7,163 research outputs found
Three-dimensional gap solitons in Bose-Einstein condensates supported by one-dimensional optical lattices
We study fundamental and compound gap solitons (GSs) of matter waves in
one-dimensional (1D) optical lattices (OLs) in a three-dimensional (3D)
weak-radial-confinement regime, which corresponds to realistic experimental
conditions in Bose-Einstein condensates (BECs). In this regime GSs exhibit
nontrivial radial structures. Associated with each 3D linear spectral band
exists a family of fundamental gap solitons that share a similar transverse
structure with the Bloch waves of the corresponding linear band. GSs with
embedded vorticity may exist \emph{inside} bands corresponding to other
values of . Stable GSs, both fundamental and compound ones (including vortex
solitons), are those which originate from the bands with lowest axial and
radial quantum numbers. These findings suggest a scenario for the experimental
generation of robust GSs in 3D settings.Comment: 5 pages, 5 figures; v2: matches published versio
Critical Temperature Shift in Weakly Interacting Bose Gas
With a high-performance Monte Carlo algorithm we study the
interaction-induced shift of the critical point in weakly interacting
three-dimensional -theory (which includes quantum Bose gas). In terms
of critical density, , mass, , interaction, , and temperature, ,
this shift is universal: , the constant
found to be equal to . For quantum Bose gas with the
scattering length this implies , with
.Comment: 4 pages, latex, 3 figure
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