12,078 research outputs found
Quantum interference and entanglement induced by multiple scattering of light
We report on the effects of quantum interference induced by transmission of
an arbitrary number of optical quantum states through a multiple scattering
medium. We identify the role of quantum interference on the photon correlations
and the degree of continuous variable entanglement between two output modes. It
is shown that the effect of quantum interference survives averaging over all
ensembles of disorder and manifests itself as increased photon correlations
giving rise to photon anti-bunching. Finally, the existence of continuous
variable entanglement correlations in a volume speckle pattern is predicted.
Our results suggest that multiple scattering provides a promising way of
coherently interfering many independent quantum states of light of potential
use in quantum information processing.Comment: 5 pages including 4 figure
Nodal-to-nodeless superconducting order parameter in LaFeAsPO synthesized under high pressure
Similar to chemical doping, pressure produces and stabilizes new phases of
known materials, whose properties may differ greatly from those of their
standard counterparts. Here, by considering a series of LaFeAsPO
iron-pnictides synthesized under high-pressure high-temperature conditions, we
investigate the simultaneous effects of pressure and isoelectronic doping in
the 1111 family. Results of numerous macro- and microscopic technique
measurements, unambiguously show a radically different phase diagram for the
pressure-grown materials, characterized by the lack of magnetic order and the
persistence of superconductivity across the whole doping
range. This unexpected scenario is accompanied by a branching in the electronic
properties across , involving both the normal and superconducting
phases. Most notably, the superconducting order parameter evolves from nodal
(for ) to nodeless (for ), in clear contrast to other 1111
and 122 iron-based materials grown under ambient-pressure conditions.Comment: 9 pages, 7 figures, Suppl. materia
Intermittency in Two-Dimensional Turbulence with Drag
We consider the enstrophy cascade in forced two-dimensional turbulence with a
linear drag force. In the presence of linear drag, the energy wavenumber
spectrum drops with a power law faster than in the case without drag, and the
vorticity field becomes intermittent, as shown by the anomalous scaling of the
vorticity structure functions. Using a previous theory, we compare numerical
simulation results with predictions for the power law exponent of the energy
wavenumber spectrum and the scaling exponents of the vorticity structure
functions obtained in terms of the distribution of finite time
Lyapunov exponents. We also study, both by numerical experiment and theoretical
analysis, the multifractal structure of the viscous enstrophy dissipation in
terms of its R\'{e}nyi dimension spectrum and singularity spectrum
. We derive a relation between and , and discuss
its relevance to a version of the refined similarity hypothesis. In addition,
we obtain and compare theoretically and numerically derived results for the
dependence on separation of the probability distribution of
\delta_{\V{r}}\omega, the difference between the vorticity at two points
separated by a distance . Our numerical simulations are done on a grid.Comment: 18 pages, 17 figure
Twelve Channel Optical Fiber Connector Assembly: From Commercial Off the Shelf to Space Flight Use
The commercial off the shelf (COTS) twelve channel optical fiber MTP array connector and ribbon cable assembly is being validated for space flight use and the results of this study to date are presented here. The interconnection system implemented for the Parallel Fiber Optic Data Bus (PFODB) physical layer will include a 100/140 micron diameter optical fiber in the cable configuration among other enhancements. As part of this investigation, the COTS 62.5/125 microns optical fiber cable assembly has been characterized for space environment performance as a baseline for improving the performance of the 100/140 micron diameter ribbon cable for the Parallel FODB application. Presented here are the testing and results of random vibration and thermal environmental characterization of this commercial off the shelf (COTS) MTP twelve channel ribbon cable assembly. This paper is the first in a series of papers which will characterize and document the performance of Parallel FODB's physical layer from COTS to space flight worthy
Virginia Domestic Relations Handbook and Virginia Domestic Relations Case Finder
The Michie Company has released two publications dealing with the changing area of domestic relations law and which provide the busy Virginia practitioner with easy access to the areas within the field of family law practice and the relevant case authorities
A Systematic Survey of the Effects of Wind Mass Loss Algorithms on the Evolution of Single Massive Stars
Mass loss is a key uncertainty in the evolution of massive stars. Stellar
evolution calculations must employ parametric algorithms for mass loss, and
usually only include stellar winds. We carry out a parameter study of the
effects of wind mass loss on massive star evolution using the open-source
stellar evolution code MESA. We provide a systematic comparison of wind mass
loss algorithms for solar-metallicity, nonrotating, single stars in the initial
mass range of . We consider combinations drawn from two hot
phase algorithms, three cool phase algorithms, and two Wolf-Rayet algorithms.
We consider linear wind efficiency scale factors of , , and to
account for reductions in mass loss rates due to wind inhomogeneities. We find
that the initial to final mass mapping for each zero-age main-sequence (ZAMS)
mass has a uncertainty if all algorithm combinations and wind
efficiencies are considered. The ad-hoc efficiency scale factor dominates this
uncertainty. While the final total mass and internal structure of our models
vary tremendously with mass loss treatment, final observable parameters are
much less sensitive for ZAMS mass . This indicates that
uncertainty in wind mass loss does not negatively affect estimates of the ZAMS
mass of most single-star supernova progenitors from pre-explosion observations.
Furthermore, we show that the internal structure of presupernova stars is
sensitive to variations in both main sequence and post main-sequence mass loss.
We find that the compactness parameter varies by as much as
for a given ZAMS mass evolved with different wind efficiencies and mass
loss algorithm combinations. [abridged]Comment: Accepted for publication on A&A, 22 pages + 2 appendixes, 12 figures,
online input parameters available at https://stellarcollapse.org/renzo2017
and data at https://zenodo.org/record/292924#.WK0q2tWi6W
Polarized neutron channeling as a tool for the investigations of weakly magnetic thin films
We present and apply a new method to measure directly weak magnetization in
thin films. The polarization of a neutron beam channeling through a thin film
structure is measured after exiting the structure edge as a microbeam. We have
applied the method to a tri-layer thin film structure acting as a planar
waveguide for polarized neutrons. The middle guiding layer is a rare earth
based ferrimagnetic material TbCo5 with a low magnetization of about 20 mT. We
demonstrate that the channeling method is more sensitive than the specular
neutron reflection method
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