Goldstone mode of Skyrmion Crystal

We discuss the Goldstone mode of skyrmion crystal in a model of two-dimenssional ferromagnet with Dzyaloshinskii-Moriya interaction in magnetic field. We use stereographic projection approach to construct skyrmion crystal and consider skyrmion's displacement field. The small overlap of the individual skyrmion images restricts the potential energy to the interaction of nearest neighboring displacements. The closed form of the Goldstone mode dispersion is found and its dependence on the magnetic field is studied. We use semiclassical quantization to define the Green's function and show that the propagation of displacements through the crystal changes its tensorial form from isotropic to anisotropic one at large distances.Comment: 6 pages, 4 figure

Magnon topological transition in skyrmion crystal

We study the magnon spectrum in skyrmion crystal formed in thin ferromagnetic films with Dzyalosinskii-Moria interaction in presence of magnetic field. Focusing on two low-lying observable magnon modes and employing stereographic projection method, we develop a theory demonstrating a topological transition in the spectrum. Upon the increase of magnetic field, the gap between two magnon bands closes, with the ensuing change in the topological character of both bands. This phenomenon of gap closing, if confirmed in magnetic resonance experiments, may deserve further investigation by thermal Hall conductivity experiments.Comment: 6 pages, 4 figure

People with mental disability as human rights carriers: the example of implementing the right to education in Russia

This study was aimed at investigating the realization of the right to education as a human right for people with mental disabilities in the context of Russi

RKKY interaction in the nearly-nested Fermi liquid

We present the results of analytical evaluation of the indirect RKKY interaction in a layered metal with nearly nested (almost squared) Fermi surface. The final expressions are obtained in closed form as a combination of Bessel functions. We discuss the notion of the ``2k_F'' oscillations and show that they occur as the far asymptote of our expressions. We show the existence of the intermediate asymptote of the interaction which is of the sign-reversal antiferromagnetic type and is the only term surviving in the limit of exact nesting. A good accordance of our analytical formulas with numerical findings is demonstrated until the interatomic distances. The obtained expressions for the Green's functions extend the previous analytical results into the region of intermediate distances as well.Comment: 9 pages, REVTEX, 3 .eps figures, to appear in PRB 1 Oct 199

Risks to the Human Rights Advocacy in African Constitutions

This article presents the results of a comparative legal study of the texts of the constitutions of African states with a view to identifying the rules that minimize human rights risks. The research is based on a dialectical approach to the disclosure of legal phenomena and processes using general scientific (systematic and logical methods, analysis and synthesis) and specific scientific methods. African constitutions, in comparison with the constitutions of other states, and in particular European ones, contain a disproportionately large number of rules formalizing special human rights institutions. Typically, these are special councils, human rights commissions (Egypt, Morocco, and Tunisia) or certain categories of the population (three in Egypt, three in Morocco, one in the Central African Republic). In Morocco and Equatorial Guinea, both the Mediator and the Public Defender are established, respectively. The relevance of the study is due to the strategic objectives of creating a secure human rights status of the state, as well as the need to find and update theoretical, methodological, and practical approaches to protecting the rights and freedoms of a human and a citizen. Considering the rules of the African constitutional model of minimizing risks to human right advocacy, objectively in terms of quantity and quality, are considered hyperbolic

Standard constitutional catalog of principles of judicial authority in the CIS countries

The present paper presents the results of a comparative legal analysis of constitutions of the CIS member states in order to identify a standard catalog of judicial power principles in them, considering their interpretation as a set of fundamental principles determining the institutional and procedural aspects of judicial powe