Thermodynamics of symmetric spin--orbital model: One- and two-dimensional cases

The specific heat and susceptibilities for the two- and one-dimensional spin--orbital models are calculated in the framework of a spherically symmetric self-consistent approach at different temperatures and relations between the parameters of the system. It is shown that even in the absence of the long-range spin and orbital order, the system exhibits the features in the behavior of thermodynamic characteristics, which are typical of those manifesting themselves at phase transitions. Such features are attributed to the quantum entanglement of the coupled spin and orbital degrees of freedom.Comment: 7 pages, 9 figures, submitted to JETP Letter

Electrical resistivity, hall coefficient, and thermopower of optimally doped high-T c superconductors

© 2014, Pleiades Publishing, Inc. For a two-dimensional optimally doped antiferromagnet with spin S =1/2, we study the temperature dependence of the electrical resistivity ρ(T), Hall coefficient RH(T), and thermopower Q(T). The temperature dependence corresponding to optimally doped layered high-Tc superconducting cuprates has been obtained simultaneously for all three transport coefficients within the unified spin-polaron approach for the Kondo lattice. The key features of our study are the usage of the multimoment method for solving the kinetic equations (seven moments for the nonequilibrium distribution function ensure a good convergence) and the form of ac spin susceptibility χ(q, ω) for localized spins. For χ(q, ω), we choose a self-consistent expression which takes into account the “crossover” between the spin susceptibility determined by the self-consistent spherically symmetric Green’s function method and the semiphenomenological spin susceptibility corresponding to the critical decay of magnons

Neutrino scattering on polarized electron target as a test of neutrino magnetic moment

We suggest to use a polarized electron target for improving the sensitivity of the search for the neutrino magnetic moment to the level $\sim 3\cdot10^{-13}\mu_B$ in the processes of neutrino (antineutrino) -- electron scattering. It is shown that in this case the weak interaction term in the total cross section is significantly suppressed comparing with unpolarized case, but the electromagnetic term does not depend on electron polarization.Comment: 11 pages, LaTeX2e, using elsart.cls and epsf.sty, 3 postscript figures. Accepted in Phys. Lett.

Referees Court as an Alternative Way of Settlement of Disputes in the Sphere of Business: History and Present

In the article, problems of activity of the referees courts on the example of Ancient Rome and its current state are considered. For our country the referees courts — rather new system of solving of economic disputes. Now activity of the referees courts is subject to criticism from business community and demands further improvement. One of the main advantages of transfer to the referees court of the arisen dispute is its faster consideration. Nevertheless, now the number of appeals to the referees courts are not enough. The low authority of institute of the referees courts and low awareness of citizens on advantages of referees trial is the main reason of this circumstance. Transformation of the referees court into full-fledged institute of protection of the rights and legitimate interests of representatives of a business community is a priority task for society and the state

Historical and Legal Aspect of Consideration by the Courts of the Pskov Region of Citizens’ Complaints in the Economic Sphere at the Final Stage of the History of the Soviet State

The purpose of this article is to study the process of development and functioning of the judicial institutions of the Pskov region at one of the turning points in the history of our country on the eve of the collapse of the Soviet Union and the formation of a sovereign Russian state. In the context of the socio-political and economic reforms of the Perestroika period, the judicial system did not remain aloof from the new trends in state policy. The content and main directions of the implementation of judicial policy in the field of civil rights are changing. Radical changes in the life of the country were reflected in the activities of the judicial authorities of the Pskov region regarding the work with citizens’ complaints on economic issues

From underdoped to overdoped cuprates: two quantum phase transitions

Several experimental and theoretical studies indicate the existence of a critical point separating the underdoped and overdoped regions of the high-T_c cuprates' phase diagram. There are at least two distinct proposals on the critical concentration and its physical origin. First one is associated with the pseudogap formation for p<p*, with p~0.2. Another one relies on the Hall effect measurements and suggests that the critical point and the quantum phase transition (QPT) take place at optimal doping, p_{opt}~0.16. Here we have performed a precise density of states calculation and found that there are two QPTs and the corresponding critical concentrations associated with the change of the Fermi surface topology upon doping