230 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
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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
Manifestation of strange nonchaotic attractors in extended systems: A study through out-of-time-ordered correlators
We study the spatial spread of out-of-time-ordered correlators (OTOCs) in
coupled map lattices (CMLs) of quasiperiodically forced nonlinear maps. We use
instantaneous speed (IS) and finite-time Lyapunov exponents (FTLEs) to
investigate the role of strange non-chaotic attractors (SNAs) on the spatial
spread of the OTOC. We find that these CMLs exhibit a characteristic on and off
type of spread of the OTOC for SNA. Further, we provide a broad spectrum of the
various dynamical regimes in a two-parameter phase diagram using IS and FTLEs.
We substantiate our results by confirming the presence of SNA using established
tools and measures, namely the distribution of finite-time Lyapunov exponents,
phase sensitivity, spectrum of partial Fourier sums, and test.Comment: 12 pages, 16 figures, 2 table
Comment on ``Intermittent Synchronization in a Pair of Coupled Chaotic Pendula"
The main aim of this comment is to emphasize that the conditional Lyapunov
exponents play an important role in distinguishing between intermittent and
persistent synchronization, when the analytic criteria for asymptotic stability
are not uniformly obeyed.Comment: 2 pages, RevTeX 4, 1 EPS figur
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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