6,604 research outputs found
Tunable temperature induced magnetization jump in a GdVO3 single crystal
We report a novel feature of the temperature induced magnetization jump
observed along the a-axis of the GdVO3 single crystal at temperature TM = 0.8
K. Below TM, the compound shows no coercivity and remanent magnetization
indicating a homogenous antiferromagnetic structure. However, we will
demonstrate that the magnetic state below TM is indeed history dependent and it
shows up in different jumps in the magnetization only when warming the sample
through TM. Such a magnetic memory effect is highly unusual and suggesting
different domain arrangements in the supposedly homogenous antiferromagnetic
phase of the compound.Comment: 17 pages, 8 Figure
Observation of the Presuperfluid Regime in a Two-Dimensional Bose Gas
In complementary images of coordinate-space and momentum-space density in a
trapped 2D Bose gas, we observe the emergence of pre-superfluid behavior. As
phase-space density increases toward degenerate values, we observe a
gradual divergence of the compressibility from the value predicted by
a bare-atom model, . grows to 1.7 before
reaches the value for which we observe the sudden emergence of a spike
at in momentum space. Momentum-space images are acquired by means of a 2D
focusing technique. Our data represent the first observation of non-meanfield
physics in the pre-superfluid but degenerate 2D Bose gas.Comment: Replace with the version appeared in PR
Impact of the various spin and orbital ordering processes on multiferroic properties of orthovanadate DyVO3
The orthovanadate DyVO3 crystal, known to exhibit multiple structural, spin
and orbital ordering transitions, is presently investigated on the basis of
magnetization, heat capacity, resistivity, dielectric and polarization
measurements. Our main result is experimental evidence for the existence of
multiferroicity below a high TC of 108 K over a wide temperature range
including different spin-orbital ordered states. The onset of ferroelectricity
is found to coincide with the antiferromagnetic C-type spin ordering transition
taking place at 108 K, which indicates that DyVO3 belongs to type II
multiferroics exhibiting a coupling between magnetism and ferroelectricity.
Some anomalies detected on the temperature dependence of electric polarization
are discussed with respect to the nature of the spin-orbital ordered states of
the V sublattice and the degree of spin alignment in the Dy sublattice. The
orthovanadates RVO3 (R = rare earth or Y) form an important new category for
searching for high-TC multiferroics.Comment: 25 pages, 7 figures, 68 references, one supplementary material,
Physical Review B, Published 23 July 201
The Final Fate of Binary Neutron Stars: What Happens After the Merger?
The merger of two neutron stars usually produces a remnant with a mass
significantly above the single (nonrotating) neutron star maximum mass. In some
cases, the remnant will be stabilized against collapse by rapid, differential
rotation. MHD-driven angular momentum transport eventually leads to the
collapse of the remnant's core, resulting in a black hole surrounded by a
massive accretion torus. Here we present simulations of this process. The
plausibility of generating short duration gamma ray bursts through this
scenario is discussed.Comment: 3 pages. To appear in the Proceedings of the Eleventh Marcel
Grossmann Meeting, Berlin, Germany, 23-29 July 2006, World Scientific,
Singapore (2007
Uncertainties of predictions from parton distribution functions II: the Hessian method
We develop a general method to quantify the uncertainties of parton
distribution functions and their physical predictions, with emphasis on
incorporating all relevant experimental constraints. The method uses the
Hessian formalism to study an effective chi-squared function that quantifies
the fit between theory and experiment. Key ingredients are a recently developed
iterative procedure to calculate the Hessian matrix in the difficult global
analysis environment, and the use of parameters defined as components along
appropriately normalized eigenvectors. The result is a set of 2d Eigenvector
Basis parton distributions (where d=16 is the number of parton parameters) from
which the uncertainty on any physical quantity due to the uncertainty in parton
distributions can be calculated. We illustrate the method by applying it to
calculate uncertainties of gluon and quark distribution functions, W boson
rapidity distributions, and the correlation between W and Z production cross
sections.Comment: 30 pages, Latex. Reference added. Normalization of Hessian matrix
changed to HEP standar
EXPLORING THE SUPPLY OF SAFER FOODS: A CASE STUDY OF OYSTER DEPURATION IN DIXIE AND LEVY COUNTIES, FLORIDA
Shellfish depuration, economic feasibility, restaurant, consumer acceptance, Food Consumption/Nutrition/Food Safety,
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