Microscopic origin of Magnetic Ferroelectrics in Nonlinear Multiferroics

A simple but general microscopic mechanism to understand the interplay between the electric and magnetic degrees of freedom is developed. Within this mechanism, the magnetic structure generates an electric current which induce an counterbalance electric current from the spin orbital coupling. When the magnetic structure is described by a single order parameter, the electric polarization is determined by the single spin orbital coupling parameter, and the material is predicted to be a half insulator. This mechanism provides a simple estimation of the value of ferroelectricity and sets a physical limitation as well.Comment: 4 pages, 1 figur

Finite-sample and asymptotic sign-based tests for parameters of non-linear quantile regression with Markov noise

One of the most noticeable features of sign-based statistical procedures is an opportunity to build an exact test for simple hypothesis testing of parameters in a regression model. In this article, we expanded a sing-based approach to the nonlinear case with dependent noise. The examined model is a multi-quantile regression, which makes it possible to test hypothesis not only of regression parameters, but of noise parameters as well

Non-circular semiconductor nanorings of type I and II: Emission kinetics in the exciton Aharonov-Bohm effect

Transition energies and oscillator strengths of excitons in dependence on magnetic field are investigated in type I and II semiconductor nanorings. A slight deviation from circular (concentric) shape of the type II nanoring gives a better observability of the Aharonov-Bohm oscillations since the ground state is always optically active. Kinetic equations for the exciton occupation are solved with acoustic phonon scattering as the major relaxation process, and absorption and luminescence spectra are calculated showing deviations from equilibrium. The presence of a non-radiative exciton decay leads to a quenching of the integrated photoluminescence with magnetic field.Comment: The first version submitted to Phys. Rev. B on April 16, 2007. Revised (this) version on July 31, 200

Epitaxial checkerboard arrangement of nanorods in ZnMnGaO4 films studied by x-ray diffraction

The intriguing nano-structural properties of a ZnMnGaO4 film epitaxially grown on MgO (001) substrate have been investigated using synchrotron radiation-based x-ray diffraction. The ZnMnGaO4 film consisted of a self-assembled checkerboard (CB) structure with perfectly aligned and regularly spaced vertical nanorods. The lattice parameters of the orthorhombic and rotated tetragonal phases of the CB structure were analyzed using H-K, H-L, and K-L cross sections of the reciprocal space maps measured around various symmetric and asymmetric reflections of the spinel structure. We demonstrate that the symmetry of atomic displacements at the phases boundaries provides the means for coherent coexistence of two domains types within the volume of the film

СТАН ТА ТЕНДЕНЦІЇ МІЖБЮДЖЕТНОГО РЕГУЛЮВАННЯ В УКРАЇНІ В УМОВАХ ФІСКАЛЬНОЇ ДЕЦЕНТРАЛІЗАЦІЇ

A balanced socio-economic development of any country is closely related to the efficiency of the system of intergovernmental relations, which should be aimed at optimizing the process of fiscal decentralization and clear definition of the powers of local government. Interbudgetary regulation in Ukraine reflects processes of the national and political importance and is of great importance in the composition of intergovernmental fiscal relations, which priority is growing in terms of decentralization reforms. Purpose. The main objectives of this study are: to summarize a complex task that is resolved in the process of budgetary control; to analyze the dynamics of revenues of the consolidated budget of Ukraine in 2007-2016 and the proportion of own local revenues in GDP; to distinguish formation features of Ukrainian local budgets by region; to analyze volumes of local budgets per capita in terms of area; to highlight the leverage rate of local budgets; to analyze the share of interbudget transfers in total local budgets. Results. The study is a synthesis of the complex challenges that must be resolved in the process of budgetary control, such as: balancing the budget; foster the interest of local governments in the maximum revenue mobilization; reallocation of existing budgetary resources, taking into account local features. The dynamics of the revenues of the consolidated budget of Ukraine in 2007-2016 was analyzed and concluded that the proportion of own local revenues in GDP tended to decrease with a simultaneous increase in the share of the interbudget transfers from the state budget. Abovementioned resulted in the ensuring of a stable share of local budgets in the GDP structure (at 14-15%). As a result of the intergovernmental fiscal decentralization reform by the results of 2016 the share of own revenues of local budgets Ukraine in GDP rose to 7.2%, or 1.1% compared to 2015 with a simultaneous decrease in the interbudget transfers share from the state budget to 8.2% (0.6% compared to 2015). Analyzed the share interbudget transfers in total local budgets, which for a long period tended to increase (from 47.2% in 2007 to 53.4% in 2016), which is contrary to the basic principles of fiscal decentralization. Conclusion. Grounded features of Ukrainian local budget revenues by region and proved that the unevenness of income between regions of Ukraine are often equivalent to the level of industrial production. Analyzed volumes of local budgets per capita in terms of area. Presented the list of influence instruments on local budgets indexes of incomes, including the increase in the minimum wage, inflation, continuing reform of the budget system in the direction of fiscal decentralization and transfer volumes.Представлен комплекс задач, который должен решаться в процессе межбюджетного регулирования, проанализирована динамика доходной части сводного бюджета Украины в 2007-2016 гг. и удельный вес собственных доходов местных бюджетов в структуре ВВП, выделены особенности формирования доходов местных бюджетов Украины по регионам. Проанализированы объемы доходов местных бюджетов на душу населения в разрезе территорий, освещены рычаги влияния на показатель доходов местных бюджетов, проведен анализ удельного веса межбюджетных трансфертов в общей структуре местных бюджетов.Узагальнено комплекс завдань, що має вирішуватись у процесі міжбюджетного регулювання, проаналізовано динаміку дохідної частини зведеного бюджету України у 2007–2016 рр. та питому вагу власних доходів місцевих бюджетів в структурі ВВП, виокремлено особливості формування доходів місцевих бюджетів України за регіонами. Проаналізовано обсяги доходів місцевих бюджетів на душу населення у розрізі територій, висвітлено важелі впливу на показник доходів місцевих бюджетів, здійснено аналіз питомої ваги міжбюджетних трансфертів у загальній структурі місцевих бюджетів

Electron cyclotron mass in undoped CdTe/CdMnTe quantum wells

Optically detected cyclotron resonance of two-dimensional electrons has been studied in nominally undoped CdTe/(Cd,Mn)Te quantum wells. The enhancement of carrier quantum confinement results in an increase of the electron cyclotron mass from 0.099$m_0$ to 0.112$m_0$ with well width decreasing from 30 down to 3.6 nm. Model calculations of the electron effective mass have been performed for this material system and good agreement with experimental data is achieved for an electron-phonon coupling constant $\alpha$=0.32

Bifurcations observed in the spectra of coupled electron-phonon modes in multiferroic PrFe3(BO3)4PrFe_3(BO_3)_4 subjected to a magnetic field

We report on bifurcations effect mediated by the electron-phonon coupling in a concentrated rare-earth-containing antiferromagnet, observed in the spectra of coupled $4f$-electron-phonon modes under the influence of an external magnetic field. The effect was observed in the low-temperature far-infrared (terahertz) reflection spectra of a multiferroic easy-axis antiferromagnet $PrFe_3(BO_3)_4$ in magnetic fields $\textbf{B}_{ext}||c$. Both paramagnetic and magnetically ordered phases (including a spin-flop one) were studied in magnetic fields up to 30 T. We show that the field behavior of the coupled modes can be successfully explained and modeled on the base of the equation derived in the frame of the theory of coupled electron-phonon modes, with the same field-independent electron-phonon interaction constant $|W| = 14.8 cm^{-1}$.Comment: 5 pages, 4 figure