2,327 research outputs found
Phase Transition and Monopoles Densities in a Nearest Neighbors Two-Dimensional Spin Ice Model
In this work, we show that, due to the alternating orientation of the spins
in the ground state of the artificial square spin ice, the influence of a set
of spins at a certain distance of a reference spin decreases faster than the
expected result for the long range dipolar interaction, justifying the use of
the nearest neighbor two dimensional square spin ice model as an effective
model. Using an extension of the model presented in ref. [Scientific Reports 5,
15875 (2015)], considering the influence of the eight nearest neighbors of each
spin on the lattice, we analyze the thermodynamics of the model and study the
monopoles and string densities dependence as a function of the temperature.Comment: 11 pages, 8 figure
Diamagnetic response of cylindrical normal metal - superconductor proximity structures with low concentration of scattering centers
We have investigated the diamagnetic response of composite NS proximity
wires, consisting of a clean silver or copper coating, in good electrical
contact to a superconducting niobium or tantalum core. The samples show strong
induced diamagnetism in the normal layer, resulting in a nearly complete
Meissner screening at low temperatures. The temperature dependence of the
linear diamagnetic susceptibility data is successfully described by the
quasiclassical Eilenberger theory including elastic scattering characterised by
a mean free path l. Using the mean free path as the only fit parameter we found
values of l in the range 0.1-1 of the normal metal layer thickness d_N, which
are in rough agreement with the ones obtained from residual resistivity
measurements. The fits are satisfactory over the whole temperature range
between 5 mK and 7 K for values of d_N varying between 1.6 my m and 30 my m.
Although a finite mean free path is necessary to correctly describe the
temperature dependence of the linear response diamagnetic susceptibility, the
measured breakdown fields in the nonlinear regime follow the temperature and
thickness dependence given by the clean limit theory. However, there is a
discrepancy in the absolute values. We argue that in order to reach
quantitative agreement one needs to take into account the mean free path from
the fits of the linear response. [PACS numbers: 74.50.+r, 74.80.-g]Comment: 10 pages, 9 figure
Estudo integrado de camucamu (Myrciaria dubia (H. B. K.) Mc Vaugh), frutífera amazônica: nova opção para a valorização econômica dos recursos naturais no Estado do Pará.
Desempenho de clones de batata-doce (Ipomoea batatas L.) no Submédio Vale do São Francisco.
Suplemento. Edição dos Anais do 52 Congresso Brasileiro de Olericultura, Salvador, jul. 2012
Coeficiente de determinação genotípica em acessos de camucamuzeiro ( Myrciaria dúbia (H. B. K.) Mc. Vaugh).
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Características produtivas cultivares de cenoura em sistema orgânico de cultivo no verão.
Este trabalho teve como objetivo avaliar o desempenho produtivo de cultivares de cenoura, sob cultivo orgânico, no verão, em Petrolina, PE.Suplemento. Edição dos Anais do 53 Congresso Brasileiro de Olericultura, jul. 2014
Coeficiente de determinação genotípica para caracteres quantitativos de onze acessos de camucamuzeiro.
Correlações fenotípicas entre caracteres morfológicos e de produção de palmito em pupunheira.
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