6,130 research outputs found
Domain wall description of superconductivity
In the present work we shall address the issue of electrical conductivity in
superconductors in the perspective of superconducting domain wall solutions in
the realm of field theory. We take our set up made out of a dynamical complex
scalar field coupled to gauge field to be responsible for superconductivity and
an extra scalar real field that plays the role of superconducting domain walls.
The temperature of the system is interpreted through the fact that the soliton
following accelerating orbits is a Rindler observer experiencing a thermal
bath.Comment: 9 pages, 5 figures, Latex. Version to appear in PL
Cosmology in the Universe with distance dependent Lorentz-violating bakground
We consider a cosmological setup with the inflaton field in the presence of a
redshift dependent Lorentz-violating time-like background to address the
inflationary regime and other phases of the Universe. We also show that the
regime of dark energy at large distances (low redshifts) is essentially
dominated by the presence of the Lorentz-violating background.Comment: 8 pages, no figure, Latex, to appear in AHE
Qualidade do leite armazenado em tanques coletivos.
Importância da refrigeração do leite ; Tanques coletivos; Pesquisa sobre a qualidade do leite de tanques coletivos; Uma segunda pesquisa: maio de 2007 a junho de 2008.bitstream/item/65295/1/CT-99-Qualid-leite-armaz-tanq-coletivos.pd
Magnetic states of linear defects in graphene monolayers: effects of strain and interaction
The combined effects of defect-defect interaction and of uniaxial or biaxial
strains of up to 10\% on the development of magnetic states on the
defect-core-localized quasi-one-dimensional electronic states generated by the
so-called 558 linear extended defect in graphene monolayers are investigated by
means of {\it ab initio} calculations. Results are analyzed on the basis of the
heuristics of the Stoner criterion. We find that conditions for the emergence
of magnetic states on the 558 defect can be tuned by uniaxial tensile parallel
strains (along the defect direction) at both limits of isolated and interacting
558 defects. Parallel strains are shown to lead to two cooperative effects that
favor the emergence of itinerant magnetism: enhancement of the DOS of the
resonant defect states in the region of the Fermi level and tuning of the Fermi
level to the maximum of the related DOS peak. A perpendicular strain is
likewise shown to enhance the DOS of the defect states, but it also effects a
detunig of the Fermi level that shifts away from the maximum of the DOS of the
defect states, which inhibts the emergence of magnetic states. As a result,
under biaxial strains the stabilization of a magnetic state depends on the
relative magnitudes of the two components of strain.Comment: 9 pages 8 figure
- …