6,381 research outputs found
Coupling Between An Optical Phonon and the Kondo Effect
We explore the ultra-fast optical response of Yb_{14}MnSb_{11}, providing
further evidence that this Zintl compound is the first ferromagnetic,
under-screened Kondo lattice. These experiments also provide the first
demonstration of coupling between an optical phonon mode and the Kondo effect.Comment: 4 Pages, 3 Figures, submitted to Phys. Rev. Let
A high flux source of cold strontium atoms
We describe an experimental apparatus capable of achieving a high loading
rate of strontium atoms in a magneto-optical trap operating in a high vacuum
environment. A key innovation of this setup is a two dimensional
magneto-optical trap deflector located after a Zeeman slower. We find a loading
rate of 6x10^9/s whereas the lifetime of the magnetically trapped atoms in the
3P2 state is 54s.Comment: 12 pages, 16 figure
Effects of multi-stage dehumidified-air drying on the polyphenol content of Hydrocotyle bonariensis
Traditional drying methods involve high temperatures that degrade heat-sensitive compounds. Dehumidified-air drying, an alternative to traditional drying methods, is suitable for heat-sensitive compounds; however, it consumes a large amount of energy and is comparatively expensive. In this study, a multi-chamber dehumidified-air dryer was designed to dry Hydrocotyle bonariensis, and the retention of the polyphenol content of Hydrocotyle bonariensis under various drying conditions was examined. Multi-chamber dehumidified-air drying involves two chambers; each chamber was operated at temperatures of 30, 40, and 50°C with air volumetric flow rates of 30 and 50 L/min. The results indicated that the highest retention of total phenolic content and total flavonoid content, 24.67 mg of GAE/g dry weight (DW) and 2.204 mg of catechin/g DW, respectively, was obtained at 50°C with a 50 L/min air flow rate in the first drying chamber. Multi-stage dehumidified-air dryers have the potential to dry heat-sensitive products with reduced energy consumption
Affleck-Dine baryogenesis in inflating curvaton scenario with O(TeV) mass moduli curvaton
We study the Affleck-Dine (AD) baryogenesis in the inflating curvaton
scenario, when the curvaton is a moduli field with O(TeV) mass. A
moduli field with such mass is known to be free from the Polonyi problem, and
furthermore its decay products can explain the present cold dark matter
abundance. In our scenario, it further explains the primordial curvature
perturbation and the present baryon density all together. The current
observational bound on the baryon isocurvature perturbation, which severely
constrains the AD baryogenesis with the original oscillating moduli curvaton
scenario, is shown to put practically negligible constraint if we replace the
oscillating curvaton with the inflating curvaton.Comment: 1+21pages v2: minor correction v3: included short reviews, added
refs, fixed typo
2-[3,5-Bis(4-fluorophenyl)-4,5-dihydro-1H-pyrazol-1-yl]-4,6-bis(4-fluorophenyl)pyrimidine
In the title compound, C31H20F4N4, the pyrazole ring adopts an envelope conformation and forms a dihedral angle of 9.91 (6)° with the adjacent pyrimidine ring. The pyrimidine ring forms dihedral angles of 9.23 (6) and 2.16 (5)° with its adjacent fluoro-substituted benzene rings, whereas these angles are 88.22 (6) and 9.66 (6)° for the pyrazole ring and its adjacent benzene rings. In the crystal, molecules are linked by C—H⋯F hydrogen bonds into ribbons along [01-1]. The crystal packing is further stabilized by C—H⋯π and by π–π interactions, with centroid–centroid distances of 3.7428 (7) and 3.7630 (6) Å
On the cause and extent of outer radiation belt losses during the 30 September 2012 dropout event
Abstract On 30 September 2012, a flux dropout occurred throughout Earth\u27s outer electron radiation belt during the main phase of a strong geomagnetic storm. Using eight spacecraft from NASA\u27s Time History of Events and Macroscale Interactions during Substorms (THEMIS) and Van Allen Probes missions and NOAA\u27s Geostationary Operational Environmental Satellites constellation, we examined the full extent and timescales of the dropout based on particle energy, equatorial pitch angle, radial distance, and species. We calculated phase space densities of relativistic electrons, in adiabatic invariant coordinates, which revealed that loss processes during the dropout were \u3e 90% effective throughout the majority of the outer belt and the plasmapause played a key role in limiting the spatial extent of the dropout. THEMIS and the Van Allen Probes observed telltale signatures of loss due to magnetopause shadowing and subsequent outward radial transport, including similar loss of energetic ring current ions. However, Van Allen Probes observations suggest that another loss process played a role for multi-MeV electrons at lower L shells (L\u3c ∼4). Key Points Dropout events can encompass the entire outer radiation belt Dropouts can result in \u3e90% losses and be a hard reset on the system Loss at L \u3e ∼4 is dominated by MP shadowing and outward transport
Field-angle Dependence of the Zero-Energy Density of States in the Unconventional Heavy-Fermion Superconductor CeCoIn5
Field-angle dependent specific heat measurement has been done on the
heavy-fermion superconductor CeCoIn5 down to ~ 0.29 K, in a magnetic field
rotating in the tetragonal c-plane. A clear fourfold angular oscillation is
observed in the specific heat with the minima (maxima) occurring along the
[100] ([110]) directions. Oscillation persists down to low fields H << Hc2,
thus directly proving the existence of gap nodes. The results indicate that the
superconducting gap symmetry is most probably of dxy type.Comment: 8 pages, 3 figures, to be published in J. Phys. Condens. Matte
Composite-fermion crystallites in quantum dots
The correlations in the ground state of interacting electrons in a
two-dimensional quantum dot in a high magnetic field are known to undergo a
qualitative change from liquid-like to crystal-like as the total angular
momentum becomes large. We show that the composite-fermion theory provides an
excellent account of the states in both regimes. The quantum mechanical
formation of composite fermions with a large number of attached vortices
automatically generates omposite fermion crystallites in finite quantum dots.Comment: 5 pages, 3 figure
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