206 research outputs found
Multiple scattering and attenuation corrections in Deep Inelastic Neutron Scattering experiments
Multiple scattering and attenuation corrections in Deep Inelastic Neutron
Scattering experiments are analyzed. The theoretical basis is stated, and a
Monte Carlo procedure to perform the calculation is presented. The results are
compared with experimental data. The importance of the accuracy in the
description of the experimental parameters is tested, and the implications of
the present results on the data analysis procedures is examined.Comment: 19 pages, 8 figure
Effects of three-body collisions in a two-mode Bose-Einstein condenstate
We study the effects of three-body collisions in the basic physical
properties of a two-mode Bose-Einstein condensate. By finding the exact
analytical solution of a model which includes two-body and three-body elastic
and mode-exchange collisions, we show analytically that three-body interactions
produce observable effects in the probability distribution of the ground state
and the dynamics of the relative population. In particular, we find that
three-body interactions under certain circumstances inhibit collapse of the
relative population.Comment: 5 pages, 3 figures. I.F. previously published as I. Fuentes-Schuller
and I. Fuentes-Guridi. v2:minor changes, published versio
Feedback in a cavity QED system for control of quantum beats
Conditional measurements on the undriven mode of a two-mode cavity QED system
prepare a coherent superposition of ground states which generate quantum beats.
The continuous system drive induces decoherence through the phase interruptions
from Rayleigh scattering, which manifests as a decrease of the beat amplitude
and an increase of the frequency of oscillation. We report recent experiments
that implement a simple feedback mechanism to protect the quantum beat. We
continuously drive the system until a photon is detected, heralding the
presence of a coherent superposition. We then turn off the drive and let the
superposition evolve in the dark, protecting it against decoherence. At a later
time we reinstate the drive to measure the amplitude, phase, and frequency of
the beats. The amplitude can increase by more than fifty percent, while the
frequency is unchanged by the feedback.Comment: 13 pages, 5 figures, ICAP 2012 23rd International Conference on
Atomic Physic
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