67 research outputs found

    Commercialization of university innovative developments: a retrospective analysis of theoretical approaches to research

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    This study discusses a brief summary of a retrospective content analysis of scientific literature related to the commercialization of university scientists innovative development

    Reflection Symmetry and Quantized Hall Resistivity near Quantum Hall Transition

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    We present a direct numerical evidence for reflection symmetry of longitudinal resistivity ρxx\rho_{xx} and quantized Hall resistivity ρxy\rho_{xy} near the transition between ν=1\nu=1 quantum Hall state and insulator, in accord with the recent experiments. Our results show that a universal scaling behavior of conductances, σxx\sigma_{xx} and σxy\sigma_{xy}, in the transition regime decide the reflection symmetry of ρxx\rho_{xx} and quantization of ρxy\rho_{xy}, independent of particle-hole symmetry. We also find that in insulating phase away from the transition region ρxy\rho_{xy} deviates from the quantization and diverges with ρxx\rho_{xx}.Comment: 3 pages, 4 figures; figure 4 is replace

    Estimation of Innovative Activity of the University

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    On the basis of Belgorod region innovation activity analysis, positive relationship between shipped innovation items and domestic research and development costs was found. Semantic differential was used for multiple estimation of BelSU innovation activity and competiveness. BelSU integrated index showed high-enough innovation activity of this universityyesBelgorod State Universit

    Virality of medical content in Russian social media

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    The work objective is to conduct a sociological study aimed at assessing validity (appropriateness) of the traditional characteristics and formation of a pool of specialized characteristics of the viral content, used in the promotion of health services by means of social media marketin

    Instability of charge ordered states in doped antiferromagnets

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    We analyze the induced interactions between localized holes in weakly-doped Heisenberg antiferromagnets due to the modification of the quantum zero point spin wave energy; i.e. the analogue of the Casimir effect. We show that this interaction is uniformly attractive and falls off as r^{-2 d+1} in d dimensions. For ``stripes'', i.e parallel (d-1)-dimensional hypersurfaces of localized holes, the interaction energy per unit hyperarea is attractive and falls, generically, like r^{-d}. We argue that, in the absence of a long-range Coulomb repulsion between holes, this interaction leads to an instability of any charge-ordered state in the dilute doping limit.Comment: Revtex, 5 pages two-column format, 3 ps figures (epsf). Two references added and some textual change

    Fluctuation-Induced First Order Transition between the Quantum Hall Liquid and Insulator

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    We study the phase transition between the quantum Hall liquid state and the insulating state within the framework of the Chern-Simons-Landau-Ginzburg theory of the quantum Hall effect. For the transition induced by a background periodic potential in the absence of disorder, the model is described by a relativistic scalar field coupled to the Chern-Simons gauge field. For this system, we show that the transition is of the first order, induced by the fluctuations of the gauge field, rather than second order, with statistical angle-dependent scaling exponent.Comment: 5 pages, REVTEX 3.0, two PostScript pictures appended, preprint SU-ITP-94-

    Development of superconducting correlation at low temperatures in the two-dimensional t-J model

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    The equal-time pairing correlation function of the two-dimensional t-J model on a square lattice is studied using a high-temperature expansion method. The sum of the pairing correlation, its spatial dependence, and the correlation length are obtained as functions of temperature down to T0.2tT \simeq 0.2 t. By comparison of single-particle contributions in the correlation functions, we find an effective attractive interaction between quasi-particles in dx2y2d_{x^2-y^2}-wave pairings. It is shown that d-wave correlation grows rapidly at low temperatures for 0.5 < n < 0.9, with n being the electron density. The temperature for this growth is roughly scaled by J/2. This is in sharp contrast to the Hubbard model in a weak or intermediate coupling region, where there is no numerical evidence of superconductivity.Comment: 4 pages, 5 figure

    Phase Diagram of Integer Quantum Hall Effect

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    The phase diagram of integer quantum Hall effect is numerically determined in the tight-binding model, which can account for overall features of recently obtained experimental phase diagram. In particular, the quantum Hall plateaus are terminated by two distinct insulating phases, characterized by the Hall resistance with classic and quantized values, respectively, which is also in good agreement with experiments.Comment: 4 pages, RevTex, 4 PostScript figures; one new figure is added; minor modifications in the tex

    Duality Near Quantum Hall Transitions

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    A recent experiment by Shahar et al, on the phase transitions between quantum Hall states and the insulator, found that the current-voltage characteristics in the two phases are related by symmetry. It was suggested in this work that this is evidence for charge-flux duality near quantum Hall transitions. Here we provide details of this analysis. (Appearances notwithstanding, this is a theoretical paper.)Comment: 26 pages, Revtex 3.

    Edge Dynamics in Quantum Hall Bilayers II: Exact Results with Disorder and Parallel Fields

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    We study edge dynamics in the presence of interlayer tunneling, parallel magnetic field, and various types of disorder for two infinite sequences of quantum Hall states in symmetric bilayers. These sequences begin with the 110 and 331 Halperin states and include their fractional descendants at lower filling factors; the former is easily realized experimentally while the latter is a candidate for the experimentally observed quantum Hall state at a total filling factor of 1/2 in bilayers. We discuss the experimentally interesting observables that involve just one chiral edge of the sample and the correlation functions needed for computing them. We present several methods for obtaining exact results in the presence of interactions and disorder which rely on the chiral character of the system. Of particular interest are our results on the 331 state which suggest that a time-resolved measurement at the edge can be used to discriminate between the 331 and Pfaffian scenarios for the observed quantum Hall state at filling factor 1/2 in realistic double-layer systems.Comment: revtex+epsf; two-up postscript at http://www.sns.ias.edu/~leonid/ntwoup.p
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