553 research outputs found
Macroscopic Observables Detecting Genuine Multipartite Entanglement and Partial Inseparability in Many-Body Systems
We show a general approach for detecting genuine multipartite entanglement
(GME) and partial inseparability in many-body-systems by means of macroscopic
observables (such as the energy) only. We show that the obtained criteria, the
"GME gap" and "the k-entanglement gap", detect large areas of genuine
multipartite entanglement and partial entanglement in typical many body states,
which are not detected by other criteria. As genuine multipartite entanglement
is a necessary property for several quantum information theoretic applications
such as e.g. secret sharing or certain kinds of quantum computation, our
methods can be used to select or design appropriate condensed matter systems.Comment: 4 pages, 3 figures, published version, title extende
Fractal diffusion coefficient from dynamical zeta functions
Dynamical zeta functions provide a powerful method to analyze low dimensional
dynamical systems when the underlying symbolic dynamics is under control. On
the other hand even simple one dimensional maps can show an intricate structure
of the grammar rules that may lead to a non smooth dependence of global
observable on parameters changes. A paradigmatic example is the fractal
diffusion coefficient arising in a simple piecewise linear one dimensional map
of the real line. Using the Baladi-Ruelle generalization of the
Milnor-Thurnston kneading determinant we provide the exact dynamical zeta
function for such a map and compute the diffusion coefficient from its smallest
zero.Comment: 8 pages, 2 figure
Deep Electrical Resistivity Tomography for the Hydrogeological Setting of Muro Lucano Mounts Aquifer (Basilicata, Southern Italy)
The proposed work concerns the application of a deep geoelectrical survey to a carbonate aquifer in order to define the best location for exploitation well drilling for increasing water supply. However, an optimal characterization of a groundwater resource is the necessary condition to reach the indicated aim. Therefore, the geoelectrical investigation was guided from the previous geological and hydrogeological characterization. Moreover, geophysical methods are good tools to improve the groundwater model when detailed information is necessary, such as the localization of a pumping well. The work summarizes the hydrogeological knowledge at the West of the Basilicata Region (Muro Lucano, Italy). The investigated area is characterized by the presence of a karst aquifer which is made up of a carbonate ridge (Castelgrande, Muro Lucano) that tectonically dips southward and is widely covered by Pliocene deposits (sands and conglomerates), by the Irpinian unit and Sicilide unit formations, and by debris slope and landslide deposits. The assessment of the complex hydrogeological framework of the area was detailed by the use of a new multichannel deep geoelectrical technique (DERT). In details, the proposed technique was able to successfully locate a less resistive zone connected to a more fractured limestone and then it was suitable for the localization of a groundwater exploitation well
Mixtures of strongly interacting bosons in optical lattices
We investigate the properties of strongly interacting heteronuclear
boson-boson mixtures loaded in realistic optical lattices, with particular
emphasis on the physics of interfaces. In particular, we numerically reproduce
the recent experimental observation that the addition of a small fraction of K
induces a significant loss of coherence in Rb, providing a simple explanation.
We then investigate the robustness against the inhomogeneity typical of
realistic experimental realizations of the glassy quantum emulsions recently
predicted to occur in strongly interacting boson-boson mixtures on ideal
homogeneous lattices.Comment: 10 pages, 3 figures; some changes in the text and abstract have been
introduced; coherence now given in terms of visibility; a couple of new
reference adde
Unconventional quantum phases of lattice bosonic mixtures
We consider strongly interacting boson-boson mixtures on one-dimensional
lattices and, by adopting a qualitative mean-field approach, investigate their
quantum phases as the interspecies repulsion is increased. In particular, we
analyze the low-energy "quantum emulsion" metastable states occurring at large
values of the interspecies interaction, which are expected to prevent the
system from reaching its true ground state. We argue a significant decrease in
the visibility of the time-of-flight images in the case of these spontaneously
disordered states.Comment: 10 pages, 2 figures - to appear in the topical issue on "Novel
Quantum Phases and Mesoscopic Physics in Quantum Gases" of the European
Physical Journal B (2009
Correlations and charge distributions of medium heavy nuclei
The effects of long- and short-range correlations on the charge distributions
of some medium and heavy nuclei are investigated. The long-range correlations
are treated within the Random Phase Approximation framework and the short-range
correlations with a model inspired to the Correlation Basis Function theory.
The two type of correlations produce effects of the same order of magnitude. A
comparison with the empirical charge distribution difference between 206Pb and
205Tl shows the need of including both correlations to obtain a good
description of the data.Comment: 20 pages, Latex, accepted for publication in Jour. Phys.
Multipartite Entanglement and Frustration
Some features of the global entanglement of a composed quantum system can be
quantified in terms of the purity of a balanced bipartition, made up of half of
its subsystems. For the given bipartition, purity can always be minimized by
taking a suitable (pure) state. When many bipartitions are considered, the
requirement that purity be minimal for all bipartitions can engender conflicts
and frustration arises. This unearths an interesting link between frustration
and multipartite entanglement, defined as the average purity over all
(balanced) bipartitions.Comment: 15 pages, 7 figure
Outpatient parents' views on shared-decision-making at an Italian children's hospital
Information is lacking on what parents in southern European countries know and how they view clinical shared-decision-making (SDM) for their children. This survey assesses general parental views on SDM and patient-physician SDM relationships in an Italian paediatric outpatients' clinic. In a 3-month cross-sectional survey, we enrolled 458 consecutive native and foreign Italian-speaking parents bringing their children to our public hospital for various reasons. Parents completed an anonymous questionnaire exploring their general views on SDM, including what doctor-patient relationship predominates today, and what approach reassures them most. Multivariate logistic regression analysed outcome data from parental questionnaire answers. Results are reported as percentages, odds ratios (OR) and 95% confidence intervals (CI). Multivariate logistic regression showed that 440 parents (96.1%) appreciated SDM, 245 (53.5%) preferred SDM for choosing children's treatment, 126 (27.5%) answered that SDM is the predominant relationship today, and most parents 275 (60.0%) felt reassured by SDM. More native than foreign Italian-speaking parents preferred SDM (97.0 vs 89.7%, OR = 3.8; 95% CI = 1.4-10.8). Highly-educated parents preferred SDM for choosing their child's therapy (57.9 vs 34.1%, OR = 2.7; 95% CI = 1.6-4.4) and this approach reassured them (64.3 vs 41.2%, OR = 2.5; 95% CI = 1.6-4.1). In conclusion, parents bringing children to an Italian outpatient clinic, especially highly-educated parents, wish to be offered SDM and find it reassuring. These findings should encourage paediatricians working in a challenging multicultural environment to change their physician-centred approach and engage parents in tailored SDM strategies
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