2,469 research outputs found
S wave superconductivity in newly discovered superconductor BaTiSbO revealed by Sb-NMR/Nuclear Quadrupole Resonance measurements
We report the Sb-NMR/nuclear quadrupole resonance (NQR)
measurements on the newly-discovered superconductor BaTiSbO with a
two-dimensional TiO square-net layer formed with Ti (3). NQR
measurements revealed that the in-plane four-fold symmetry is broken at the Sb
site below 40 K, without an internal field appearing at the Sb
site. These exclude a spin-density wave (SDW)/ charge density wave (CDW)
ordering with incommensurate correlations, but can be understood with the
commensurate CDW ordering at . The spin-lattice relaxation rate
, measured at the four-fold symmetry breaking site, decreases below
superconducting (SC) transition temperature , indicative of the
microscopic coexistence of superconductivity and the CDW/SDW phase below
. Furthermore, of Sb-NQR shows a coherence peak just
below and decreases exponentially at low temperatures. These
results are in sharp contrast with those in cuprate and iron-based
superconductors, and strongly suggest that its SC symmetry is classified to an
ordinary s-wave state.Comment: 5 pages, 6 figure
L^p boundedness of the wave operator for the one dimensional Schroedinger operator
Given a one dimensional perturbed Schroedinger operator H=-(d/dx)^2+V(x) we
consider the associated wave operators W_+, W_- defined as the strong L^2
limits as s-> \pm\infty of the operators e^{isH} e^{-isH_0} We prove that the
wave operators are bounded operators on L^p for all 1<p<\infty, provided
(1+|x|)^2 V(x) is integrable, or else (1+|x|)V(x) is integrable and 0 is not a
resonance. For p=\infty we obtain an estimate in terms of the Hilbert
transform. Some applications to dispersive estimates for equations with
variable rough coefficients are given.Comment: 26 page
Organometalic carbosilane polymers containing vanadium and their preparation
The present invention concerns a new organometallic polymer material containing in part a vanadium-siloxane linkage (V-0-Si), which has excellent resistance to heat and oxidation and a high residue ratio after high temperature treatment in a non-oxidizing atmosphere, for example, nitrogen, argon, helium, ammonia, or hydrogen
Method for producing heat-resistant semi-inorganic compounds
The method for producing a heat resistant, semi-inorganic compound is discussed. Five examples in which various alcohols, phenols, and aromatic carbonic acids are used to test heat resistance and solubility are provided
Inverse Scattering at a Fixed Quasi-Energy for Potentials Periodic in Time
We prove that the scattering matrix at a fixed quasi--energy determines
uniquely a time--periodic potential that decays exponentially at infinity. We
consider potentials that for each fixed time belong to in space. The
exponent 3/2 is critical for the singularities of the potential in space. For
this singular class of potentials the result is new even in the
time--independent case, where it was only known for bounded exponentially
decreasing potentials.Comment: In this revised version I give a more detailed motivation of the
class of potentials that I consider and I have corrected some typo
Dynamical formation of correlations in a Bose-Einstein condensate
We consider the evolution of bosons interacting with a repulsive short
range pair potential in three dimensions. The potential is scaled according to
the Gross-Pitaevskii scaling, i.e. it is given by . We
monitor the behavior of the solution to the -particle Schr\"odinger equation
in a spatial window where two particles are close to each other. We prove that
within this window a short scale interparticle structure emerges dynamically.
The local correlation between the particles is given by the two-body zero
energy scattering mode. This is the characteristic structure that was expected
to form within a very short initial time layer and to persist for all later
times, on the basis of the validity of the Gross-Pitaevskii equation for the
evolution of the Bose-Einstein condensate. The zero energy scattering mode
emerges after an initial time layer where all higher energy modes disperse out
of the spatial window. We can prove the persistence of this structure up to
sufficiently small times before three-particle correlations could develop.Comment: 36 pages, latex fil
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