8,432 research outputs found

    Multiparticle Quantum Superposition and Stimulated Entanglement by Parity Selective Amplification of Entangled States

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    A multiparticle quantum superposition state has been generated by a novel phase-selective parametric amplifier of an entangled two-photon state. This realization is expected to open a new field of investigations on the persistence of the validity of the standard quantum theory for systems of increasing complexity, in a quasi decoherence-free environment. Because of its nonlocal structure the new system is expected to play a relevant role in the modern endeavor on quantum information and in the basic physics of entanglement.Comment: 13 pages and 3 figure

    Separating the classical and quantum information via quantum cloning

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    An application of quantum cloning to optimally interface a quantum system with a classical observer is presented, in particular we describe a procedure to perform a minimal disturbance measurement on a single qubit by adopting a 1->2 cloning machine followed by a generalized measurement on a single clone and the anti-clone or on the two clones. Such scheme has been applied to enhance the transmission fidelity over a lossy quantum channel.Comment: 4 pages, 2figure

    Continuous variable cloning via network of parametric gates

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    We propose an experimental scheme for the cloning machine of continuous quantum variables through a network of parametric amplifiers working as input-output four-port gates.Comment: 4 pages, 2 figures. To appear on Phys. Rev. Let

    Complete and Deterministic discrimination of polarization Bell state assisted by momentum entanglement

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    A complete and deterministic Bell state measurement was realized by a simple linear optics experimental scheme which adopts 2-photon polarization-momentum hyperentanglement. The scheme, which is based on the discrimination among the single photon Bell states of the hyperentangled state, requires the adoption of standard single photon detectors. The four polarization Bell states have been measured with average fidelity F=0.889±0.010F=0.889\pm0.010 by using the linear momentum degree of freedom as the ancilla. The feasibility of the scheme has been characterized as a function of the purity of momentum entanglement.Comment: 4 pages, v2, comments adde

    Analytical modeling of the structureborne noise path on a small twin-engine aircraft

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    The structureborne noise path of a six passenger twin-engine aircraft is analyzed. Models of the wing and fuselage structures as well as the interior acoustic space of the cabin are developed and used to evaluate sensitivity to structural and acoustic parameters. Different modeling approaches are used to examine aspects of the structureborne path. These approaches are guided by a number of considerations including the geometry of the structures, the frequency range of interest, and the tractability of the computations. Results of these approaches are compared with experimental data

    Experimental Purification of Single Qubits

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    We report the experimental realization of the purification protocol for single qubits sent through a depolarization channel. The qubits are associated with polarization encoded photon particles and the protocol is achieved by means of passive linear optical elements. The present approach may represent a convenient alternative to the distillation and error correction protocols of quantum information.Comment: 10 pages, 2 figure

    "All-versus-nothing" nonlocality test of quantum mechanics by two-photon hyperentanglement

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    We report the experimental realization and the characterization of polarization and momentum hyperentangled two photon states, generated by a new parametric source of correlated photon pairs. By adoption of these states an "all versus nothing" test of quantum mechanics was performed. The two photon hyperentangled states are expected to find at an increasing rate a widespread application in state engineering and quantum information. PACS: 03.65.Ud, 03.67.Mn, 42.65. LmComment: Replaced with published versio

    Effect of atomic beam alignment on photon correlation measurements in cavity QED

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    Quantum trajectory simulations of a cavity QED system comprising an atomic beam traversing a standing-wave cavity are carried out. The delayed photon coincident rate for forwards scattering is computed and compared with the measurements of Rempe et al. [Phys. Rev. Lett. 67, 1727 (1991)] and Foster et al. [Phys. Rev. A 61, 053821 (2000)]. It is shown that a moderate atomic beam misalignment can account for the degradation of the predicted correlation. Fits to the experimental data are made in the weak-field limit with a single adjustable parameter--the atomic beam tilt from perpendicular to the cavity axis. Departures of the measurement conditions from the weak-field limit are discussed.Comment: 15 pages and 13 figure

    Introduction

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    Psychiatry is the branch of medicine appointed to the diagnosis, treatment, and prevention of mental disorders. Throughout ages, the concept of mental illness had changed many times, and today, the biopsychosocial model tries to explain mental disorders as the result of the complex interaction between biological correlates, psychological factors, and the socio-cultural background. The psychiatric interview is the fundamental element for the evaluation of the subject with mental illness. It allows to have access to the patient’s psychic state, enabling to collect the information that will guide the professional in formulating a diagnosis and through the choice of therapy
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