7,025 research outputs found
Berry Phase Quantum Thermometer
We show how Berry phase can be used to construct an ultra-high precision
quantum thermometer. An important advantage of our scheme is that there is no
need for the thermometer to acquire thermal equilibrium with the sample. This
reduces measurement times and avoids precision limitations.Comment: Updated to published version. I. Fuentes previously published as I.
Fuentes-Guridi and I. Fuentes-Schulle
Management of incidentally detected heart murmurs in dogs and cats
A dog or a cat has an incidentally detected heart murmur if the murmur is an unexpected discovery during a veterinary consultation that was not initially focused on the cardiovascular system. This document presents approaches for managing dogs and cats that have incidentally-detected heart murmurs, with an emphasis on murmur characteristics, signalment profiling, and multifactorial decision-making to choose an optimal course for a given patient
Consequences of spontaneous reconnection at a two-dimensional non-force-free current layer
Magnetic neutral points, where the magnitude of the magnetic field vanishes
locally, are potential locations for energy conversion in the solar corona. The
fact that the magnetic field is identically zero at these points suggests that
for the study of current sheet formation and of any subsequent resistive
dissipation phase, a finite beta plasma should be considered, rather than
neglecting the plasma pressure as has often been the case in the past. The
rapid dissipation of a finite current layer in non-force-free equilibrium is
investigated numerically, after the sudden onset of an anomalous resistivity.
The aim of this study is to determine how the energy is redistributed during
the initial diffusion phase, and what is the nature of the outward transmission
of information and energy. The resistivity rapidly diffuses the current at the
null point. The presence of a plasma pressure allows the vast majority of the
free energy to be transferred into internal energy. Most of the converted
energy is used in direct heating of the surrounding plasma, and only about 3%
is converted into kinetic energy, causing a perturbation in the magnetic field
and the plasma which propagates away from the null at the local fast
magnetoacoustic speed. The propagating pulses show a complex structure due to
the highly non-uniform initial state. It is shown that this perturbation
carries no net current as it propagates away from the null. The fact that,
under the assumptions taken in this paper, most of the magnetic energy released
in the reconnection converts internal energy of the plasma, may be highly
important for the chromospheric and coronal heating problem
Consumer Confidence in the Food System, Media Coverage and Stock Prices of Food Companies: A Regression Analysis
A series of recent and serious food safety incidents have generated a national debate over the significant costs that they impose on various stakeholders - consumers, industry, or the government. This paper examines the impact of media coverage of food safety and defense issues on consumer confidence in food safety, and measures the response of stock prices of food companies to changes in consumer confidence. Results show that, increases in media coverage have a negative impact on consumer confidence, and that decreases in the levels of consumer confidence on food safety have a negative impact on stock prices of food companies, in particular for the larger firms. These findings confirm that the financial performance of food the industry is negatively affected by category-specific food safety events, and the effects of media coverage on consumer confidence in the safety of the food system.Agribusiness, Food Consumption/Nutrition/Food Safety,
Topological Features in Ion Trap Holonomic Computation
Topological features in quantum computing provide controllability and noise
error avoidance in the performance of logical gates. While such resilience is
favored in the manipulation of quantum systems, it is very hard to identify
topological features in nature. This paper proposes a scheme where holonomic
quantum gates have intrinsic topological features. An ion trap is employed
where the vibrational modes of the ions are coherently manipulated with lasers
in an adiabatic cyclic way producing geometrical holonomic gates. A crucial
ingredient of the manipulation procedures is squeezing of the vibrational
modes, which effectively suppresses exponentially any undesired fluctuations of
the laser amplitudes, thus making the gates resilient to control errors.Comment: 9 pages, 4 figures, REVTE
Continuous variable entanglement sharing in non-inertial frames
We study the distribution of entanglement between modes of a free scalar
field from the perspective of observers in uniform acceleration. We consider a
two-mode squeezed state of the field from an inertial perspective, and
analytically study the degradation of entanglement due to the Unruh effect, in
the cases of either one or both observers undergoing uniform acceleration. We
find that for two observers undergoing finite acceleration, the entanglement
vanishes between the lowest frequency modes. The loss of entanglement is
precisely explained as a redistribution of the inertial entanglement into
multipartite quantum correlations among accessible and unaccessible modes from
a non-inertial perspective. We show that classical correlations are also lost
from the perspective of two accelerated observers but conserved if one of the
observers remains inertial.Comment: 19 pages, 13 EPS figures (most low-res due to oversize); terminology
revise
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