3,381 research outputs found
Spin Susceptibility in the Superconducting state of Ferromagnetic Superconductor UCoGe
In order to determine the superconducting paring state in the ferromagnetic
superconductor UCoGe, ^{59}Co NMR Knight shift, which is directly related to
the microscopic spin susceptibility, was measured in the superconducting state
under magnetic fields perpendicular to spontaneous magnetization axis:
^{59}K^{a, b}. ^{59}K^{a, b} shows to be constant, but does not decrease below
a superconducting transition. These behaviors as well as the invariance of the
internal field at the Co site in the superconducting state exclude the
spin-singlet pairing, and can be interpreted with the equal-spin pairing state
with a large exchange field along the c axis, which was studied by Mineev
[Phys. Rev. B 81, 180504 (2010)].Comment: 5 pages, 4 figures, to be appear in PR
Identification of SH ro-vibrational lines in R And
We report the identification of SH ro-vibrational lines in the
published high-resolution infrared spectrum of the S-type star, R And. This is
the first astronomical detection of this molecule. The lines show inverse
P-Cygni profiles, indicating infall motion of the molecular layer due to
stellar pulsation. A simple spherical shell model with a constant infall
velocity is adopted to determine the condition of the layer. It is found that a
single excitation temperature of 2200 K reproduces the observed line
intensities satisfactory. SH is located in a layer from 1.0 to ~1.1 stellar
radii, which is moving inward with a velocity of 9 km s-1. These results are
consistent with the previous measurements of CO transitions. The
estimated molecular abundance SH/H is 1x10^-7, consistent with a thermal
equilibrium calculation.Comment: 10 pages, 2 figures. Accepted for publication in ApJ Letter
Electromagnetic K+ production on the deuteron with hyperon recoil polarization
Photo- and electroproduction processes of K+ on the deuteron are investigated
theoretically. Modern hyperon-nucleon forces as well as an updated kaon
production operator on the nucleon are used. Sizable effects of the
hyperon-nucleon final state interaction are seen in various observables.
Especially the photoproduction double polarization observable C_z is shown to
provide a handle to distinguish different hyperon-nucleon force models.Comment: 4 pages, 7 eps-figures, talk given at the VII International
Conference on Hypernuclear and Strange Particle Physics, Torino, Italy,
October 23-27, 2000, to appear in the proceedings (Nucl. Phys. A
Preliminary Study on Chemical Figuring and Finishing of Sintered SiC Substrate Using Atmospheric Pressure Plasma
AbstractChemical figuring and finishing techniques using atmospheric pressure plasma were proposed for realizing damage free processing of a reaction sintered SiC substrate. Open-air type plasma chemical vaporization machining (PCVM) utilizing He based CF4/O2 mixture process gas demonstrated good linearity of the relationship between removal volume and plasma irradiation time which required in numerically controlled figuring. However, the surface roughness of the substrate processed by PCVM increased with an increase in removal depth by forming pores on the surface because etching rate of residual Si was about 3 times greater than that of SiC
Exact Ground States in Spin Systems with Orbital Degeneracy
We present exact ground states in spin models with orbital generacy in one
and higher dimensions. A method to obtain the exact ground states of the models
when the Hamiltonians are composed of the products of two commutable operators
is proposed. For the case of the spin-1/2 model with two-fold degeneracy some
exact ground states are given, such as the Valence-Bond (VB), the magnetically
ordered, and the orbitally ordered states under particular parameter regimes.
We also find the models with the higher spin and degeneracy which have the new
types of VB ground states in the spin and the orbital sectors.Comment: 4 pages(JPSJ.sty), 2 figures(EPS), to appear in J. Phys. Soc. Jpn.
68, No.2 (1999) 32
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