4,504 research outputs found
Phase separation in a spin-orbit coupled Bose-Einstein condensate
We study a spin-orbit (SO) coupled hyperfine spin-1 Bose-Einstein condensate
(BEC) in a quasi-one-dimensional trap. For a SO-coupled BEC in a
one-dimensional box, we show that in the absence of the Rabi term, any non-zero
value of SO coupling will result in a phase separation among the components for
a ferromagnetic BEC, like Rb. On the other hand, SO coupling favors
miscibility in a polar BEC, like Na. In the presence of a harmonic trap,
which favors miscibility, a ferromagnetic BEC phase separates, provided the
SO-coupling strength and number of atoms are greater than some critical value.
The Rabi term favors miscibility irrespective of the nature of the spin
interaction: ferromagnetic or polar
Vector solitons in a spin-orbit coupled spin- Bose-Einstein condensate
Five-component minimum-energy bound states and mobile vector solitons of a
spin-orbit-coupled quasi-one-dimensional hyperfine-spin-2 Bose-Einstein
condensate are studied using the numerical solution and variational
approximation of a mean-field model. Two distinct types of solutions with
single-peak and multi-peak density distribution of the components are
identified in different domains of interaction parameters. From an analysis of
Galilean invariance and time-reversal symmetry of the Hamiltonian, we establish
that vector solitons with multi-peak density distribution preserve
time-reversal symmetry, but cannot propagate maintaining the shape of
individual components. However, those with single-peak density distribution
violate time-reversal symmetry of the Hamiltonian, but can propagate with a
constant velocity maintaining the shape of individual components
Mobile vector soliton in a spin-orbit coupled spin- condensate
We study the formation of bound states and three-component bright vector
solitons in a quasi-one-dimensional spin-orbit-coupled hyperfine spin
Bose-Einstein condensate using numerical solution and variational approximation
of a mean-field model. In the antiferromagnetic domain, the solutions are
time-reversal symmetric, and the component densities have multi-peak structure.
In the ferromagnetic domain, the solutions violate time-reversal symmetry, and
the component densities have single-peak structure. The dynamics of the system
is not Galelian invariant. From an analysis of Galelian invariance, we
establish that the single-peak ferromagnetic vector solitons are true solitons
and can move maintaining constant component densities, whereas the
antiferromagnetic solitons cannot move with constant component densities
Isospin effects on the mass dependence of balance energy
We study the effect of isospin degree of freedom on balance energy throughout
the mass range between 50 and 350 for two sets of isotopic systems with N/Z =
1.16 and 1.33 as well as isobaric systems with N/Z = 1.0 and 1.4. Our findings
indicate that different values of balance energy for two isobaric systems may
be mainly due to the Coulomb repulsion. We also demonstrate clearly the
dominance of Coulomb repulsion over symmetry energy.Comment: 5 pages, 3 figures In this version the discussion is in terms of N/Z
whereas in the journal the whole discussion is in terms of N/A. The
conclusions remain unaffecte
Spontaneous symmetry breaking in a spin-orbit coupled spinor condensate
We study the ground-state density profile of a spin-orbit coupled
spinor condensate in a quasi-one-dimensional trap. The Hamiltonian of the
system is invariant under time reversal but not under parity. We identify
different parity- and time-reversal-symmetry-breaking states. The
time-reversal-symmetry breaking is possible for degenerate states. A phase
separation among densities of different components is possible in the domain of
time-reversal-symmetry breaking. Different types of parity- and
time-reversal-symmetry-breaking states are predicted analytically and studied
numerically. We employ numerical and approximate analytic solutions of a
mean-field model in this investigation to illustrate our findings
Vortex reconnections between coreless vortices in binary condensates
Vortex reconnections plays an important role in the turbulent flows
associated with the superfluids. To understand the dynamics, we examine the
reconnections of vortex rings in the superfluids of dilute atomic gases
confined in trapping potentials using Gross-Petaevskii equation. Furthermore we
study the reconnection dynamics of coreless vortex rings, where one of the
species can act as a tracer.Comment: 9 pages, Proceeding from International Conference On Complex
Processes in Plasmas and Nonlinear Dynamical Systems, Gandhinagar, India
(November 2012
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