8,272 research outputs found
High probability state transfer in spin-1/2 chains: Analytical and numerical approaches
This article is devoted to the development of analytical and numerical
approaches to the problem of the end-to-end quantum state transfer along the
spin-1/2 chain using two methods: (a) a homogeneous spin chain with week end
bonds and equal Larmor frequencies and (b) a homogeneous spin chain with end
Larmor frequencies different from inner ones. A tridiagonal matrix
representation of the XY Hamiltonian with nearest neighbor interactions
relevant to the quantum state transfer is exactly diagonalized for a
combination of the above two methods. In order to take into account
interactions of the remote spins we used numerical simulations of the quantum
state transfer in ten-node chains. We compare the state transfer times obtained
using the two above methods for chains governed by the both XY and XXZ
Hamiltonians and using both nearest neighbor and all node interactions.Comment: 16 pages, 5 figure
The effect of electron surface scattering on fine metal particle electromagnetic radiation absorption
The magnetic dipole absorption cross section of a spherically shaped metal
particle was calculated in terms of kinetic approach. The particle considered
was placed in the field of a plane electromagnetic wave. The model of boundary
conditions was investigated taking into account the dependence of the
reflectivity coefficient both on the surface roughness parameter and on the
electron incidence angle. The results obtained were compared with theoretical
computation results for a model of combined diffusion-specular boundary
conditions of Fuchs.Comment: 9 pages, 5 figure
Mega-clusters as a tool of interregional cooperation in tourists field
In order to diversify the Russian economy, it is necessary to pay great attention to the emerging sectors of the economy; with a systemic approach they are able to reveal their accumulated potential. Authors consider one of such industries to be the sphere of tourism. Russia has its own unique natural-recreational and cultural-historical potential, which is not fully utilized, and it is confirmed with the relevant statistics. The authors propose to accelerate the development of tourism by raising the level of interregional cooperation from the position of using coexisting competition and competitive coexistence in tourist mega-clusters. Due to the lack of financial resources for separate regions for the tourism development, the implementation of this approach is effective, as it allows achieving savings of money due to economies of scale. The phenomena of coexisting competition and competitive coexistence in the tourism sphere presuppose the unification of the different regions authorities’ efforts for the joint implementation of projects. Regions joining forces on the basis of coexisting competition and competitive coexistence within the mega-clusters will allow each administrative-territorial unit to develop and improve its competitive advantage by asking a stimulus to the development of the other participants. This approach makes it possible to obtain other positive effects noted in the study. Thus, findings broaden the knowledge about the phenomena of coexisting competition and competitive coexistence in the regional economy, about mega-clusters as tools for interregional interactions in the tourism sphere
The Power Flow Angle of Acoustic Waves in Thin Piezoelectric Plates
The curves of slowness and power flow angle (PFA) of quasi-antisymmetric (A0) and quasi-symmetric (S0) Lamb waves as well as quasi-shear-horizontal (SH0) acoustic waves in thin plates of lithium niobate and potassium niobate of X-,Y-, and Z-cuts for various propagation directions and the influence of electrical shorting of one plate surface on these curves and PFA have been theoretically investigated. It has been found that the group velocity of such waves does not coincide with the phase velocity for the most directions of propagation. It has been also shown that S0 and SH0 wave are characterized by record high values of PFA and its change due to electrical shorting of the plate surface in comparison with surface and bulk acoustic waves in the same material. The most interesting results have been verified by experiment. As a whole, the results obtained may be useful for development of various devices for signal processing, for example, electrically controlled acoustic switchers
Identification of the byproducts of the oxygen evolution reaction on rutile-type oxides under dynamic conditions
Peer reviewedPostprin
Determinant Line Bundles and Topological Invariants of Hyperbolic Geometry - Expository Remarks
We give some remarks on twisted determinant line bundles and Chern-Simons
topological invariants associated with real hyperbolic manifolds. Index of a
twisted Dirac operator is derived. We discuss briefly application of obtained
results in topological quantum field theory.Comment: 10 pages. To appear in G@C, special issue devoted to QG, Unified
Models and Strings, to mark 100th Anniversary of Tomsk State Pedagogical
University. Editor - S.D. Odintso
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