30,747 research outputs found
Improving the performance of inorganic-organic hybrid photovoltaic devices by uniform ordering of ZnO nanorods and near-atmospheric pressure nitrogen plasma treatment
Charmonium-Nucleon Dissociation Cross Sections in the Quark Model
Charmonium dissociation cross sections due to flavor-exchange
charmonium-baryon scattering are computed in the constituent quark model. We
present results for inelastic and scattering amplitudes
and cross sections into 46 final channels, including final states composed of
various combinations of , , , and . These results
are relevant to experimental searches for the deconfined phase of quark matter,
and may be useful in identifying the contribution of initial
production to the open-charm final states observed at RHIC through the
characteristic flavor ratios of certain channels. These results are also of
interest to possible charmonium-nucleon bound states.Comment: 10 pages, 5 eps figures, revte
On the sign of the pi-rho-omega coupling constant
It is shown that the relative sign between the and
coupling constants can be determined most sensitively from production
processes in collisions. Recent data on these reactions clearly favor the
sign of the coupling constant which is opposite to that
inferred from studies of the photoproduction reaction in combination with the
vector meson dominance assumption and used by many authors. Implication of this
finding in the description of other reactions is discussed.Comment: 6 pages, 4 figures, REVTeX, to be published in Phys. Lett.
Epitaxial aluminium-nitride tunnel barriers grown by nitridation with a plasma source
High critical current-density (10 to 420 kA/cm^2)
superconductor-insulator-superconductor tunnel junctions with aluminium nitride
barriers have been realized using a remote nitrogen plasma from an inductively
coupled plasma source operated in a pressure range of 10^{-3} to 10^{-1} mbar.
We find a much better reproducibility and control compared to previous work.
From the current-voltage characteristics and cross-sectional TEM images it is
inferred that, compared to the commonly used AlO_x barriers, the
poly-crystalline AlN barriers are much more uniform in transmissivity, leading
to a better quality at high critical current-densities.Comment: 3 pages, 3 figures, accepted for publication in AP
Coexistence of bulk and surface states probed by Shubnikov-de Haas oscillations in BiSe with high charge-carrier density
Topological insulators are ideally represented as having an insulating bulk
with topologically protected, spin-textured surface states. However, it is
increasingly becoming clear that these surface transport channels can be
accompanied by a finite conducting bulk, as well as additional topologically
trivial surface states. To investigate these parallel conduction transport
channels, we studied Shubnikov-de Haas oscillations in BiSe thin films,
in high magnetic fields up to 30 T so as to access channels with a lower
mobility. We identify a clear Zeeman-split bulk contribution to the
oscillations from a comparison between the charge-carrier densities extracted
from the magnetoresistance and the oscillations. Furthermore, our analyses
indicate the presence of a two-dimensional state and signatures of additional
states the origin of which cannot be conclusively determined. Our findings
underpin the necessity of theoretical studies on the origin of and the
interplay between these parallel conduction channels for a careful analysis of
the material's performance.Comment: Manuscript including supplemental materia
- …