4,081 research outputs found

    Polarization entangled state measurement on a chip

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    The emerging strategy to overcome the limitations of bulk quantum optics consists of taking advantage of the robustness and compactness achievable by the integrated waveguide technology. Here we report the realization of a directional coupler, fabricated by femtosecond laser waveguide writing, acting as an integrated beam splitter able to support polarization encoded qubits. This maskless and single step technique allows to realize circular transverse waveguide profiles able to support the propagation of Gaussian modes with any polarization state. Using this device, we demonstrate the quantum interference with polarization entangled states and singlet state projection.Comment: Revtex, 5+2 pages (with supplementary information), 4+1 figure

    Universal computation by multi-particle quantum walk

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    A quantum walk is a time-homogeneous quantum-mechanical process on a graph defined by analogy to classical random walk. The quantum walker is a particle that moves from a given vertex to adjacent vertices in quantum superposition. Here we consider a generalization of quantum walk to systems with more than one walker. A continuous-time multi-particle quantum walk is generated by a time-independent Hamiltonian with a term corresponding to a single-particle quantum walk for each particle, along with an interaction term. Multi-particle quantum walk includes a broad class of interacting many-body systems such as the Bose-Hubbard model and systems of fermions or distinguishable particles with nearest-neighbor interactions. We show that multi-particle quantum walk is capable of universal quantum computation. Since it is also possible to efficiently simulate a multi-particle quantum walk of the type we consider using a universal quantum computer, this model exactly captures the power of quantum computation. In principle our construction could be used as an architecture for building a scalable quantum computer with no need for time-dependent control

    The level width of atomic nuclei in the continuum energy region: Comparison with the statistical-model previsions

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    In this paper the theoretical expression of the « coherence energy » which characterizes the Ericson flctuations of an excitation function is derived in the framework of the statistical model. It is given by a weighted average over spins, parity and energy of the widths of the levels of the compound nucleus interested in the reaction. The case of purely statistical reactions and the case in which a nonstatistical effect is present are analised

    Experimental study of Pomeron

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    A Pomeron phenomenon remains a mystery. A short review of the experimental situation in diffractive physics and an account of some spectacular manifestations of the Pomeron are given.Comment: 17 pages, 7 Figs, LATEX. Talk given at the conference "From the smallest to largest distances", ITEP, Moscow, 24-26 May 2001. Changes: Fig.2 replace

    General rules for bosonic bunching in multimode interferometers

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    We perform a comprehensive set of experiments that characterize bosonic bunching of up to 3 photons in interferometers of up to 16 modes. Our experiments verify two rules that govern bosonic bunching. The first rule, obtained recently in [1,2], predicts the average behavior of the bunching probability and is known as the bosonic birthday paradox. The second rule is new, and establishes a n!-factor quantum enhancement for the probability that all n bosons bunch in a single output mode, with respect to the case of distinguishable bosons. Besides its fundamental importance in phenomena such as Bose-Einstein condensation, bosonic bunching can be exploited in applications such as linear optical quantum computing and quantum-enhanced metrology.Comment: 6 pages, 4 figures, and supplementary material (4 pages, 1 figure

    A comparison of audio-based deep learning methods for detecting anomalous road events

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    Road surveillance systems have an important role in monitoring roads and safeguarding their users. Many of these systems are based on video streams acquired from urban video surveillance infrastructures, from which it is possible to reconstruct the dynamics of accidents and detect other events. However, such systems may lack accuracy in adverse environmental settings: for instance, poor lighting, weather conditions, and occlusions can reduce the effectiveness of the automatic detection and consequently increase the rate of false or missed alarms. These issues can be mitigated by integrating such solutions with audio analysis modules, that can improve the ability to recognize distinctive events such as car crashes. For this purpose, in this work we propose a preliminary analysis of solutions based on Deep Learning techniques for the automatic identification of hazardous events through the analysis of audio spectrograms

    Engineering a C-Phase quantum gate: optical design and experimental realization

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    A two qubit quantum gate, namely the C-Phase, has been realized by exploiting the longitudinal momentum (i.e. the optical path) degree of freedom of a single photon. The experimental setup used to engineer this quantum gate represents an advanced version of the high stability closed-loop interferometric setup adopted to generate and characterize 2-photon 4-qubit Phased Dicke states. Some experimental results, dealing with the characterization of multipartite entanglement of the Phased Dicke states are also discussed in detail.Comment: accepted for publication on EPJ

    Evaluation of the disciplinary competences of the students of the Bachelor's degree in Nursing at 'Sapienza' University of Rome through the TECO: A cross-sectional study

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    The objective of the study is to evaluate whether the TECO-D is a useful tool for measuring the skills acquired by students during three years of the nursing bachelor's degree course at the 'Sapienza' University of Rome. The sample was recruited between January and April 2018. The distribution of the scores for the TECO-D shows an increasing average (standard deviation) from 177.3 ± 28 in the first year up to 214.1 ± 18.5 for graduating students. The test is comprehensive by sampling all relevant disciplines in a curriculum, usually determined by a fixed blueprint. The evaluation of the single macro areas showed statistically significant data reflecting increasing knowledge regarding the progression of the skills. Because of this, we can say that the TECO-D is a great tool for determining student's knowledge in order to evaluate study programs

    eHealth literacy scale: a nursing analysis and Italian validation

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    Background: One of the scales most used to measure quickly and easily eHealth Literacy is the eHealth LiteracyScale (eHEALS); however, there was no validation of this scale in Italian. Therefore, the aim of this study was to adapt and validate the eHealth Literacy Scale (eHEALS) to the italian context. Methods: Italian translation of eHEALS was administered along unit to another two scale for measure lifestyle habits self-esteem and life satisfaction). A sample of 650 university students aged between 18 and 45 years was selected. An exploratory factor analysis, confirmatory factor analysis, analysis of invariance, reliability, stability and bivariate correlations were performed. Results: Exploratory factor analysis revealed a monofactorial structure that explained 67% of variance. Reliability of 0.87 and test-retest correlation of 0.78 was obtained. The questionnaire was invariant by gender. Regarding the criterion validity, a statistically significant and positive correlations between 0.05 and 0.15 with three indicators was obtained (self-esteem, lifestyle habits and life satisfaction). The italian version of the eHEALS tested in this work has shown to be a valid and reliable scale to measure eHealth competence in university students
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