447 research outputs found
A Framework for Tracking the Impacts of the Affordable Care Act in California
Recommends measures for monitoring the impact of healthcare reform on insurance coverage, affordability and comprehensiveness of coverage, and access to care; the best data source for each measure; gaps in existing data; and issues for data presentation
Health Insurance Exchanges: How Economic and Financial Modeling Can Support State Implementation
Outlines considerations for modeling the impact of state health insurance exchanges on states, including size and number of exchanges; demographics, health status, and health costs of the newly covered; and extent of collaboration with other states
Role of CuO chains in vortex core structure in YBa2Cu3O{7-delta}
The Bogoliubov-deGennes equations are solved for a proximity model for
YBa_2Cu_3O_{7-\delta} in a magnetic field. The model explicitly includes the
effects of the one-dimensional CuO chains, whose influence on the vortex core
structure is studied. The rapid vortex core contraction as a function of field
which is seen experimentally at low magnetic fields is naturally explained by
the presence of the chains.Comment: 9 pages, 5 figure
On the interpretation of muon-spin-rotation experiments in the mixed state of type-II superconductors
We argue that claims about magnetic field dependence of the magnetic field
penetration depth lambda, which were made on the basis of moun-spin-rotation
studies of some superconductors, originate from insufficient accuracy of
theoretical models employed for the data analysis. We also reanalyze some of
already published experimental data and demonstrate that numerical calculations
of Brandt [E.H. Brandt, Phys. Rev. B 68, 54506 (2003)] may serve as a reliable
and powerful tool for the analysis of the data collected in experiments with
conventional superconductors. Furthermore, one can use this approach in order
to distinguish between conventional and unconventional superconductors. It is
unfortunate that these calculations have practically never been employed for
such analyses.Comment: 24 pages, 10figure
High-field muSR studies of superconducting and magnetic correlations in cuprates above Tc
The advent of high transverse-field muon spin rotation (TF-muSR) has led to
recent muSR investigations of the magnetic-field response of cuprates above the
superconducting transition temperature T_c. Here the results of such
experiments on hole-doped cuprates are reviewed. Although these investigations
are currently ongoing, it is clear that the effects of high field on the
internal magnetic field distribution of these materials is dependent upon a
competition between superconductivity and magnetism. In La_{2-x}Sr_xCuO_4 the
response to the external field above Tc is dominated by heterogeneous spin
magnetism. However, the magnetism that dominates the observed inhomogeneous
line broadening below x ~ 0.19 is overwhelmed by the emergence of a completely
different kind of magnetism in the heavily overdoped regime. The origin of the
magnetism above x ~ 0.19 is currently unknown, but its presence hints at a
competition between superconductivity and magnetism that is reminiscent of the
underdoped regime. In contrast, the width of the internal field distribution of
underdoped YBa_2Cu_3O_y above Tc is observed to track Tc and the density of
superconducting carriers. This observation suggests that the magnetic response
above Tc is not dominated by electronic moments, but rather inhomogeneous
fluctuating superconductivity.Comment: 28 pages, 11 figures, 104 reference
On the Magnetic-Field Dependence of the Longitudinal Ultrasonic Attenuation in a Type-II Superconductor
We propose a simple method by which we can explain the magnetic-field
dependence of the longitudinal ultrasonic attenuation in a type-II
superconductor. It gives a curve which is in good agreement with experimental
data, in paticular, near the lower critical field H_c1. We compare it with
conventional methods, which is not in good agreement with the experimental data
near H_c1 but near the upper critical field H_c2.Comment: 7 pages, 2 figure
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