6,123 research outputs found
Non-reciprocal few-photon devices based on chiral waveguide-emitter couplings
We demonstrate the possibility of designing efficient, non reciprocal
few-photon devices by exploiting the chiral coupling between two waveguide
modes and a single quantum emitter. We show how this system can induce
non-reciprocal photon transport at the single-photon level and act as an
optical diode. Afterwards, we also show how the same system shows a
transistor-like behaviour for a two-photon input. The efficiency in both cases
is shown to be large for feasible experimental implementations. Our results
illustrate the potential of chiral waveguide-emitter couplings for applications
in quantum circuitry.Comment: Mathematica notebook attached for calculation of detection
probabilitie
Tau anomalous magnetic moment form factor at Super B/Flavor factories
The proposed high-luminosity B/Flavor factories offer new opportunities for
the improved determination of the fundamental physical parameters of standard
heavy leptons. Compared to the electron or the muon case, the magnetic
properties of the lepton are largely unexplored. We show that the
electromagnetic properties of the , and in particular its magnetic form
factor, may be measured competitively in these facilities, using unpolarized or
polarized electron beams. Various observables of the 's produced on top
of the resonances, such as cross-section and normal polarization for
unpolarized electrons or longitudinal and transverse asymmetries for polarized
beams, can be combined in order to increase the sensitivity on the magnetic
moment form factor. In the case of polarized electrons, we identify a special
combination of transverse and longitudinal polarizations able to
disentangle this anomalous magnetic form factor from both the charge form
factor and the interference with the Z-mediating amplitude. For an integrated
luminosity of one could achieve a sensitivity of
about , which is several orders of magnitude below any other existing
high- or low-energy bound on the magnetic moment. Thus one may obtain a QED
test of this fundamental quantity to a few % precision.Comment: 20 pages, 4 figure
Entanglement of two qubits mediated by one-dimensional plasmonic waveguides
We investigate qubit-qubit entanglement mediated by plasmons supported by
one-dimensional waveguides. We explore both the situation of spontaneous
formation of entanglement from an unentangled state and the emergence of driven
steady-state entanglement under continuous pumping. In both cases, we show that
large values for the concurrence are attainable for qubit-qubit distances
larger than the operating wavelength by using plasmonic waveguides that are
currently available.Comment: 4 pages, 4 figures. Minor Changes. Journal Reference added.
Highlighted in Physic
Postmenopausal women with osteoporosis consume high amounts of vegetables but insufficient dairy products and calcium to benefit from their virtues: the CoLaus/OsteoLaus cohort.
We evaluated the associations between nutrients, dietary patterns or compliance to dietary guidelines and bone health among postmenopausal women from the CoLaus/OsteoLaus cohort. Postmenopausal women with osteoporosis consume a high amount of vegetables but insufficient amount of dairy products and calcium to benefit from their adherence to dietary guidelines.
Diet plays a significant role in the prevention of osteoporosis (OP). We evaluated the associations between nutrients, dietary patterns or compliance (expressed in odds of meeting) to dietary Swiss guidelines and bone health (T score < - 2.5 SD, TBS < 1230) among postmenopausal women.
One thousand two hundred fifteen women (64.3 ± 7.5 years) from the CoLaus/OsteoLaus cohort (Lausanne, Switzerland) had their dietary intake assessed using a validated food frequency questionnaire. Bone mineral density (BMD), trabecular bone score (TBS) and vertebral fractures were evaluated with DXA. OP risk factors, calcium supplements (> 500 mg) and prevalent major OP fractures were assessed by questionnaire.
One hundred eighty of 1195 women had OP according to BMD, 87/1185 a low TBS and 141/1215 prevalent major OP fractures. In multivariate analysis (adjusted for total energy intake, age, antiosteoporotic treatment, educational level, BMI, sedentary status and diabetes), OP women consumed more vegetable proteins (21.3 ± 0.4 vs 19.6 ± 0.2 g/day), more fibres (18.2 ± 0.5 vs 16.5 ± 0.2 g/day), less animal proteins (40.0 ± 1.1 vs 42.8 ± 0.4 g/day), less calcium (928 ± 30 vs 1010 ± 12 mg/day) and less dairy products (175 ± 12 vs 215 ± 5 g/day), all p ≤ 0.02. According to guidelines, OP women had a tendency to higher compliance for vegetables (OR (95% CI) 1.50 (0.99-2.26)) and a lower compliance for dairy (OR (95% CI) 0.44 (0.22-0.86)) than those without OP. Women taking calcium supplements consumed significantly higher amounts of dairy products. No association was found between TBS values or prevalent OP fractures and any dietary components.
Postmenopausal women with OP consume a high amount of vegetables but insufficient amount of dairy products and calcium. TBS does not seem to be influenced by diet
Anemia profile in critical septic patients hospitalized in the ICU
This article is part of the supplement: 31st International Symposium on Intensive Care and Emergency MedicineThe aim was to describe the anemia profile of medical or surgical patients with severe sepsis or septic shock in the ICU, assessing severity scale, length of stay and mortality. The prevalence of microcytic anemia is more than one-half of our septic patients. There are iron metabolism disorders without significant differences between medical and surgical patients. Transferrin, a protein related to malnutrition, inflammatory response and organ dysfunction, is significantly lower in the most severe patients with higher organ dysfunction scores.Ye
Elodie metallicity-biased search for transiting Hot Jupiters IV. Intermediate period planets orbiting the stars HD43691 and HD132406
We report here the discovery of two planet candidates as a result of our
planet-search programme biased in favour of high-metallicity stars, using the
ELODIE spectrograph at the Observatoire de Haute Provence. One of them has a
minimum mass m_2\sin{i} = 2.5 M_Jup and is orbiting the metal-rich star HD43691
with period P = 40 days and eccentricity e = 0.14. The other planet has a
minimum mass m_2\sin{i} = 5.6 M_Jup and orbits the slightly metal-rich star
HD132406 with period P = 974 days and eccentricity e = 0.34. Both stars were
followed up with additional observations using the new SOPHIE spectrograph that
replaces the ELODIE instrument, allowing an improved orbital solution for the
systems.Comment: 6 pages, 4 figures, to be published in A&
Interstellar abundances in the neutral and ionized gas of NGC604
We present FUSE spectra of the giant HII region NGC604 in the spiral galaxy
M33. Chemical abundances are derived from far-UV absorption lines and are
compared to those derived from optical emission lines. We derived the column
densities of HI, NI, OI, SiII, PII, ArI, and FeII, fitting the line profiles
with either a single component or several components. Our net results, assuming
a single component, show that N, O, Si, and Ar are apparently underabundant in
the neutral phase by a factor of 10 or more with respect to the ionized phase,
while Fe is the same. However, we discuss the possibility that the absorption
lines are made of individual unresolved components, and find that only PII,
ArI, and FeII lines should not be affected by the presence of hidden saturated
components, while NI, OI, and SiII might be much more affected. If N, O, and Si
are actually underabundant in the neutral gas of NGC604 with respect to the
ionized gas, this would confirm earlier results obtained for the blue compact
dwarfs. However, a deeper analysis focused on P, Ar, and Fe mitigates the above
conclusion and indicates that the neutral gas and ionized gas could have
similar abundances.Comment: Accepted for publication in A&
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