2,137 research outputs found

    Quantal Two-Centre Coulomb Problem treated by means of the Phase-Integral Method II. Quantization Conditions in the Symmetric Case Expressed in Terms of Complete Elliptic Integrals. Numerical Illustration

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    The contour integrals, occurring in the arbitrary-order phase-integral quantization conditions given in a previous paper, are in the first- and third-order approximations expressed in terms of complete elliptic integrals in the case that the charges of the Coulomb centres are equal. The evaluation of the integrals is facilitated by the knowledge of quasiclassical dynamics. The resulting quantization conditions involving complete elliptic integrals are solved numerically to obtain the energy eigenvalues and the separation constants of the 1sσ1s\sigma and 2pσ2p\sigma states of the hydrogen molecule ion for various values of the internuclear distance. The accuracy of the formulas obtained is illustrated by comparison with available numerically exact results.Comment: 19 pages, RevTeX 4, 4 EPS figures, submitted to J. Math. Phy

    Plasma-deposited aluminum-doped zinc oxide : controlling nucleation, growth and electrical properties

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    In this work, the Expanding Thermal Plasma (ETP) deposition technique was employed to study the growth development of ZnO:Al thin film as a transparent conductive oxide layer for sustainable applications. Characteristic for ETP-grown ZnO:Al is a gradually reducing resistivity of the growing layer with increase in the layer thickness, so-called resistivity gradient, due to the gradually increasing grain size and mobility of the electrons. Therefore, structural development is studied in relationship with the electrical and optical properties of the films. Several possibilities are shown to improve the ZnO:Al properties. For example, passivation of grain boundary scattering centers is demonstrated upon capping ZnO:Al films with a-Si:H and subsequent high temperature treatment. Another approach achieved reduction of the resistivity gradient by formation of compact nucleation layer with a large grain size and multiple crystal orientations. That lead to achievement of resistivity as low as 3.9•10-4 O•cm at significantly lower thickness of 300 nm, compared to 700 nm for the reference film. Furthermore, the plasma processes leading to this improvement are studied in detail and a possible growth mechanism is proposed. Finally, the effect of improved nucleation of ZnO:Al grains is studied by using small (3-5 nm in diameter) silver nanoparticles deposited prior ZnO:Al growth. The silver nanoparticles act as an epitaxial template, also causing reduction of void inclusion throughout the film thickness and reduced as a factor of 2 resistivity in the thickness range up to 1100 nm

    Double giant resonances in deformed nuclei

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    We report on the first microscopic study of the properties of two-phonon giant resonances in deformed nuclei. The cross sections of the excitation of the giant dipole and the double giant dipole resonances in relativistic heavy ion collisions are calculated. We predict that the double giant dipole resonance has a one-bump structure with a centroid 0.8 MeV higher than twice energy for the single giant dipole resonance in the reaction under consideration. The width of the double resonance equals to 1.33 of that for the single resonance.Comment: 5 pages, 2 postscript figure

    Theoretical and methodological grounds for the modernization of the tax administration system

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    The article stands for the theoretical underpinning of economic grounds of tax system and its building on the basis of social- and business-oriented socioeconomic features. Authors proved the need for tax process management that represent the features of government-society-taxpayer relations with taxpayer’s leading role as macroeconomic tool for economic regulation process as well as providing the sustainable and balanced economic growth and innovative modernization of Russian economy.peer-reviewe

    Self-consistent approach for the quantum confined Stark effect in shallow quantum wells

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    A computationally efficient, self-consistent complex scaling approach to calculating characteristics of excitons in an external electric field in quantum wells is introduced. The method allows one to extract the resonance position as well as the field-induced broadening for the exciton resonance. For the case of strong confinement the trial function is represented in factorized form. The corresponding coupled self-consistent equations, which include the effective complex potentials, are obtained. The method is applied to the shallow quantum well. It is shown that in this case the real part of the effective exciton potential is insensitive to changes of external electric field up to the ionization threshold, while the imaginary part has non-analytical field dependence and small for moderate electric fields. This allows one to express the exciton quasi-energy at some field through the renormalized expression for the zero-field bound state.Comment: 13 pages, RevTeX4, 6 figure

    Calculations of exchange interaction in impurity band of two-dimensional semiconductors with out of plane impurities

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    We calculate the singlet-triplet splitting for a couple of two-dimensional electrons in the potential of two positively charged impurities which are located out of plane. We consider different relations between vertical distances of impurities h1h_1 and h2h_2 and their lateral distance RR. Such a system has never been studied in atomic physics but the methods, worked out for regular two-atomic molecules and helium atom, have been found to be useful. Analytical expressions for several different limiting configurations of impurities are obtained an interpolated formula for intermediate range of parameters is proposed. The RR-dependence of the splitting is shown to become weaker with increasing h1,h2h_1,h_2.Comment: 14 pages, RevTeX, 5 figures. Submitted to Phys Rev.
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