1,782 research outputs found
Nitsche's method for a Robin boundary value problem in a smooth domain
We prove several optimal-order error estimates for the finite element method
applied to an inhomogeneous Robin boundary value problem for the Poisson
equation defined in a smooth bounded domain in , . The
boundary condition is imposed weakly by the Nische's method. We also study the
symmetric interior penalty discontinuous Galerkin method and prove the same
error estimates. Numerical examples to confirmed our results are also reported.Comment: 16 pages, 7 figure
Breaking of Chiral Symmetry and Spontaneous Rotation in a Spinor Bose-Einstein Condensate
We show that a spin-1 Bose-Einstein condensate with ferromagnetic
interactions spontaneously generates a topological spin texture, in which the m
= \pm 1 components of the magnetic sublevels form vortices with opposite
circulations. This phenomenon originates from an interplay between
ferromagnetic interactions and spin conservation.Comment: 5 pages, 4 figure
Can Spinor Dipolar Effects be Observed in Bose-Einstein Condensates?
Weak dipolar effects in atomic Bose-Einstein condensates (BECs) have recently
been predicted to develop spin textures. However, observation of these effects
requires magnetic field as low as G for spin-1 alkali BECs, so
that they are not washed out by the Zeeman effect. We present a scheme to
observe the magnetic dipole-dipole interaction in alkali BECs under a realistic
magnetic field of mG. Our scheme enables us to extract genuine
dipolar effects and should apply also to Cr BECs.Comment: 4 pages, 3 figure
Einstein--de Haas Effect in Dipolar Bose-Einstein Condensates
The general properties of the order parameter for a dipolar spinor
Bose-Einstein condensate are discussed based on symmetries of interactions. An
initially spin-polarized dipolar condensate is shown to dynamically generate a
non-singular vortex via spin-orbit interactions -- a phenomenon reminiscent of
the Einstein--de Haas effect in ferromagnets.Comment: 4 pages, 4 figures; Final versio
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