3,275 research outputs found
Electron Correlation Driven Heavy-Fermion Formation in LiV2O4
Optical reflectivity measurements were performed on a single crystal of the
d-electron heavy-fermion (HF) metal LiV2O4. The results evidence the highly
incoherent character of the charge dynamics for all temperatures above T^*
\approx 20 K. The spectral weight of the optical conductivity is redistributed
over extremely broad energy scales (~ 5 eV) as the quantum coherence of the
charge carriers is recovered. This wide redistribution is, in sharp contrast to
f-electron Kondo lattice HF systems, characteristic of a metallic system close
to a correlation driven insulating state. Our results thus reveal that strong
electronic correlation effects dominate the low-energy charge dynamics and
heavy quasiparticle formation in LiV2O4. We propose the geometrical
frustration, which limits the extension of charge and spin ordering, as an
additional key ingredient of the low-temperature heavy-fermion formation in
this system.Comment: 5 pages, 3 figure
Development of Health Literacy from Activities of Culture, Leisure, and Sports
Living in a healthy and independent manner would be beneficial for people. Health literacy can be obtained through activities of culture, leisure, and sports. Authors have been involved in sports medicine, music, and management of International Masters Athletics Federation(IMAF). Health literacy would be a dynamic multi-dimensional perspective that combines various kinds of health-related matter, information, and activity. It can be developed through the activities of sports and music. These opportunities are divided into scheduled care healthcare programs and unexpected human interaction with various participants together. The latter would be a synergistic effect in multi-dimensional aspects
Evaluation of the Family-to-Family Homelessness Prevention Project: Final Report (January 1, 2011-October 31, 2013)
This report describes implementation of the Homelessness Prevention Project of the Family-to-Family Program in Boston over nearly three years: January 1, 2011 and October 31, 2013. The project intended to help families to avoid imminent loss of their housing units. It selected participants that had good prospects for long-term housing and income stability. Project staff thought that modest financial assistance plus case management would enable these families to regain and perhaps even improve their personal and economic circumstances. The Oak Foundation provided major financial support for the project.
The report describes the administration of the project, and then examines the characteristics of all of the participant families at the time of enrollment compared to the screening criteria established by the program. It then explores the experiences of participant families after they received their grant awards. It gives special attention to the experiences of those that received final grant awards 12 or more months before September 30, 2013.
The report draws on data provided to the evaluation team by three agencies that administered the grants. It also describes findings from in-depth interviews with 12 families who received assistance from the program and interviews with representatives of the Family-to Family program and the three agencies that distributed funds and provided case management (HomeStart, Project Hope, and Travelers’ Aid/Family Aid)
Optical conductivity in the CuO double chains of PrBa_2Cu_4O_8: Consequences of charge fluctuation
We calculate the optical conductivity of the CuO double chains of
PrBaCuO by the mean-field approximation for the coupled two-chain
Hubbard model around quarter filling. We show that the 40 meV peak
structure, spectral shape, and small Drude weight observed in experiment are
reproduced well by the present calculation provided that the stripe-type charge
ordering presents. We argue that the observed anomalous optical response may be
due to the presence of stripe-type fluctuations of charge carriers in the CuO
double chains; the fast time scale of the optical measurement should enable one
to detect slowly fluctuating order parameters as virtually a long-range order.Comment: 7 pages, 5 eps figure
Effects of carbon incorporation on doping state of YBa2Cu3Oy
Effects of carbon incorporation on the doping state of YBa2Cu3Oy (Y-123) were
investigated. Quantitative carbon analysis revealed that carbon could be
introduced into Y-123 from both the precursor and the sintering gas. Nearly
carbon-free (< 200 ppm) samples were prepared from a vacuum-treated precursor
by sintered at 900 ˚C and cooling with 20 ˚C /min in flowing oxygen
gas. The lower Tc (= 88 K) and higher oxygen content (y = 6.98) strongly
suggested the overdoping state, which was supported by the temperature
dependence of resisitivity and thermoelectric power. The nuclear quadrapole
resonance spectra and the Raman scattering spectra indicated that there was
almost no oxygen defect in the Cu-O chain in these samples. On the other hand,
in the same cooling condition, the samples sintered in air stayed at optimal
doping level with Tc = 93 K, and the intentionally carbon-doped sample was in
the underdoping state. It is revealed that about 60% of incorporated carbon was
substituted for Cu at the chain site in the form of CO32+, and the rest remains
at the grain boundary as carbonate impurities. Such incorporation affected the
oxygen absorption process in Y-123. It turned out that the oxygen content in
Y-123 cannot be controlled only by the annealing temperature and the oxygen
partial pressure but also by the incorporated carbon concentration.Comment: 16pages, 9figure
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