63,620 research outputs found
Entanglement dynamics following a sudden quench: an exact solution
We present an exact and fully analytical treatment of the entanglement
dynamics for an isolated system of coupled oscillators following a sudden
quench of the system parameters. The system is analyzed using the solutions of
the time dependent Schrodinger's equation, which are obtained by solving the
corresponding nonlinear Ermakov equations. The entanglement entropies exhibit a
multi-oscillatory behaviour, where the number of dynamically generated time
scales increases with . The harmonic chains exhibit entanglement revival and
for larger values of , we find near-critical logarithmic scaling for
the entanglement entropy, which is modulated by a time dependent factor. The
case is equivalent to the two site Bose-Hubbard model in the tunneling
regime, which is amenable to empirical realization in cold atom systems.Comment: Figure for large N added, discussion related with near critical
scaling behavior adde
Thermodynamic properties of interstitial elements in the refractory metals Semiannual report, 1 Dec. 1968 - 31 May 1969
Carbon activity in refractory metal
Nanocrystallization and Amorphization Induced by Reactive Nitrogen Sputtering in Iron and Permalloy
Thin films of iron and permalloy Ni80Fe20 were prepared using an Ar+N2
mixture with magnetron sputtering technique at ambient temperature. The
nitrogen partial pressure, during sputtering process was varied in the range of
0 to 100%, keeping the total gas flow at constant. At lower nitrogen pressures
RN2<33% both Fe and NiFe, first form a nanocrystalline structure and an
increase in nitrogen partail pressure results in formation of an amorphous
structure. At intermediate nitrogen partial pressures, nitrides of Fe and NiFe
were obtained while at even higher nitrogen partial pressures, nitrides
themselves became nanocrystalline or amorphous. The surface, structural and
magnetic properties of the deposited films were studied using x-ray reflection
and diffraction, transmission electron microscopy, polarized neutron
reflectivity and using a DC extraction magnetometer. The growth behavior for
amorphous film was found different as compared with poly or nanocrystalline
films. The soft-magnetic properties of FeN were improved on nanocrystallization
while those of NiFeN were degraded. A mechanism inducing nanocrystallization
and amorphization in Fe and NiFe due to reactive nitrogen sputtering is
discussed in the present article.Comment: 13 Pages, 15 Figure
Radial flow has little effect on clusterization at intermediate energies in the framework of the Lattice Gas Model
The Lattice Gas Model was extended to incorporate the effect of radial flow.
Contrary to popular belief, radial flow has little effect on the clusterization
process in intermediate energy heavy-ion collisions except adding an ordered
motion to the particles in the fragmentation source. We compared the results
from the lattice gas model with and without radial flow to experimental data.
We found that charge yields from central collisions are not significantly
affected by inclusion of any reasonable radial flow.Comment: 8 pages, 2 figures, submitted to PRC; Minor update and resubmitted to
PR
The effect of the GLP-1 analogue Exenatide on functional connectivity within an NTS-based network in women with and without obesity.
ObjectiveThe differential effect of GLP-1 agonist Exenatide on functional connectivity of the nucleus tractus solitaries (NTS), a key region associated with homeostasis, and on appetite-related behaviours was investigated in women with normal weight compared with women with obesity.MethodsFollowing an 8-h fast, 19 female subjects (11 lean, 8 obese) participated in a 2-d double blind crossover study. Subjects underwent functional magnetic resonance imaging at fast and 30-min post subcutaneous injection of 5 μg of Exenatide or placebo. Functional connectivity was examined with the NTS. Drug-induced functional connectivity changes within and between groups and correlations with appetite measures were examined in a region of interest approach focusing on the thalamus and hypothalamus.ResultsWomen with obesity reported less hunger after drug injection. Exenatide administration increased functional connectivity of the left NTS with the left thalamus and hypothalamus in the obese group only and increased the correlation between NTS functional connectivity and hunger scores in all subjects, but more so in the obese.ConclusionsObesity can impact the effects of Exenatide on brain connectivity, specifically in the NTS and is linked to changes in appetite control. This has implications for the use of GLP-1 analogues in therapeutic interventions
Thermodynamic properties of interstitial elements in the refractory metals Progress report, 1 Jun. - 30 Nov. 1969
Thermodynamic properties of carbon in molybdenum and tungsten at solubility limi
Unveiling Magnetic Dipole Radiation in Phase-Reversal Leaky-Wave Antennas
published_or_final_versio
Phenomenology with Wilson fermions using smeared sources
We investigate the use of two types of non-local (``smeared'') sources for
quark propagators in quenched lattice QCD at using Wilson fermions
at and . We present results for the hadron mass spectrum,
meson decay constants, quark masses, the chiral condensate and the quark
distribution amplitude of the pion. The use of smeared sources leads to a
considerable improvement over previous results. We find a disturbing
discrepancy between the baryon spectra obtained using Wuppertal and wall
sources. We find good signals in the ratio of correlators used to calculate the
quark mass and the chiral condensate and show that the extrapolation to the
chiral limit is smooth.Comment: (revised), 57 pages (29 pages of PostScript in landscape mode, 765924
bytes
Magnetic Transition in the Kondo Lattice System CeRhSn2
Our resistivity, magnetoresistance, magnetization and specific heat data
provide unambiguous evidence that CeRhSn2 is a Kondo lattice system which
undergoes magnetic transition below 4 K.Comment: 3 pages text and 5 figure
Evolution of magnetism in Yb(Rh_(1-x)Co_x)2Si2
We present a study of the evolution of magnetism from the quantum critical
system YbRh2Si2 to the stable trivalent Yb system YbCo2Si2. Single crystals of
Yb(Rh_(1-x)Co_x)2Si2 were grown for 0 < x < 1 and studied by means of magnetic
susceptibility, electrical resistivity, and specific heat measurements, as well
as photoemission spectroscopy. The results evidence a complex magnetic phase
diagram, with a non-monotonic evolution of T_N and two successive transitions
for some compositions resulting in two tricritical points. The strong
similarity with the phase diagram of YbRh2Si2 under pressure indicates that Co
substitution basically corresponds to the application of positive chemical
pressure. Analysis of the data proves a strong reduction of the Kondo
temperature T_K with increasing Co content, T_K becoming smaller than T_N for x
~ 0.5, implying a strong localization of the 4f electrons. Furthermore,
low-temperature susceptibility data confirm a competition between ferromagnetic
and antiferromagnetic exchange. The series Yb(Rh_(1-x)Co_x)2Si2 provides an
excellent experimental opportunity to gain a deeper understanding of the
magnetism at the quantum critical point in the vicinity of YbRh2Si2 where the
antiferromagnetic phase disappears (T_N=>0).Comment: 11 pages, 9 figure
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