311 research outputs found
Adiabatic loading of a Bose-Einstein condensate in a 3D optical lattice
We experimentally investigate the adiabatic loading of a Bose-Einstein
condensate into an optical lattice potential. The generation of excitations
during the ramp is detected by a corresponding decrease in the visibility of
the interference pattern observed after free expansion of the cloud. We focus
on the superfluid regime, where we show that the limiting time scale is related
to the redistribution of atoms across the lattice by single-particle tunneling
Guidelines for the Definition of Innovative Industrial Product-service Systems (PSS) Business Models for Remanufacturing
AbstractRemanufacturing represents a well-suited approach for sustainable development in environmental, economic and social dimensions. Product-service systems (PSS) are among the most important enabler for remanufacturing. Companies that remain owner of a product have an intrinsic motivation to design goods for longer lifecycles considering the possibility of remanufacturing the product or its parts after each use phase. In addition, as the end customer only uses the goods without having its ownership, the acceptance – and consequently the demand – for remanufactured goods is significantly improved. This paper presents guidelines for the definition of innovative business models for remanufacturing, utilizing both remanufacturing and PSS characteristics, and permitting the dissemination of knowledge needed for successful implementation within a company strategy and operations model. Focusing on industrial PSS, an illustrative application of the guidelines is demonstrated
Fictitious Magnetic Resonance by Quasi-Electrostatic Field
We propose a new kind of spin manipulation method using a {\it fictitious}
magnetic field generated by a quasi-electrostatic field. The method can be
applicable to every atom with electron spins and has distinct advantages of
small photon scattering rate and local addressability. By using a
laser as a quasi-electrostatic field, we have experimentally demonstrated the
proposed method by observing the Rabi-oscillation of the ground state hyperfine
spin F=1 of the cold atoms and the Bose-Einstein condensate.Comment: 5 pages, 5 figure
Precision measurement of spin-dependent interaction strengths for spin-1 and spin-2 87Rb atoms
We report on precision measurements of spin-dependent interaction-strengths
in the 87Rb spin-1 and spin-2 hyperfine ground states. Our method is based on
the recent observation of coherence in the collisionally driven spin-dynamics
of ultracold atom pairs trapped in optical lattices. Analysis of the Rabi-type
oscillations between two spin states of an atom pair allows a direct
determination of the coupling parameters in the interaction hamiltonian. We
deduce differences in scattering lengths from our data that can directly be
compared to theoretical predictions in order to test interatomic potentials.
Our measurements agree with the predictions within 20%. The knowledge of these
coupling parameters allows one to determine the nature of the magnetic ground
state. Our data imply a ferromagnetic ground state for 87Rb in the f=1
manifold, in agreement with earlier experiments performed without the optical
lattice. For 87Rb in the f=2 manifold the data points towards an
antiferromagnetic ground state, however our error bars do not exclude a
possible cyclic phase.Comment: 11 pages, 5 figure
Quantum jumps and spin dynamics of interacting atoms in a strongly coupled atom-cavity system
We experimentally investigate the spin dynamics of one and two neutral atoms
strongly coupled to a high finesse optical cavity. We observe quantum jumps
between hyperfine ground states of a single atom. The interaction-induced
normal mode splitting of the atom-cavity system is measured via the atomic
excitation. Moreover, we observe evidence for conditional dynamics of two atoms
simultaneously coupled to the cavity mode. Our results point towards the
realization of measurement-induced entanglement schemes for neutral atoms in
optical cavities.Comment: 4 pages, 4 figures, published versio
Excitations in two-component Bose-gases
In this paper, we study a strongly correlated quantum system that has become
amenable to experiment by the advent of ultracold bosonic atoms in optical
lattices, a chain of two different bosonic constituents. Excitations in this
system are first considered within the framework of bosonization and Luttinger
liquid theory which are applicable if the Luttinger liquid parameters are
determined numerically. The occurrence of a bosonic counterpart of fermionic
spin-charge separation is signalled by a characteristic two-peak structure in
the spectral functions found by dynamical DMRG in good agreement with
analytical predictions. Experimentally, single-particle excitations as probed
by spectral functions are currently not accessible in cold atoms. We therefore
consider the modifications needed for current experiments, namely the
investigation of the real-time evolution of density perturbations instead of
single particle excitations, a slight inequivalence between the two
intraspecies interactions in actual experiments, and the presence of a
confining trap potential. Using time-dependent DMRG we show that only
quantitative modifications occur. With an eye to the simulation of strongly
correlated quantum systems far from equilibrium we detect a strong dependence
of the time-evolution of entanglement entropy on the initial perturbation,
signalling limitations to current reasonings on entanglement growth in
many-body systems
Self-rated treatment outcomes in medical rehabilitation among German and non-German nationals residing in Germany: an exploratory cross-sectional study
Brzoska P, Sauzet O, Yilmaz-Aslan Y, Widera T, Razum O. Self-rated treatment outcomes in medical rehabilitation among German and non-German nationals residing in Germany: an exploratory cross-sectional study. BMC HEALTH SERVICES RESEARCH. 2016;16(1): 105.Background: In many European countries, foreign nationals experience, on average, less favorable treatment outcomes in rehabilitative care than the respective majority population. In Germany, this for example is reflected in a lower occupational performance and a higher risk of disability retirement after rehabilitation as analyses of routine data show. However, little is known about the perspective of health care users. The aim of the present study was to compare self-rated treatment outcomes between German and non-German nationals undergoing in-patient medical rehabilitation in Germany. Methods: We analyzed data from a cross-sectional representative rehabilitation patient survey of 239,811 patients from 642 clinics in Germany who completed about 3 weeks of in-patient rehabilitative treatment. The self-rating of the treatment outcome was based on a dichotomized Likert scale consisting of three items. A multilevel logistic regression analysis adjusted for various demographic, socio-economic, health and other covariates was conducted to examine differences in the self-rated treatment outcome between German and non-German nationals. Results: Of the 239,811 respondents 0.9 % were nationals from Turkey, 0.8 % had a nationality from a former Yugoslavian country, 0.9 % held a nationality from the South European countries Portugal, Spain, Italy or Greece and 1.9 % were nationals from other countries. Non-German nationals reported a less favorable self-rated outcome than Germans. Adjusted odds ratios [OR] for reporting a less favorable treatment outcome were 1.24 (95 %-confidence interval [95 %-CI]: 1.12-1.37) for nationals from the South European countries Portugal/Spain/Italy/Greece, 1.62 (95 %-CI: 1.45-1.80) for Turkish nationals and 1.68 (95 %-CI: 1.52-1.85) for nationals from Former Yugoslavia. Conclusions: Knowledge on health outcomes from the patients' point of view is important for the provision of patient-centered health care. Our study showed that non-German nationals report less favorable outcomes of rehabilitative care than Germans. This may be due to cultural and religious needs not sufficiently addressed by health care providers. In order to improve rehabilitative care for non-German nationals, rehabilitative services must become sensitive to the needs of this population group. Diversity management can contribute to this process
Cooling toolbox for atoms in optical lattices
We propose and analyze several schemes for cooling bosonic and fermionic
atoms in an optical lattice potential close to the ground state of the
no-tunnelling regime. Some of the protocols rely on the concept of algorithmic
cooling, which combines occupation number filtering with ideas from ensemble
quantum computation. We also design algorithms that create an ensemble of
defect-free quantum registers. We study the efficiency of our protocols for
realistic temperatures and in the presence of a harmonic confinement. We also
propose an incoherent physical implementation of filtering which can be
operated in a continuous way.Comment: 14 pages, 13 figure
Multicomponent Bright Solitons in F = 2 Spinor Bose-Einstein Condensates
We study soliton solutions for the Gross--Pitaevskii equation of the spinor
Bose--Einstein condensates with hyperfine spin F=2 in one-dimension. Analyses
are made in two ways: by assuming single-mode amplitudes and by generalizing
Hirota's direct method for multi-components. We obtain one-solitons of
single-peak type in the ferromagnetic, polar and cyclic states, respectively.
Moreover, twin-peak type solitons both in the ferromagnetic and the polar state
are found.Comment: 15 pages, 8 figure
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