16,557 research outputs found
Field methods for rodent studies in Asia and the Indo-Pacific
Farm Management,
Universal and anomalous behavior in the thermalization of strongly interacting harmonically trapped gas mixtures
We report on the dynamics of thermalization by extending a generalization of
the Caldeira-Leggett model, developed in the context of cold atomic gases
confined in a harmonic trap, to higher dimensions. Universal characteristics en
route to thermalization which appear to be independent of dimensionality are
highlighted, which additionally suggest a scaling analogous to turbulent mixing
in fluid dynamics. We then focus on features dependent on dimensionality, with
particular regard to the role of angular momentum of the two atomic clouds,
having in mind the goal of efficient thermalization between the two species.
Finally, by considering asymmetry in species numbers, we find that nonlinear
inter-species interactions provide a mode locking mechanism between the
majority and minority species, relevant to recent experiments involving
Fermi-Bose mixtures in the normal phase.Comment: 11 pages, 8 figures. Submitted to J.Phys.
Quantum science and metrology with mixed-species ion chains
This chapter reviews recent developments in the use of mixed-species ion
chains in quantum information science, frequency metrology and spectroscopy. A
growing number of experiments have demonstrated new methods in this area,
opening up new possibilities for quantum state generation, quantum control of
previously inaccessible ions, and the ability to maintain quantum control over
extended periods. I describe these methods, providing details of the techniques
which are required in order to work with such systems. In addition, I present
perspectives on possible future uses of quantum logic spectroscopy techniques,
which have the potential to extend precision control of atomic ions to a large
range of atomic and molecular species.Comment: 30 pages, 8 figures, revtex4. Review article for Adv. At. Mol. Phys..
Final fully-formatted version will appear in print. Comments welcom
Ultracold atomic Fermi-Bose mixtures in bichromatic optical dipole traps: a novel route to study fermion superfluidity
The study of low density, ultracold atomic Fermi gases is a promising avenue
to understand fermion superfluidity from first principles. One technique
currently used to bring Fermi gases in the degenerate regime is sympathetic
cooling through a reservoir made of an ultracold Bose gas. We discuss a
proposal for trapping and cooling of two-species Fermi-Bose mixtures into
optical dipole traps made from combinations of laser beams having two different
wavelengths. In these bichromatic traps it is possible, by a proper choice of
the relative laser powers, to selectively trap the two species in such a way
that fermions experience a stronger confinement than bosons. As a consequence,
a deep Fermi degeneracy can be reached having at the same time a softer
degenerate regime for the Bose gas. This leads to an increase in the
sympathetic cooling efficiency and allows for higher precision thermometry of
the Fermi-Bose mixture
Ion transport in macroscopic RF linear traps
Efficient transport of cold atoms or ions is a subject of increasing concern
in many experimental applications reaching from quantum information processing
to frequency metrology. For the scalable quantum computer architectures based
on the shuttling of individual ions, different transport schemes have been
developed, which allow to move single atoms minimizing their energy gain. In
this article we discuss the experimental implementation of the transport of a
three-dimensional ion cloud in a macroscopic linear radiofrequency (RF) trap.
The present work is based on numerical simulations done by molecular dynamics
taking into account a realistic experimental environment. The deformation of
the trapping potential and the spatial extension of the cloud during transport
appears to be the major source of the ion energy gain. The efficiency of
transport in terms of transfer probability and ion number is also discussed
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