325 research outputs found
Classification of one-dimensional quasilattices into mutual local-derivability classes
One-dimensional quasilattices are classified into mutual local-derivability
(MLD) classes on the basis of geometrical and number-theoretical
considerations. Most quasilattices are ternary, and there exist an infinite
number of MLD classes. Every MLD class has a finite number of quasilattices
with inflation symmetries. We can choose one of them as the representative of
the MLD class, and other members are given as decorations of the
representative. Several MLD classes of particular importance are listed. The
symmetry-preserving decorations rules are investigated extensively.Comment: 42 pages, latex, 5 eps figures, Published in JPS
Universalities in One-electron Properties of Limit Quasi-periodic Lattices
We investigate one-electron properties of one-dimensional self-similar
structures called limit quasi-periodic lattices. The trace map of such a
lattice is nonconservative in contrast to the quasi-periodic case, and we can
determine the structure of its attractor. It allows us to obtain the three new
features of the present system: 1) The multi-fractal characters of the energy
spectra are {\it universal}. 2) The supports of the -spectra extend
over the whole unit interval, . 3) There exist marginal critical
states.Comment: 4 pages, 2figure
Sound modes broadening for Fibonacci one dimensional quasicrystals
We investigate vibrational excitation broadening in one dimensional Fibonacci
model of quasicrystals (QCs). The chain is constructed from particles with two
masses following the Fibonacci inflation rule. The eigenmode spectrum depends
crucially on the mass ratio. We calculate the eigenstates and eigenfunctions.
All calculations performed self-consistently within the regular expansion over
the three wave coupling constant. The approach can be extended to three
dimensional systems. We find that in the intermediate range of mode coupling
constants, three-wave broadening for the both types of systems (1D Fibonacci
and 3D QCs) depends universally on frequency. Our general qualitative
conclusion is that for a system with a non-simple elementary cell phonon
spectrum broadening is always larger than for a system with a primitive cell
(provided all other characteristics are the same).Comment: 2o pages, 15 figure
Binary self-similar one-dimensional quasilattices: Mutual local-derivability classification and substitution rules
Self-similar binary one-dimensional (1D) quasilattices (QLs) are classified
into mutual local-derivability (MLD) classes. It is shown that the MLD
classification is closely related to the number-theoretical classification of
parameters which specify the self-similar binary 1D QLs. An algorithm to derive
an explicit substitution rule, which prescribes the transformation of a QL into
another QL in the same MLD class, is presented. An explicit inflation rule,
which prescribes the transformation of the self-similar 1D QL into itself, is
obtained as a composition of the explicit substitution rules. Symmetric
substitution rules and symmetric inflation rules are extensively discussed.Comment: 24 pages, 4 figures, submitted to PR
Continuum elastic sphere vibrations as a model for low-lying optical modes in icosahedral quasicrystals
The nearly dispersionless, so-called "optical" vibrational modes observed by
inelastic neutron scattering from icosahedral Al-Pd-Mn and Zn-Mg-Y
quasicrystals are found to correspond well to modes of a continuum elastic
sphere that has the same diameter as the corresponding icosahedral basic units
of the quasicrystal. When the sphere is considered as free, most of the
experimentally found modes can be accounted for, in both systems. Taking into
account the mechanical connection between the clusters and the remainder of the
quasicrystal allows a complete assignment of all optical modes in the case of
Al-Pd-Mn. This approach provides support to the relevance of clusters in the
vibrational properties of quasicrystals.Comment: 9 pages without figure
Electronic Theory for the Transition from Fermi-Liquid to Non-Fermi-Liquid Behavior in High-T Superconductors
We analyze the breakdown of Fermi-liquid behavior within the 2D Hubbard model
as function of doping using our recently developed numerical method for the
self consistent summation of bubble and ladder diagrams. For larger doping
concentrations the system behaves like a conventional Fermi-liquid and for
intermediate doping similar to a marginal Fermi-liquid. However, for smaller
doping pronounced deviations from both pictures occur which are due to the
increasing importance of the short range antiferromagnetic spin fluctuations.
This is closely related to the experimental observed shadow states in the
normal state of high- superconductors. Furthermore, we discuss the
implications of our results for transport experiments.Comment: 11 pages (REVTeX) with 4 figures (Postscript
Diacylglycerol kinase zeta inhibits G alpha q-induced atrial remodeling in transgenic mice
ArticleHEART RHYTHM. 6(1):78-84 (2009)journal articl
Phonon and magnon scattering of antiferromagnetic Bi2Fe4O9
The phonon structure of antiferromagnetic Bi2Fe4O9 (space group Pbnm No. 55, TN≈240 K) was studied theoretically by calculations of lattice dynamics and experimentally between 10 and 300 K by polarized Raman spectroscopy. Most of the 12Ag+12B1g+9B2g+9B3g Raman modes were unambiguously identified. Strong second-order scattering was observed for ab-plane-confined incident and scattered light polarizations. In addition to the phonon-scattering, broad Raman bands with typical characteristics of magnon scattering appear below TN. The magnon bands are analyzed on the basis of magnetic structure of Bi2Fe4O9 and attributed to two- magnon excitations
Equipments for Neutron Induced Experiments by Using a Monoenergetic Neutron Beam
開始ページ、終了ページ: 冊子体のページ付
Two-dimensional XY spin/gauge glasses on periodic and quasiperiodic lattices
Via Monte Carlo studies of the frustrated XY or classical planar model we
demonstrate the possibility of a finite (nonzero) temperature spin/gauge glass
phase in two dimensions. Examples of both periodic and quasiperiodic two
dimensional lattices, where a high temperature paramagnetic phase changes to a
spin/gauge glass phase with the lowering of temperature, are presented. The
existence of the spin/gauge glass phase is substantiated by our study of the
temperature dependence of the Edwards-Anderson order parameter, spin glass
susceptibility, linear susceptibility and the specific heat. Finite size
scaling analysis of spin glass susceptibility and order parameter yields a
nonzero critical temperature and exponents that are in close agreement with
those obtained by Bhatt and Young in their random Ising model study
on a square lattice. These results suggest that certain periodic and
quasiperiodic two-dimensional arrays of superconducting grains in suitably
chosen transverse magnetic fields should behave as superconducting glasses at
low temperatures.Comment: RevTex, 25 pages. 11 epsf figures available upon request
([email protected] or [email protected]). Submitted
to Phys. Rev.
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