Disorder and Interaction in 2D: Exact diagonalization study of the Anderson-Hubbard-Mott model

We investigate, by numerically calculating the charge stiffness, the effects of random diagonal disorder and electron-electron interaction on the nature of the ground state in the 2D Hubbard model through the finite size exact diagonalization technique. By comparing with the corresponding 1D Hubbard model results and by using heuristic arguments we conclude that it is \QTR{it}{unlikely} that there is a 2D metal-insulator quantum phase transition although the effect of interaction in some range of parameters is to substantially enhance the non-interacting charge stiffness.Comment: 13 pages, 2 figures Revised version. Accepted for publication in Phys. Rev. Let

Robust Multi-Partite Multi-Level Quantum Protocols

We present a tripartite three-level state that allows a secret sharing protocol among the three parties, or a quantum key distribution protocol between any two parties. The state used in this scheme contains entanglement even after one system is traced out. We show how to utilize this residual entanglement for quantum key distribution purposes, and propose a realization of the scheme using entanglement of orbital angular momentum states of photons.Comment: 9 pages, 2 figure

Investigation of the Role of Plasticizers in Film-forming Coats for Protecting Cooled Meat

As a result of theoretical studies on problems of protection and prolongation of storage terms of meat, it was revealed, that one of promising directions is to use protecting coats, based on natural biopolymers.The topicality of this study is in studying film-forming coats, based on natural polysaccharides, because they have high mechanical indices, absence of a smell, taste and are subjected to biological destruction. For regulating mechanical properties, the composition of film-creating coats is added with plasticizers of different origins.The aim of this work is in describing characteristics of food films, based on carrageenan, sodium alginate and plasticizers of different origins.There were mechanical, rheological properties of protecting coats. The comparative characteristic of these properties, depending on an added plasticizer, was realized. The type and mechanisms of interaction of components of the film-forming coat and plasticizers were completely described. The viscosity of the film-forming coat with a plasticizer has less values comparing with other solutions. Adding plasticizers resulted in increasing the film elasticity, but at the same time some increase of the firmness was observed.Film-forming coats with adding a plasticizer had a higher limit of fluidity, so they were firmer than complex film-forming coats without a plasticizer. From the other side, deformation values of film-forming coats without adding a plasticizer were higher than ones of complex film-forming coats with adding a plasticizer, because they were firmer.The study of physical properties of developed film-forming coats, based on hydrocolloids, demonstrated that coats with a plasticizer have more gas permeability.According to the results, obtained at experiments it was established, that the film-forming coat, based on sodium alginate, carrageenan and glycerin, has best mechanical, physical and rheological indices

Features of construction of the training process skiers aged 17-18 years to compete in different styles of skiing

The work is devoted to the improvement of precompetitive preparation of skiers, taking into account the need to participate in competitions of different styles of skiing. The experiment included 20 athletes aged 17-18 years. Isolated model characteristics of athletes who successfully perform classic and skating style of movement. The range of indicators of physical fitness of athletes, which is the norm for this level of qualification. The technique of constructing precompetitive preparation of athletes on the basis of a combination of style of movement. It was established experimentally that the combination of training sessions during the day improves athletic performance in racing classic and skating style. In this case, primary and secondary occupation to carry out a different style of skiing with a change of their rotation on the next day

Correlated charge polarization in a chain of coupled quantum dots

Coherent charge transfer in a linear array of tunnel-coupled quantum dots, electrostatically coupled to external gates, is investigated using the Bethe ansatz for a symmetrically biased Hubbard chain. Charge polarization in this correlated system is shown to proceed via two distinct processes: formation of bound states in the metallic phase, and charge transfer processes corresponding to a superposition of antibound states at opposite ends of the chain in the Mott-insulating phase. The polarizability in the insulating phase of the chain exhibits a universal scaling behavior, while the polarization charge in the metallic phase of the model is shown to be quantized in units of $e/2$.Comment: 9 pages, 3 figures, 1 tabl

Local vibrations in real crystals with combined defects

The conditions of formation and the main characteristics of local vibrations due to the presence of light impurities Al, Mg, and Mn in the bulk and on the close-packed [111] surface of the fcc crystal lattice of silver are investigated. The influence of surface roughness is analyzed. Analytical approximations are obtained which describe the frequency and intensity of the local vibrations at the impurity atom and its nearest neighborhood to high accuracy. The proposed analytical approximations provide a practical way of determining the parameters of the defect structure and the interatomic interactions from the experimentally determined characteristics of the local vibrations

Magnetization in short-period mesoscopic electron systems

We calculate the magnetization of the two-dimensional electron gas in a short-period lateral superlattice, with the Coulomb interaction included in Hartree and Hartree-Fock approximations. We compare the results for a finite, mesoscopic system modulated by a periodic potential, with the results for the infinite periodic system. In addition to the expected strong exchange effects, the size of the system, the type and the strength of the lateral modulation leave their fingerprints on the magnetization.Comment: RevTeX4, 10 pages with 14 included postscript figures To be published in PRB. Replaced to repair figure

Electronic structure and magnetic properties of fete, bifeo3, srfe12o19 and srcotife10o19 compounds

The electronic energy structures and magnetic properties of iron-based compounds with group VI elements (FeTe, BiFeO3, SrFe12O19 and SrCoTiFe10O19) are studied using the density functional theory (DFT) methods. Manifestations of different types of chemical bonds in magnetism of these compounds are studied theoretically. Calculations of electronic structures of these systems are performed, by using the generalized gradient approximation (GGA) for the description of the exchange and correlation effects within DFT. For SrFe12O19 and SrCoTiFe10O19 hexaferrites, the GGA + U method is also employed to deal with strongly correlated 3d-electrons. The calculations have revealed distinctive features of the electronic structure of the investigated iron-based compounds with strongly correlated 3d-electrons, which can be responsible for their peculiar structural and magnetic properties

Application of Article 5 of the ECHR to the detention of a person who has committed a criminal offense

Purpose of the article. The purpose of this article is to examine the theoretical and practical aspects of the arrest and transfer by one state to another (upon request) of a person suspected or accused of committing a crime or a convicted offender. Methodology. The authors use such research methods as systems analysis, comparative law, documentary, bibliographic, dialectical, dogmatic, logical-legal, system-structural and modeling methods. Conclusions. After conducting this study, the authors suggested their own ways to solve problematic aspects of the legal regulation of extradition in Ukraine. Originality or value. This study analyzes the Ukrainian legislation and decisions of the European Court of Human Rights. The study of detention outside the territory of Ukraine from the point of view of the national legislation of Ukraine and the European Court of Human Rights is complementary. This article defines the legal grounds and procedure for extradition of persons who have committed a crime outside the territory of Ukraine. The peculiarities of the national legislation in case of detention of a person who has committed a criminal offense outside the territory of Ukraine are analyzed, problematic issues in this area are identified and own solutions are proposed. The aspect of realization of the rights and freedoms of the detainee, including the right to protection, is investigated separately