Theoretical investigation of TbNi_{5-x}Cu_x optical properties

In this paper we present theoretical investigation of optical conductivity for intermetallic TbNi_{5-x}Cu_x series. In the frame of LSDA+U calculations electronic structure for x=0,1,2 and on top of that optical conductivities were calculated. Disorder effects of Ni for Cu substitution on a level of LSDA+U densities of states (DOS) were taken into account via averaging over all possible Cu ion positions for given doping level x. Gradual suppression and loosing of structure of optical conductivity at 2 eV together with simultaneous intensity growth at 4 eV correspond to increase of Cu and decrease of Ni content. As reported before [Knyazev et al., Optics and Spectroscopy 104, 360 (2008)] plasma frequency has non monotonic doping behaviour with maximum at x=1. This behaviour is explained as competition between lowering of total density of states on the Fermi level N(E_F) and growing of number of carriers. Our theoretical results agree well with variety of recent experiments.Comment: 4 pages, 3 figure

Algebraic approach to the spectral problem for the Schroedinger equation with power potentials

The method reducing the solution of the Schroedinger equation for several types of power potentials to the solution of the eigenvalue problem for the infinite system of algebraic equations is developed. The finite truncation of this system provides high accuracy results for low-lying levels. The proposed approach is appropriate both for analytic calculations and for numerical computations. This method allows also to determine the spectrum of the Schroedinger-like relativistic equations. The heavy quarkonium (charmonium and bottomonium) mass spectra for the Cornell potential and the sum of the Coulomb and oscillator potentials are calculated. The results are in good agreement with experimental data.Comment: 17 pages, including 6 PostScript figures (epsf style

Nucleon-nucleon wave function with short-range nodes and high-energy deuteron photodisintegration

We review a concept of the Moscow potential (MP) of the $NN$ interaction. On the basis of this concept we derive by quantum inversion optical partial potentials from the modern partial-wave analysis (PWA) data and deuteron properties. Point-form (PF) relativistic quantum mechanics (RQM) is applied to the two-body deuteron photodisintegration. Calculations of the cross-section angular distributions cover photon energies between 1.1 and 2.5 GeV. Good agreement between our theory and recent experimental data confirms the concept of deep attractive Moscow potential with forbidden $S$- and $P$-states.Comment: 31 pages, 9 figures. typos, extended formalism, review of the Moscow potential model adde

Os problemas do desenvolvimento do campo legal na Rússia dos primeiros tempos recentes (finais de XV - o comienzo del siglo XVII)

The article deals with the problems associated with the peculiarities of a single legal field development in the Russian state during the epoch of the early modern era (traditionally associated in Russian historiography with the times of a single centralized state formation and development and the emergence of autocracy as a kind of early absolutism). Using a number of provisions of modern concepts for the development of early modern states in Europe, the authors of the article put forward the thesis of a single legal field development in the Russian state during the period under consideration based on the analysis of Russian law monuments at the end of the XVth century (The Code of Law of Ivan III in 1497) and the 16th century (first of all, the code of law by Ivan IV, as well as a number of other legislative and legal acts) and judicial practice. In their opinion, this incompleteness was related with the following circumstances. First of all, the development of political and legal institutions in the early modern Russian state was of an evolutionary nature and, therefore, denied radical changes. Secondly, the poverty of the state caused the relative weakness and a slow development of "sinews of power" and, therefore, prevented the establishment of a more stringent administrative and legal control by the supreme power over the actions of local authorities. Finally, the weakness of the mentioned "sinews of power" conditioned the need of cooperation mode establishment between the supreme authority and local elites, while retaining the access to the exercise of power functions on the ground - also through the preservation of the old legal customs and traditions. Naturally, all this contributed to the preservation and the reproduction of the legal "antiquity" and, consequently, the incompleteness of legal centralization process and the formation of a single legal field throughout the country. The legal field, in the opinion of the authors of the article, had at least 2-level character all this time, the fragmented nature and the dispersion at the low-rank level.El artículo trata los problemas asociados con las peculiaridades de un desarrollo de campo legal único en el estado ruso durante la época moderna temprana (tradicionalmente asociado en la historiografía rusa con los tiempos de una formación y desarrollo estatal centralizado único y el surgimiento de la autocracia como una especie de absolutismo temprano). Usando una serie de disposiciones de conceptos modernos para el desarrollo de los estados modernos tempranos en Europa, los autores del artículo presentaron la tesis de un desarrollo de campo legal único en el estado ruso durante el período bajo consideración basado en el análisis de monumentos de derecho rusos a fines del siglo XV (El Código de Derecho de Iván III en 1497) y el siglo XVI (ante todo, el código de leyes de Iván IV, así como una serie de otros actos legislativos y jurídicos) y la práctica judicial . En su opinión, este estado incompleto estaba relacionado con las siguientes circunstancias. En primer lugar, el desarrollo de las instituciones políticas y legales en el estado ruso moderno temprano fue de naturaleza evolutiva y, por lo tanto, negó los cambios radicales. En segundo lugar, la pobreza del estado causó la debilidad relativa y un lento desarrollo de "tendones de poder" y, por lo tanto, impidió el establecimiento de un control administrativo y legal más estricto por parte del poder supremo sobre las acciones de las autoridades locales. Finalmente, la debilidad de los mencionados "nervios de poder" condicionó la necesidad del establecimiento del modo de cooperación entre la autoridad suprema y las elites locales, mientras se mantiene el acceso al ejercicio de las funciones de poder sobre el terreno, también a través de la preservación de las viejas costumbres legales y tradiciones Naturalmente, todo esto contribuyó a la preservación y reproducción de la "antigüedad" legal y, en consecuencia, a la incompletitud del proceso de centralización legal y la formación de un solo campo legal en todo el país. El campo legal, en opinión de los autores del artículo, tenía al menos un carácter de dos niveles todo este tiempo, la naturaleza fragmentada y la dispersión en el nivel de bajo rango. O artigo trata os problemas associados com as peculiaridades de um curso de campo legal no estado ruso durante a época moderna temático (tradicionalmente associado à historiografia rusa com os tempos de uma formação e desenvolvimento estatal centralizado único e o surgimento da autocracia como una especie de absolutismo temprano). Using una serie de disposiciones de conceptos modernes para o desenvolvimento dos estados modernos templos na Europa, os autores do artigo apresentando a tese de um curso de campo legal no estado do ruso durante o período considerado de base na análise de pontos de vista ruses a fins del siglo XV (O código de direito de Iván III em 1497) e o século XVI (ante, o código de leyes de Iván IV, como uma série de atos legislativos e jurídicos) e a prática judicial. Em sua opinião, este estado incompleto está relacionado com as circunstâncias circunstanciadas. Em primeiro lugar, o desenvolvimento das instituições políticas e jurídicas no estado atual temprano naturalidade evolutiva e, por isso, os dois cambios radicais. Em segundo lugar, a pobreza do estado causou a debilidade relativa e um lento desenvolvimento de "tendões de poder" e, por que tanto, impiedoso o estabelecimento de um controle administrativo e jurídico mais estrito por parte do poder supremo sobre as ações das autoridades locales. Finalmente, a debilidad das perdas "nervos de poder" é a necessidade do estabelecimento do modo de cooperação entre a supremacia e as elites locais, mientras se mantém o acceso ao exercicio das funções de poder sobre o terreno, tambem a través de la preservación de las viejas costumbres legales y tradiciones Naturalmente, todo esto contribuído a la preservación y reproducción de la "antigüedad" legal y, en consecuencia, a incompletitud del proceso de centralización legal y la formación de un solo campo legal en todo el país . O campo legal, na opinião dos autores do artigo, com o menos um carácter dos niveles todo este tempo, a natureza fragmentada e a dispersão no nivel de bajo rango

Quark-antiquark potential with retardation and radiative contributions and the heavy quarkonium mass spectra

The charmonium and bottomonium mass spectra are calculated with the systematic account of all relativistic corrections of order v^2/c^2 and the one-loop radiative corrections. Special attention is paid to the contribution of the retardation effects to the spin-independent part of the quark-antiquark potential, and a general approach to accounting for retardation effects in the long-range (confining) part of the potential is presented. A good fit to available experimental data on the mass spectra is obtained.Comment: 20 pages, revtex, 2 Postscript figure

Magnetic vortex as a ground state for micron-scale antiferromagnetic samples

Here we consider micron-sized samples with any axisymmetric body shape and made with a canted antiferromagnet, like hematite or iron borate. We find that its ground state can be a magnetic vortex with a topologically non-trivial distribution of the sublattice magnetization $\vec{l}$ and planar coreless vortex-like structure for the net magnetization $\vec{M}$. For antiferromagnetic samples in the vortex state, in addition to low-frequency modes, we find high-frequency modes with frequencies over the range of hundreds of gigahertz, including a mode localized in a region of radius $\sim$ 30--40 nm near the vortex core.Comment: 20 pages, 1 figur