The Ferromagnetism in the Vicinity of Lifshitz Topological Transitions

We show that the critical temperature of a ferromagnetic phase transition in a quasi-two-dimensional hole gas confined in a diluted magnetic semiconductor quantum well strongly depends on the hole chemical potential and hole density. The significant variations of the the Curie temperature occur close to the Lifshitz topological transition points where the hole Fermi surface acquires additional components of topological connectivity due to the filling of excited size-quantization subbands. The model calculations demonstrate that the Curie temperature can be doubled by a small variation of the gate voltage for the CdMnTe/CdMgTe quantum well based device

THE IMAGE OF SOCIALLY ACTIVE INDIVIDUAL IN THE REPRESENTATIONS OF STUDENT YOUTH

The study of students’ representations of a socially active individual is one of the major tasks of psychology of education. The purpose of the study is to carry out analysis of characteristics of an image of a socially active individual in the representations of student youth and to correlate them with self-assessment of social activity and assessment of real social activity. Students aged 17-23 years (n=251) took part in the study ?=20.11, SD=1.2 (41% men). We used the polling method with the scales developed by the authors of the present study in order to identify self-assessment of social activity, to evaluate real activity; and the associative experiment method. In the study we analysed qualitative and quantitative characteristics of the image of a socially-active individual in the representations of university students. We have established major meaningful characteristics of representations (personal qualities, self-improvement and personal transformation, states, representation in the group, process and activity-related characteristics). Conclusion has been made about the connection between the intensity of students’ social activity and cognitive complexity of the image of a socially active individual and the content of subjective (initiative, confidence) and psychodynamic (vigour) categories in it

Coherent spin dynamics of electrons and holes in CsPbBr3_3 perovskite crystals

The lead halide perovskites demonstrate huge potential for optoelectronic applications, high energy radiation detectors, light emitting devices and solar energy harvesting. Those materials exhibit strong spin-orbit coupling enabling efficient optical orientation of carrier spins in perovskite-based devices with performance controlled by a magnetic field. Perovskites are promising for spintronics due to substantial bulk and structure inversion asymmetry, however, their spin properties are not studied in detail. Here we show that elaborated time-resolved spectroscopy involving strong magnetic fields can be successfully used for perovskites. We perform a comprehensive study of high-quality CsPbBr$_3$ crystals by measuring the exciton and charge carrier $g$-factors, spin relaxation times and hyperfine interaction of carrier and nuclear spins by means of coherent spin dynamics. Owing to their "inverted" band structure, perovskites represent appealing model systems for semiconductor spintronics exploiting the valence band hole spins, while in conventional semiconductors the conduction band electrons are considered for spin functionality.Comment: 8 pages, 3 figures + supplementary informatio

Influence of plasma volume discharge in atmospheric-pressure air on the admittance of MIS structures based on MBE p-HgCdTe

This article investigates the effect of a nanosecond plasma volume discharge, which is formed in an inhomogeneous electrical field at atmospheric pressure, on the electrical properties of MIS structures based on HgCdTe (MCT) epitaxial films. The MIS structure based on films exposed to the discharge significantly changed its main parameters. The most notable feature of the structure exposed to discharge is the significant increase in the positive fixed charge in the insulator. A possible reason for changes in the characteristics of MIS structure after exposure to discharge is the significant change in the impurity-defect system of the semiconductor near the interface. This is accompanied with a formation of an insulator film of nanometer thickness on the surface, which gives rise to positive fixed charge

Estimation of the impact of large regional investment projects on the regional development on the example of Universiade-2013

© 2015, Mediterranean Center of Social and Educational Research. All rights reserved. The work reveals and classifies the main socio-economic consequences of large international competitions. The impact of a large international sporting event on the socio-economic development of the host region is characterized with the institutional approach on the example of Universiade 2013 in Kazan. The impact of the Universiade on the socio-economic development in Tatarstan is estimated by economic sectors. In particular, the construction industry, hospitality industry, tourism, education in the Republic of Tatarstan are considered

On bi-integrable natural Hamiltonian systems on the Riemannian manifolds

We introduce the concept of natural Poisson bivectors, which generalizes the Benenti approach to construction of natural integrable systems on the Riemannian manifolds and allows us to consider almost the whole known zoo of integrable systems in framework of bi-hamiltonian geometry.Comment: 24 pages, LaTeX with AMSfonts (some new references were added