Exact diagonalization solver for the extended dynamical mean-field theory

We present an efficient exact diagonalization scheme for the extended dynamical mean-field theory and apply it to the extended Hubbard model on the square lattice with nonlocal charge-charge interactions. Our solver reproduces the phase diagram of this approximation with good accuracy. Details on the numerical treatment of the large Hilbert space of the auxiliary Holstein-Anderson impurity problem are provided. Benchmarks with a numerically exact strong-coupling continuous-time quantum-Monte Carlo solver show better convergence behavior of the exact diagonalization in the deep insulator. Special attention is given to possible effects due to the discretization of the bosonic bath. We discuss the quality of real axis spectra and address the question of screening in the Mott insulator within extended dynamical mean-field theory.Comment: 12 pages, 8 figure

Some Aspects of the Evolution of Political Elites in the Countries of Eurasia

The second decade of the XXI century in the Eurasian space was marked by new socio-economic and political developments. Significant changes have taken place in the political landscape of Eurasia. They were largely due to the fact that the political processes in which the Eurasian states that appeared on the map of Eurasia after the collapse of the USSR began to change their character. New political actors have entered the arena of political activity, gradually replacing people from the former party nomenclature. The political elite was now formed not from graduates of the Soviet higher school, but mainly from those who received education in higher educational institutions of Great Britain, Germany, China, the USA, Turkey, France, Japan, etc. The consequence was the reorientation of such politicians, political scientists, administrative workers from the traditional values of Euro-Asian peoples to liberal pseudo-traditions characteristic of for the realities of transatlantic states (“hedonism for the body and narcissism for the soul”).Researchers note the generational change of political figures taking place in Central Asia today, the change in the composition of political elites, their positions in relation to neighboring countries and states that they consider as investors and allies. In the conditions of the SVO in Ukraine and the ongoing sanctions pressure on Russia, Russophobic sentiments have significantly increased both among the ruling circles and among ordinary residents of the Eurasian states. The media are especially trying to emphasize and develop this. The article provides examples of recent events in a number of EAEU countries and neighboring Eurasian states. Attention is drawn to the need for a wider dissemination of historical information about political and other events of modern and modern times in the Great Steppe. The effectiveness of the application of the principles and methods of economic, political, and cultural interaction of various state entities accumulated over the centuries in the heart of Eurasia is emphasized. Attention is drawn to the effectiveness of using education as a means of soft power to ensure the sustainable development of the states of the region. The prospects for the change of political generations, the need for “rejuvenation” of political elites are briefly described.Aim. To highlight significant aspects and perspectives of the evolution of political elites in Central Asian countries.Tasks. To introduce into scientific circulation the results of a comparative analysis of the formation and activity of political elites of new state formations in Eurasia at the present stage.Methods. Comparative-analytical method, systematic approach, transdisciplinary approach.Results. The changes in the political landscape of Eurasia and their impact on the activities of the political elites of the Central Asian countries are characterized. New elements of the state of the regional integration process are highlighted. The results of the use of education as a means of soft power in the change of political generations in the states of the region are shown.Conclusions. In modern conditions, a significant factor in the formation of a new political landscape on the Eurasian continent is the emergence of new centers of power and the change of political generations of the ruling ones. It is necessary to expand the use of historical experience in the implementation of vocational education to include young people in the management system in the Eurasian states

Renormalized spectral function for Co adatom on the Pt(111) surface

The strong Coulomb correlations effects in the electronic structure of magnetic Co adatom on the Pt(111) surface have been investigated. Using a realistic five d-orbital impurity Anderson model at low temperatures with parameters determined from first-principles calculations we found a striking change of the electronic structure in comparison with the LDA results. The spectral function calculated with full rotationally invariant Coulomb interaction is in good agreement with the quasiparticle region of the STM conductance spectrum. Using the calculated spin-spin correlation functions we have analyzed the formation of the magnetic moments of the Co impurity orbitals.Comment: 4 pages, 4 figure

UV Curable Self-Healing Structural Epoxy Composite Materials Interfacial Polycondensation Microencapsulation of Healing Agent and Photo-Initiator

The ability of polymeric coatings to self-heal itself from mechanical damage is explored in this paper. Polymeric coatings with self-healing property is one of the important aspects in modern science. It can be used in industries such as oil industry (protection against corrosion), mechanical engineering, aircraft, etc. The polyurethane (PU) microparticles were synthesized on the basis of polypropyleneglycol (PPG) and toluene diisocyanate (TDI) with a method of interfacial polycondensation at the interface water-benzene. Further to study the surface morphology of the microcapsules with healing agent (trimethylolpropanetriacrylate– TMPTA) obtained PU was applied the method of scanning electron and atomic force microscopy. The PU microparticles hollow inside have regular spherical shape with a diameter of 5-10 µm with a dense and smooth polymerics shell. The resulting polyimide–polyurethane (PI–PU) composites have high potential to regenerate damaged surfaces not only on the surface and also in the volume of composite within several minutes

Local Plaquette Physics as Key Ingredient of High-Temperature Superconductivity in Cuprates

A major pathway towards understanding complex systems is given by exactly solvable reference systems that contain the essential physics of the system. For the $t-t'-U$ Hubbard model, the four-site plaquette is known to have a quantum critical point in the $U-\mu$ space where states with electron occupations $N=2, 3, 4$ per plaquette are degenerate [Phys. Rev. B {\bf 94}, 125133 (2016)]. We show that such a critical point in the lattice causes an instability in the particle-particle singlet d-wave channel and manifests some of the essential elements of the cuprate superconductivity. For this purpose we design an efficient superperturbation theory -- based on the dual fermion approach -- with the critical plaquette as the reference system. Thus, the perturbation theory already contains the relevant d-wave fluctuations from the beginning via the two-particle correlations of the plaquette. We find that d-wave superconductivity remains a leading instability channel under reasonably broad range of parameters. The next-nearest-neighbour hopping $t'$ is shown to play a crucial role in a formation of strongly bound electronic bipolarons whose coherence at lower temperature results in superconductivity. The physics of the pseudogap within the developed picture is also discussed.Comment: 25 pages, 28 figure

Generation of Magnetic Field by Combined Action of Turbulence and Shear

The feasibility of a mean-field dynamo in nonhelical turbulence with superimposed linear shear is studied numerically in elongated shearing boxes. Exponential growth of magnetic field at scales much larger than the outer scale of the turbulence is found. The charateristic scale of the field is l_B ~ S^{-1/2} and growth rate is gamma ~ S, where S is the shearing rate. This newly discovered shear dynamo effect potentially represents a very generic mechanism for generating large-scale magnetic fields in a broad class of astrophysical systems with spatially coherent mean flows.Comment: 4 pages, 5 figures; replaced with revised version that matches the published PR

Promising Domestic Vegetable Oil and Its Qualitative Characteristics

This article describes the relevance and importance of the production of promising oilseeds, including safflower oil, which is one of the main directions for the development of the agro-industrial industry in Kazakhstan. The purpose of the work is to demonstrate the usefulness of safflower oil with the results of scientific research and increase its popularity among manufacturers and consumers. The results of the study revealed the benefits of safflower oil for human health, and also described the benefits of growing safflower for the country's economy. Qualitative indicators of safflower oil are based on modern physico-chemical and analytical research methods. According to the results of the study, it was found that safflower oil contains α-tocopherols and phylloquinones, omega-6 unsaturated fatty acids in the amount of 74.82% and many minerals. It is reported about the therapeutic and preventive effects on the human body of fatty acids and vitamins contained in safflower oil. The data and research results presented in the article can become the basis for future scientific work and help in the prevention and treatment of various diseases. Currently, due to the growth of safflower cultivation areas in Kazakhstan, the prospects for the efficiency of consumption and exportation of safflower are shown not as a raw material, but as a product with full medicinal properties

Valence fluctuations and empty-state resonance for Fe adatom on a surface

We report on the formation of the high-energy empty-state resonance in the electronic spectrum of the iron adatom on the Pt(111) surface. By using the combination of the first-principles methods and the finite-temperature exact diagonalization approach, we show that the resonance is the result of the valence fluctuations between atomic configurations of the impurity. Our theoretical finding is fully confirmed by the results of the scanning tunneling microscopy measurements [M. F. Crommie, Phys. Rev. B 48, 2851 (1993)PRBMDO1098-012110.1103/PhysRevB.48.2851]. In contrast to the previous theoretical results obtained by using local spin density approximation, the paramagnetic state of the impurity in the experiment is naturally reproduced within our approach. This opens a way for interpretation of STM data collected earlier for metallic surface nanosystems with iron impurities. ©2015 American Physical Society

WAYS OF SOLVING THE PROBLEMS OF THE TECHNOLOGY OF PRIMARY CLEANING OF SAFLOROUS OIL

Recently, the demand for safflower products has been growing year by year, due to the increase in acreage and the popularity of safflower oil among consumers. On the basis of research works, a technological line for the production of safflower oil is considered. As a result, due to the insufficiently in-depth study and widespread use of safflower oil production technology, many problems remain unresolved. For example, for initial purification, post-press safflower oil technology was studied to update and define it, and a sample of post-press crude safflower oil was transferred to a special laboratory. To solve the problems that have arisen, an effective method for purifying crude safflower oil after pressing has been proposed, and a filter-precipitating centrifuge has been improved

Orbital-selective conductance of Co adatom on the Pt(111) surface

We propose an orbital-selective model for the transport and magnetic properties of the individual Co impurity deposited on the Pt(111). Using the combination of the Anderson-type Hamiltonian and the Kubo's linear response theory we show that the magnetization and dI/dV spectrum of Co adatom are originated from the 3d states of the different symmetry. A textbook expression for the spin-dependent differential conductance provides a natural connection between magnetic and transport properties of Co/Pt(111). We found that it is possible to detect and to manipulate the different 3d states of the Co adatom by tuning the spin polarization of the tip and tip-impurity distance in STM experiments