563 research outputs found
Thermal entanglement of spins in a nonuniform magnetic field
We study the effect of inhomogeneities in the magnetic field on the thermal
entanglement of a two spin system. We show that in the ferromagnetic case a
very small inhomogeneity is capable to produce large values of thermal
entanglement. This shows that the absence of entanglement in the ferromagnetic
Heisenberg system is highly unstable against inhomogeneoity of magnetic fields
which is inevitably present in any solid state realization of qubits.Comment: 14 pages, 7 figures, latex, Accepted for publication in Physical
Review
Quantum Entanglement in Fermionic Lattices
The Fock space of a system of indistinguishable particles is isomorphic (in a
non-unique way) to the state-space of a composite i.e., many-modes, quantum
system. One can then discuss quantum entanglement for fermionic as well as
bosonic systems. We exemplify the use of this notion -central in quantum
information - by studying some e.g., Hubbard,lattice fermionic models relevant
to condensed matter physics.Comment: 4 Pages LaTeX, 1 TeX Figure. Presentation improved, title changed. To
appear in PR
Current state of the art and use case description on geofencing for traffic management
This report is a result of a literature review and document gathering focused on geofence use cases specific for road traffic management. It presents geofence use cases that are trialled or to be trialled, implemented use cases, as well as conceptual and potential future use cases, showing for which type of transport they are used and how geofence zones are applied or to be applied. The report was conducted in the project GeoSence â Geofencing strategies for implementation in urban traffic management and planning. It is a Joint programme initiative (JPI) Urban Europe project funded by European UnionÂŽs Horizon 2020, under ERA-NET Cofund Urban Accessibility and Connectivity and gather project partners from Germany, Norway, Sweden and UK. The goal is to present the current state of art, and describe use cases, based on the working definition of geofencing in the project, where geofence is defined as a virtual geographically located boundary, statically or dynamically defined. The study shows that for implemented and real-traffic trial use case, geofencing has been applied within private car transport, shared micro-mobility, freight and logistics, public bus transportation and ridesourcing. For the future use cases, geofencing has been tested or conceptually developed also for automated vehicles and shared automated mobility, among others. The report summarises main use cases and find them to answering to especially four challenges in traffic management: safety, environment, efficiency, and tracking and data collection. Some of the use cases however answer to several of these challenges, such as differentiated road charging, and the use cases in micro-mobility. Further, the system and functionality of the trialled and/or implemented use cases, show different types of regulation geofence use cases can be used for, from informing, assisting, full enforcement, incentivising and penalisation. Guidelines and recommendations so far form national authorities show that the existence of joint regulation or guidelines for the use of geofencing for different use cases is low â with some exceptions. Digital representation of traffic regulation will be crucial for enabling geofencing
Teleportation via thermally entangled state of a two-qubit Heisenberg XX chain
We find that quantum teleportation, using the thermally entangled state of
two-qubit Heisenberg XX chain as a resource, with fidelity better than any
classical communication protocol is possible. However, a thermal state with a
greater amount of thermal entanglement does not necessarily yield better
fidelity. It depends on the amount of mixing between the separable state and
maximally entangled state in the spectra of the two-qubit Heisenberg XX model.Comment: 5 pages, 1 tabl
Signal-background separation and energy reconstruction of gamma rays using pattern spectra and convolutional neural networks for the Small-Sized Telescopes of the Cherenkov Telescope Array
Imaging Atmospheric Cherenkov Telescopes (IACTs) detect very high-energy
gamma rays from ground level by capturing the Cherenkov light of the induced
particle showers. Convolutional neural networks (CNNs) can be trained on IACT
camera images of such events to differentiate the signal from the background
and to reconstruct the energy of the initial gamma ray. Pattern spectra provide
a 2-dimensional histogram of the sizes and shapes of features comprising an
image and they can be used as an input for a CNN to significantly reduce the
computational power required to train it. In this work, we generate pattern
spectra from simulated gamma-ray and proton images to train a CNN for
signal-background separation and energy reconstruction for the Small-Sized
Telescopes (SSTs) of the Cherenkov Telescope Array (CTA). A comparison of our
results with a CNN directly trained on CTA images shows that the pattern
spectra-based analysis is about a factor of three less computationally
expensive but not able to compete with the performance of the CTA images-based
analysis. Thus, we conclude that the CTA images must be comprised of additional
information not represented by the pattern spectra.Comment: 10 pages, 9 figures, submitted to Nuclear Instruments and Methods in
Physics Research - section
Global entanglement in multiparticle systems
We define a polynomial measure of multiparticle entanglement which is
scalable, i.e., which applies to any number of spin-1/2 particles. By
evaluating it for three particle states, for eigenstates of the one dimensional
Heisenberg antiferromagnet and on quantum error correcting code subspaces, we
illustrate the extent to which it quantifies global entanglement. We also apply
it to track the evolution of entanglement during a quantum computation.Comment: 9 pages, plain TeX, 1 PostScript figure included with epsf.tex
(ignore the under/overfull \vbox error messages); for related work see
http://math.ucsd.edu/~dmeyer/research.html or
http://www.math.ucsd.edu/~nwallach
Natural Thermal and Magnetic Entanglement in 1D Heisenberg Model
We investigate the entanglement between any two spins in a one dimensional
Heisenberg chain as a function of temperature and the external magnetic field.
We find that the entanglement in an antiferromagnetic chain can be increased by
increasing the temperature or the external field. Increasing the field can also
create entanglement between otherwise disentangled spins. This entanglement can
be confirmed by testing Bell's inequalities involving any two spins in the
solid.Comment: 4 pages, 5 figure
Early diverging insect-pathogenic fungi of the order entomophthorales possess diverse and unique subtilisin-like serine proteases
Insect-pathogenic fungi use subtilisin-like serine proteases (SLSPs) to degrade chitin-associated proteins in the insect procuticle. Most insect-pathogenic fungi in the order Hypocreales (Ascomycota) are generalist species with a broad host-range, and most species possess a high number of SLSPs. The other major clade of insect-pathogenic fungi is part of the subphylum Entomophthoromycotina (Zoopagomycota, formerly Zygomycota) which consists of high host-specificity insect-pathogenic fungi that naturally only infect a single or very few host species. The extent to which insect-pathogenic fungi in the order Entomophthorales rely on SLSPs is unknown. Here we take advantage of recently available transcriptomic and genomic datasets from four genera within Entomophthoromycotina: the saprobic or opportunistic pathogens Basidiobolus meristosporus, Conidiobolus coronatus, C. thromboides, C. incongruus, and the host-specific insect pathogens Entomophthora muscae and Pandora formicae, specific pathogens of house flies (Muscae domestica) and wood ants (Formica polyctena), respectively. In total 154 SLSP from six fungi in the subphylum Entomophthoromycotina were identified: E. muscae (n = 22), P. formicae (n = 6), B. meristosporus (n = 60), C. thromboides (n = 18), C. coronatus (n = 36), and C. incongruus (n = 12). A unique group of 11 SLSPs was discovered in the genomes of the obligate biotrophic fungi E. muscae, P. formicae and the saprobic human pathogen C. incongruus that loosely resembles bacillopeptidase F-like SLSPs. Phylogenetics and protein domain analysis show this class represents a unique group of SLSPs so far only observed among Bacteria, Oomycetes and early diverging fungi such as Cryptomycota, Microsporidia, and Entomophthoromycotina. This group of SLSPs is missing in the sister fungal lineages of Kickxellomycotina and the fungal phyla Mucoromyocta, Ascomycota and Basidiomycota fungi suggesting interesting gene loss patterns
Interleukin-18 Is a Strong Predictor of Cardiovascular Events in Elderly Men With the Metabolic Syndrome: Synergistic effect of inflammation and hyperglycemia
OBJECTIVEâThe aim of this study was to investigate the role of inflammatory markers as potential predictors of cardiovascular events in subjects with and without the metabolic syndrome
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