14 research outputs found
Transport dynamics of ultracold atoms in a triple-well transistor-like potential
The transport of atoms is experimentally studied in a transistor-like
triple-well potential consisting of a narrow gate well surrounded by source and
drain wells. Atoms are initially loaded into the source well with
pre-determined temperature and chemical potential. Energetic atoms flow from
the source, across the gate, and into the drain where they are removed using a
resonant light beam. The manifestation of atom-atom interactions and
dissipation is evidenced by a rapid population growth in the initially vacant
gate well. The transport dynamics are shown to depend strongly on a feedback
parameter determined by the relative heights of the two barriers forming the
gate region. For a range of feedback parameter values, experiments establish
that the gate atoms develop a larger chemical potential and lower temperature
than those in the source.Comment: 13 pages, 5 figures, accepted for publication in NJ
Undamped nonequilibrium dynamics of a nondegenerate Bose gas in a 3D isotropic trap
We investigate anomalous damping of the monopole mode of a non-degenerate 3D
Bose gas under isotropic harmonic confinement as recently reported by the JILA
TOP trap experiment [D. S. Lob- ser, A. E. S. Barentine, E. A. Cornell, and H.
J. Lewandowski (in preparation)]. Given a realistic confining potential, we
develop a model for studying collective modes that includes the effects of
anharmonic corrections to a harmonic potential. By studying the influence of
these trap anharmonicities throughout a range of temperatures and collisional
regimes, we find that the damping is caused by the joint mechanisms of
dephasing and collisional relaxation. Furthermore, the model is complimented by
Monte Carlo simulations which are in fair agreement with data from the JILA
experiment.Comment: 11 pages, 6 figure