4,361 research outputs found
Parity oscillations of Kondo temperature in a single molecule break junction
We study the Kondo temperature () of a single molecule break junction.
By employing a numerical renormalization group calculations we have found that
depends dramatically upon the position of the molecule in the wire formed
between the contacts. We show that exhibits strong \emph{oscillations}
when the parity of the left {and/or} right number of atomic sites ()
is changed. For a given set of parameters, the maximum value of occurs
for () combination, while its minimum values is observed for
().
These oscillations are fully understood in terms of the effective
hybridization function.Comment: 4 pages, 5 figure
Galactic Nonlinear Dynamic Model
We develop a model for spiral galaxies based on a nonlinear realization of
the Newtonian dynamics starting from the momentum and mass conservations in the
phase space. The radial solution exhibits a rotation curve in qualitative
accordance with the observational data.Comment: 6 pages, 1 figure. Talk given in the 7th Alexander Friedmann
International Seminar, June 29 to July 5, 2008, Joao Pessoa, PB, Brazi
Quantum Double Models coupled with matter: an algebraic dualisation approach
In this paper, we constructed a new generalization of a class of discrete
bidimensional models, the so called Quantum Double Models, by introduce matter
qunits to the faces of the lattice that supports these models. This new
generalization can be interpreted as the algebraic dual of a first, where we
introduce matter qunits to the vertices of this same lattice. By evaluating the
algebraic and topological orders of these new models, we prove that, as in the
first generalization, a new phenomenon of quasiparticle confinement may appear
again: this happens when the co-action homomorphism between matter and gauge
groups is non-trivial. Consequently, this homomorphism not only classifies the
different models that belong to this new class, but also suggests that they can
be interpreted as a 2-dimensional restriction of the 2-lattice gauge theories.Comment: 18 pages, 8 figures; submitted to publicatio
Qualidade de pimentões produzidos em sistema orgãnico e armazenados com e sem refrigeração.
O objetivo deste trabalho foi selecionar e avaliar a qualidade de pimentões de 14 cultivares provenientes da coleção da Embrapa Hortaliças
Finite-group gauge theories on lattices as Hamiltonian systems with constraints
In this work, we present a brief but insightful overview of the gauge
theories, which are defined on -dimensional lattices by using finite gauge
groups, in order to show how they can be interpreted as a Hamiltonian system
with constraints, analogous to what happens with the classical (continuous)
gauge (field) theories. As this interpretation is not usually explored in the
literature that discusses/introduces the concept of lattice gauge theory, but
some recent works have been exploring Hamiltonian models in order to support
some kind of quantum computation, we use this interpretation to, for example,
present a brief geometric view of one class of these models: the Kitaev Quantum
Double Models.Comment: 22 pages, 5 figures; submitted to publicatio
Sustentabilidade do manejo orgânico e convencional na produção de hortaliças do Distrito Federal.
bitstream/item/75723/1/ct-49.pd
Uso de calda bordalesa, extratos vegetais e biofertilizante para controle de doenças foliares do tomateiro em sistema orgânico de produção.
Avaliou-se o efeito de produtos alternativos no controle de doenças foliares do tomateiro em experimentos em casa de vegetação e no campo em sistema orgânico de produção.bitstream/item/73755/1/bpd-82.pd
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