3,269 research outputs found

    Orthogonality of Biphoton Polarization States

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    Orthogonality of two-photon polarization states belonging to a single frequency and spatial mode is demonstrated experimentally, in a generalization of the well-known anti-correlation 'dip' experiment.Comment: Submitted to Phys.Rev.Let

    Qutrit state engineering with biphotons

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    The novel experimental realization of three-level optical quantum systems is presented. We use the polarization state of biphotons to generate a specific sequence of states that are used in the extended version of BB84 protocol. We experimentally verify the orthogonality of the basis states and demonstrate the ability to easily switch between them. The tomography procedure is employed to reconstruct the density matrices of generated states.Comment: 5 pages, 4 figures. typos correcte

    Measurement of qutrits

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    We proposed the procedure of measuring the unknown state of the three-level system - the qutrit, which was realized as the arbitrary polarization state of the single-mode biphoton field. This procedure is accomplished for the set of the pure states of qutrits; this set is defined by the properties of SU(2) transformations, that are done by the polarization transformers.Comment: 9 pages, 9 figure

    Experimental investigation of high-energy photon splitting in atomic fields

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    The new data analysis of the experiment, where the photon splitting in the atomic fields has been observed for the first time, is presented. This experiment was performed at the tagged photon beam of the ROKK-1M facility at the VEPP-4M collider. In the energy region of 120-450 MeV, the statistics of 1.61091.6\cdot 10^9 photons incident on the BGO target was collected. About 400 candidates to the photon splitting events were reconstructed. Within the attained experimental accuracy, the experimental results are consistent with the cross section calculated exactly in an atomic field. The predictions obtained in the Born approximation significantly differ from the experimental results.Comment: 11 pages, 6 figures, LaTe

    Polarization ququarts

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    We discuss the concept of polarization states of four-dimensional quantum systems based on frequency non-degenerate biphoton field. Several quantum tomography protocols were developed and implemented for measurement of an arbitrary state of ququart. A simple method that does not rely on interferometric technique is used to generate and measure the sequence of states that can be used for quantum communication purposes.Comment: 13 pages, 10 figure

    ИССЛЕДОВАНИЕ ДИНАМИЧЕСКИХ ПАРАМЕТРОВ ЭЛЕКТРОПРИВОДА НА БАЗЕ ДВИГАТЕЛЯ С КАТЯЩИМСЯ РОТОРОМ

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    Purpose. Development and investigation of a dynamic model of electric drive on the base of the rolling rotor motor (RRM) which reflects the positioning of the actuator of the locking and regulating equipment in time. Methodology. Analytical description of electromagnetic and mechanical processes in the electric drive during the RRM shaft movement by using a system of differential equations. Numerical imitation modeling with the processes visualization in the Matlab environment of the RRM rotor displacement with mechanical load in time. Results. It is shown that the degree of influence of the value of the load inertia on the dynamics of the object obtained by the waveform changes the rotation angle of the rotor and motor speed in time. The degree of influence of the value of the electromagnetic time constant of the dynamics of the positioning of the actuator, and the nature of transients during acceleration and fixing position of the rotor with a predetermined moment of inertia for different values of inductance. The effect of the ratio of electromechanical and electromagnetic time constants of the nature of the transition processes accompanying jog mode angular displacement of the drive shaft on the base of RRM. Originality. The lack of technical means to ensure acceptable accuracy time measurement of angular displacement shaft of the actuator in jog mode offset by using a laser meter which gives the opportunity to assess the adequacy of the dynamic model of the RRM. Practical value. The results of investigations allow to create a tool for optimization of structural, technical and hardware and software solutions for the improvement and modernization of the projected electric locking and regulating equipment. The direction for improving the dynamics of the drive on the basis of RRM is indicated providing for an increase in its torque characteristics of the motor by reducing the influence of the parameters of transients.Анализируются динамические параметры электропривода на базе двигателя с катящимся ротором. Точность позиционирования такого мехатронного модуля обеспечивается в результате исследования факторов, определяющих электромеханическую и электромагнитную постоянные времени. Экспериментальная оценка времени переходного процесса при управлении позиционированием модуля позволяет исследовать влияние различных параметров электропривода на его динамику.Аналізуються динамічні параметри електроприводу на базі двигуна з ротором, що котиться. Точність позиціонування такого мехатронного модуля забезпечуються в результаті дослідження факторів, що визначають електромеханічну та електромагнітну сталі часу. Експериментальна оцінка часу перехідного процесу при керуванні позиціонуванням модуля дозволяє досліджувати вплив різних параметрів електроприводу на його динаміку

    MINERAL AND RAW MATERIALS BASE OF THE URAL FEDERAL DISTRICT: ON THE WAY TO A SUSTAINABLE SUBSOIL USE (USING SOLID COMMERCIAL MINERALS AS AN EXAMPLE)

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    Relevance. The process of sustainable use of mineral resources, which is one of the priority areas of both rehabilitation, extraction of natural resources, and the state policy in the field of national security, is of particular importance. Currently, the state regulation of subsoil use faces a number of pressing problems: first, the process of recovering the exhaustible resources of solid commercial minerals (SCM) is hampered; secondly, penetration the sixth techno-economic paradigm and the growing “fourth industrial revolution” dictate their terms for organizing a sustainable subsoil use, which implies achieving a balance of common development factors (resource, “green”, social, economic ones) using high technologies, artificial intelligence devices, robotics and other innovative solutions. In order to implement sustainable subsoil use at the regional and country levels, it is necessary to diagnose the state of the mineral resources base (MRB). This evaluation can become a functional tool for state regulation of subsoil use. Purpose of the work is to analyze the state of the mineral resource base of the subsoil use of the Ural Federal District (UFD) from the point of view of fulfilling the condition of balance (security). Results. The basic principle is defined – the condition for achieving a balance of subsoil use; peculiarities and problems in the management of subsoil use of the Ural Federal District on the basis of the analysis of the Ural Federal District and the system for financing geological exploration in the UFD; some possible directions for meeting the condition for achieving a balance are identified. Conclusion. The exhaustion of the region’s MRB of SCM and the priority of the extraction of fuel and energy raw materials contribute to a reduction in federal funding for the development of the MRB of SCM of the Ural Federal District. The subsoil users of the region are provided with reserves, to some extent, and they are not interested in carrying out further prospecting works. The foregoing demonstrates the need to develop and implement some balanced solutions for further stage of geological study of the MRB of SCM in the framework of public private partnerships using industry regulation mechanisms to achieve a sustainable supply of producers with their own raw materials
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