Large non-adiabatic hole polarons and matrix element effects in the angle-resolved photoemission spectroscopy of dielectric cuprates

It has been made an extention of the conventional theory based on the assumption of the well isolated Zhang-Rice singlet to be a first electron-removal state in dielectric copper oxide. One assumes the photohole has been localised on either small (pseudo)Jahn-Teller polaron or large non-adiabatic polaron enclosed one or four to five $CuO_4$ centers, respectively, with active one-center valent $(^{1}A_{1g}-{}^{1,3}E_{u})$ manifold. In the framework of the cluster model we have performed a model microscopic calculation of the ${\bf k}$-dependence of the matrix element effects and photon polarization effects for the angle-resolved photoemission in dielectric cuprate like $Sr_{2}CuO_{2}Cl_{2}$. We show that effects like the ''remnant Fermi surface'' detected in ARPES experiment for $Ca_{2}CuO_{2}Cl_{2}$ may be, in fact, a reflection of the matrix element effects, not a reflection of the original band-structure Fermi surface, or the strong antiferromagnetic correlations. The measured dispersion-like features in the low-energy part of the ARPES spectra may be a manifestation of the complex momentum-dependent spectral line-shape of the large PJT polaron response, not the dispersion of the well-isolated Zhang-Rice singlet in antiferromagnetic matrix.Comment: 16 pages, TeX, 9 eps figures adde

Si(111) strained layers on Ge(111): evidence for c(2x4) domains

The tensile strained Si(111) layers grown on top of Ge(111) substrates are studied by combining scanning tunneling microscopy, low energy electron diffraction and first-principles calculations. It is shown that the layers exhibit c(2x4) domains, which are separated by domain walls along directions. A model structure for the c(2x4) domains is proposed, which shows low formation energy and good agreement with the experimental data. The results of our calculations suggest that Ge atoms are likely to replace Si atoms with dangling bonds on the surface (rest-atoms and adatoms), thus significantly lowering the surface energy and inducing the formation of domain walls. The experiments and calculations demonstrate that when surface strain changes from compressive to tensile, the (111) reconstruction converts from dimer-adatom-stacking fault-based to adatom-based structures

Application of wavelet analysis to numerical modeling of deformations in multilevel hierarchical structures

This paper proposes a wavelet based numerical method for the solution of elastoplastic problem. The method i

Phase equilibria and thermodynamic properties of oxide systems on the basis of rare earth, alkaline earth and 3d-transition (Mn, Fe, Co) metals. A short overview of

Review is dedicated studies of phase equilibria in the systems based on rare earth elements and 3d transition metals. It’s highlighted several structural families of these compounds and is shown that many were found interesting properties for practical application, such as high conductivity up to the superconducting state, magnetic properties, catalytic activity of the processes of afterburning of exhaust gases, the high mobility in the oxygen sublattice and more

Mass distributions for nuclear disintegration from fission to evaporation

By a proper choice of the excitation energy per nucleon we analyze the mass distributions of the nuclear fragmentation at various excitation energies. Starting from low energies (between 0.1 and 1 MeV/nucleon) up to higher energies about 12 MeV/n, we classified the mass yield characteristics for heavy nuclei (A>200) on the basis of Statistical Multifragmentation Model. The evaluation of fragment distribution with the excitation energy show that the present results exhibit the same trend as the experimental ones.Comment: 5 pages, 3 figure

Multimedia support discipline «applied metrology» in the preparation of bachelors

The article discusses the formation of competence in the study of special disciplines at bachelor profiling Certification, Metrology and quality control in mechanical engineering. Developed electronic system will allow students of all forms of education to increase the level of preparedness in academic discipline through the organization of their independent work during the preparation for the exam and write a term paper, and perform qualifying work.Рассматривается формирование компетентности при изучении специальной отраслевой дисциплины у бакалавров профилизации «Сертификация, метрология и управление качеством в машиностроении». Разрабатываемый электронный комплекс позволит студентам всех форм обучения повысить уровень подготовленности по учебной дисциплине посредством организации самостоятельной работы при подготовке к сдаче экзамена и написании курсовой работы, а также при выполнении выпускной квалификационной работы

Multimedia support in the study of special subjects of sectoral training

Discusses the formation of industrial-technological competency of vocational training in the field of technical regulation and metrology using modern teaching technologiesРассматривается формирование производственно-технологической компетентности бакалавра профессионального обучения в области технического регулирования и метрологии с использованием современных педагогических технологий и средст