investigate the exact
bright-bright N-soliton solution of an effective one-dimensional (1D) two
component BEC by suitably tailoring the trap potential, atomic scattering
length and atom gain or loss. In particular, we show that the effective 1D
coupled Gross-Pitaevskii (GP) equations with time dependent parameters can be
transformed into the well known completely integrable Manakov model described
by coupled nonlinear Schr\"odinger (CNLS) equations by effecting a change of
variables of the coordinates and the wave functions under certain conditions
related to the time dependent parameters. We obtain the one-soliton solution
and demonstrate the shape changing/matter redistribution interactions of two
and three soliton solutions for the time independent expulsive harmonic trap
potential, periodically modulated harmonic trap potential and kink-like
modulated harmonic trap potential. The standard elastic collision of solitons
occur only for a specific choice of soliton parameters.Comment: 11 pages, 14 figures, 1 tabl
Localization of a dipolar Bose-Einstein condensate in a bichromatic optical lattice
By numerical simulation and variational analysis of the Gross-Pitaevskii
equation we study the localization, with an exponential tail, of a dipolar
Bose-Einstein condensate (DBEC) of Cr atoms in a three-dimensional
bichromatic optical-lattice (OL) generated by two monochromatic OL of
incommensurate wavelengths along three orthogonal directions. For a fixed
dipole-dipole interaction, a localized state of a small number of atoms () could be obtained when the short-range interaction is not too attractive
or not too repulsive. A phase diagram showing the region of stability of a DBEC
with short-range interaction and dipole-dipole interaction is given
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