28,819 research outputs found
Dynamics of small trapped one-dimensional Fermi gas under oscillating magnetic fields
Deterministic preparation of an ultracold harmonically trapped
one-dimensional Fermi gas consisting of a few fermions has been realized by the
Heidelberg group. Using Floquet formalism, we study the time dynamics of two-
and three-fermion systems in a harmonic trap under an oscillating magnetic
field. The oscillating magnetic field produces a time-dependent interaction
strength through a Feshbach resonance. We explore the dependence of these
dynamics on the frequency of the oscillating magnetic field for
non-interacting, weakly interacting, and strongly interacting systems. We
identify the regimes where the system can be described by an effective
two-state model and an effective three-state model. We find an unbounded
coupling to all excited states at the infinitely strong interaction limit and
several simple relations that characterize the dynamics. Based on our findings,
we propose a technique for driving transition from the ground state to the
excited states using an oscillating magnetic field.Comment: 11 pages, 7 figure
Generating EPR beams in a cavity optomechanical system
We propose a scheme to produce continuous variable entanglement between
phase-quadrature amplitudes of two light modes in an optomechanical system. For
proper driving power and detuning, the entanglement is insensitive with bath
temperature and of mechanical oscillator. Under realistic experimental
conditions, we find that the entanglement could be very large even at room
temperature.Comment: 4.1 pages, 4 figures, comments are welcome; to appear in PRA,
published version with corrections of typo
Matching model of flow table for networked big data
Networking for big data has to be intelligent because it will adjust data
transmission requirements adaptively during data splitting and merging.
Software-defined networking (SDN) provides a workable and practical paradigm
for designing more efficient and flexible networks. Matching strategy in the
flow table of SDN switches is most crucial. In this paper, we use a
classification approach to analyze the structure of packets based on the
tuple-space lookup mechanism, and propose a matching model of the flow table in
SDN switches by classifying packets based on a set of fields, which is called
an F-OpenFlow. The experiment results show that the proposed F-OpenFlow
effectively improves the utilization rate and matching efficiency of the flow
table in SDN switches for networked big data.Comment: 14 pages, 6 figures, 2 table
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