2,795 research outputs found
Kohn anomalies in momentum dependence of magnetic susceptibility of some three-dimensional systems
We study a question of presence of Kohn points, yielding at low temperatures
non-analytic momentum dependence of magnetic susceptibility near its maximum,
in electronic spectum of some three-dimensional systems. In particular, we
consider one-band model on face centered cubic lattice with hopping between
nearest and next-nearest neighbors, which models some aspects of the dispersion
of ZrZn, and the two-band model on body centered cubic lattice, modeling
the dispersion of chromium. For the former model it is shown that Kohn points
yielding maxima of susceptibility exist in a certain (sufficiently wide) region
of electronic concentrations; the dependence of the wave vectors, corresponding
to the maxima, on the chemical potential is investigated. For the two-band
model we show existence of the lines of Kohn points, yielding maximum of the
susceptibility, which position agrees with the results of band structure
calculations and experimental data on the wave vector of antiferromagnetism of
chromium.Comment: 13 pages, 9 figures. JETP, in press (2017
Translation model, translation analysis, translation strategy: an integrated methodology
AbstractThe paper revisits the concepts of translation model, translation analysis, and translation strategy from an integrated perspective. Translation modeling is reconsidered in terms of a paradigm shift and a distinction between a process-oriented (descriptive) model and an action-oriented (prescriptive) model. Following the discourse and communication translation model, we put forward a “model – analysis – strategy” concept and a “features – difficulties – solutions” concept to reformulate a translation strategy as a flexible, variable and, to a certain extent, individual (but not unique) algorithm. We also introduce the notion of a discursive profile framed on existing discourse-related data in translation
Physics Reach of High-Energy and High-Statistics IceCube Atmospheric Neutrino Data
This paper investigates the physics reach of the IceCube neutrino detector
when it will have collected a data set of order one million atmospheric
neutrinos with energies in the 0.1 \sim 10^4 TeV range. The paper consists of
three parts. We first demonstrate how to simulate the detector performance
using relatively simple analytic methods. Because of the high energies of the
neutrinos, their oscillations, propagation in the Earth and regeneration due to
\tau decay must be treated in a coherent way. We set up the formalism to do
this and discuss the implications. In a final section we apply the methods
developed to evaluate the potential of IceCube to study new physics beyond
neutrino oscillations. Not surprisingly, because of the increased energy and
statistics over present experiments, existing bounds on violations of the
equivalence principle and of Lorentz invariance can be improved by over two
orders of magnitude. The methods developed can be readily applied to other
non-conventional physics associated with neutrinos.Comment: 21 pages, 7 figures, Revtex
Hybridization and spin-orbit coupling effects in quasi-one-dimensional spin-1/2 magnet Ba3Cu3Sc4O12
We study electronic and magnetic properties of the quasi-one-dimensional
spin-1/2 magnet Ba3Cu3Sc4O12 with a distinct orthogonal connectivity of CuO4
plaquettes. An effective low-energy model taking into account spin-orbit
coupling was constructed by means of first-principles calculations. On this
basis a complete microscopic magnetic model of Ba3Cu3Sc4O12, including
symmetric and antisymmetric anisotropic exchange interactions, is derived. The
anisotropic exchanges are obtained from a distinct first-principles numerical
scheme combining, on one hand, the local density approximation taking into
account spin-orbit coupling, and, on the other hand, projection procedure along
with the microscopic theory by Toru Moriya. The resulting tensors of the
symmetric anisotropy favor collinear magnetic order along the structural chains
with the leading ferromagnetic coupling J1 = -9.88 meV. The interchain
interactions J8 = 0.21 meV and J5 = 0.093 meV are antiferromagnetic. Quantum
Monte Carlo simulations demonstrated that the proposed model reproduces the
experimental Neel temperature, magnetization and magnetic susceptibility data.
The modeling of neutron diffraction data reveals an important role of the
covalent Cu-O bonding in Ba3Cu3Sc4O12.Comment: 11 pages, 12 figure
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