17,967 research outputs found
Insulator-to-metal transition in sulfur-doped silicon
We observe an insulator-to-metal (I-M) transition in crystalline silicon
doped with sulfur to non- equilibrium concentrations using ion implantation
followed by pulsed laser melting and rapid resolidification. This I-M
transition is due to a dopant known to produce only deep levels at equilibrium
concentrations. Temperature-dependent conductivity and Hall effect measurements
for temperatures T > 1.7 K both indicate that a transition from insulating to
metallic conduction occurs at a sulfur concentration between 1.8 and 4.3 x
10^20 cm-3. Conduction in insulating samples is consistent with variable range
hopping with a Coulomb gap. The capacity for deep states to effect metallic
conduction by delocalization is the only known route to bulk intermediate band
photovoltaics in silicon.Comment: Submission formatting; 4 journal pages equivalen
Sub-monolayer nucleation and growth of complex oxide heterostructures at high supersaturation and rapid flux modulation
We report on the non-trivial nanoscale kinetics of the deposition of novel
complex oxide heterostructures composed of a unit-cell thick correlated metal
LaNiO3 and dielectric LaAlO3. The multilayers demonstrate exceptionally good
crystallinity and surface morphology maintained over the large number of
layers, as confirmed by AFM, RHEED, and synchrotron X-ray diffraction. To
elucidate the physics behind the growth, the temperature of the substrate and
the deposition rate were varied over a wide range and the results were treated
in the framework of a two-layer model. These results are of fundamental
importance for synthesis of new phases of complex oxide heterostructures.Comment: 13 pages, 6 figure
Boundary K-matrices and the Lax pair for 1D open XYZ spin-chain
We analysis the symmetries of the reflection equation for open model
and find their solutions case by case. In the general open boundary
conditions, the Lax pair for open one-dimensional spin-chain is given.Comment: LaTeX, 17 pages, errors in references correcte
Production and optical properties of liquid scintillator for the JSNS experiment
The JSNS (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron
Source) experiment will search for neutrino oscillations over a 24 m short
baseline at J-PARC. The JSNS inner detector will be filled with 17 tons
of gadolinium-loaded liquid scintillator (LS) with an additional 31 tons of
unloaded LS in the intermediate -catcher and outer veto volumes.
JSNS has chosen Linear Alkyl Benzene (LAB) as an organic solvent because
of its chemical properties. The unloaded LS was produced at a refurbished
facility, originally used for scintillator production by the RENO experiment.
JSNS plans to use ISO tanks for the storage and transportation of the LS.
In this paper, we describe the LS production, and present measurements of its
optical properties and long term stability. Our measurements show that storing
the LS in ISO tanks does not result in degradation of its optical properties.Comment: 7 pages, 4 figures
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