296 research outputs found
Line of Dirac monopoles embedded in a Bose-Einstein condensate
The gauge field of a uniform line of magnetic monopoles is created using a
single Laguerre-Gauss laser mode and a gradient in the physical magnetic field.
We study the effect of these monopoles on a Bose condensed atomic gas, whose
vortex structure transforms when more than six monopoles are trapped within the
cloud. Finally, we study this transition with the collective modes
A repulsive atomic gas in a harmonic trap on the border of itinerant ferromagnetism
Alongside superfluidity, itinerant (Stoner) ferromagnetism remains one of the
most well-characterized phases of correlated Fermi systems. A recent experiment
has reported the first evidence for novel phase behavior on the repulsive side
of the Feshbach resonance in a two-component ultracold Fermi gas. By adapting
recent theoretical studies to the atomic trap geometry, we show that an
adiabatic ferromagnetic transition would take place at a weaker interaction
strength than is observed in experiment. This discrepancy motivates a simple
non-equilibrium theory that takes account of the dynamics of magnetic defects
and three-body losses. The formalism developed displays good quantitative
agreement with experiment.Comment: 4 pages, 2 figure
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