Quasi One Dimensional Systems
Mostrando 1-10 de 10 artigos, teses e dissertações.
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1. Localization of vibrational modes in low dimensional systems : an application to DNA / Localização de modos vibracionais em sistemas de baixa dimensionalidade : uma aplicação ao DNA
ln this work we studied the localization of vibrational modes of three simple models of DNA: unidimensional chain, double chain and the model of falir chains. ln these models, atomic groups were replaced by effective fiasses linked to each other by springs. For each model, the dynamic matrix was calculated and diagonalized obtaining the vibrational modes wit
Publicado em: 2009
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2. Current conservation in light front dynamics.
We adopt the quasi-potential method as a systematic tool to study relativistic composite systems projected at light-front global time hyperplanes. We address specifically the light-front projection of the Bethe-Salpeter equation for two-bosons, two-fermions and three-bosons systems. The quasi-potential formalism: i) provides a suitable framework for performi
Publicado em: 2007
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3. Structural and dynamical properties of a quasi-onedimensional classical binary system / Estudo das propriedades estruturais e dinÃmicas de um sistema binÃrio quasi-unidimensional.
The aim of this work is to study the structural and dynamical properties of a classical binary system of charged particles confined in a two dimensional channel. Such a system is described in the literature as quasi-unidimensional, and its relevance is supported by the possibility of technological applications, shown recently in the scientific literature, an
Publicado em: 2007
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4. Phonon spectra of disordered chains: an application to DNA
Recent developments in the field of nano-electronics have encouraged the study of quasi one dimensional systems such as DNA and its applications to new devices. In this work we use two models to explore the vibrational properties of DNA-like chains: a linear chain and two laterally coupled linear chains. In the former case, the disorder induces a diatomic be
Brazilian Journal of Physics. Publicado em: 2006-09
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5. Intersubband excitations at finite temperatures and their roles in different quasi-one-dimensional systems
We theoretically study many-body excitations in three different quasi-one-dimensional (Q1D) electron systems: (i) those formed on the surface of liquid Helium; (ii) in two coupled semiconductor quantum wires; and (iii) Q1D electrons embedded in polar semiconductor-based quantum wires. Our results show intersubband coupling between higher subbands and the two
Brazilian Journal of Physics. Publicado em: 2006-06
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6. O papel da interação elétron-elétron no regime Hall quântico interio.
Experimental and theoretical studies of the aspects of particle-like and collective behavior of electrons in the proximity of the edges of two-dimensional (2DES) and quasi-one-dimensional (Q1DES) systems, named quantum wires (QWs), in semiconductor heterostructures reveal the important role of the electron-electron interaction on the edge states in the integ
Publicado em: 2004
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7. Efeitos de desordem ou aperiodicidade sobre o comportamento de sistemas magnéticos / Effects of disorder or aperiodicity on the behavior of magnetic systems
Consideramos os efeitos de desordem ou aperiodicidade sobre três sistemas magnéticos distintos. Inicialmente, apresentamos um modelo fenomenológico para descrever a dependência térmica da magnetização remanente induzida por diluição numa classe de antiferromagnetos quase-unidimensionais. O modelo trata exatamente as correlações ao longo da direç�
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 04/10/2002
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8. Ballistic transport in semiconductor quantum wires in the presence of defects
We present calculations of the conductance in semiconductor quasi-one-dimensional systems using the Landauer formalism. We consider the effects on the transport properties inside semiconductor quantum waveguides of different shapes when a defect is located either in the wire region or in the quasi-two-dimensional region. We observe changes on the plateau's t
Brazilian Journal of Physics. Publicado em: 2002-06
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9. Estudo dos estados eletrônicos em sistemas quase-unidimensionais. / Study of electronic states in quasi-one-dimensional systems.
We have studied the electronic properties of two different quasi-one-dimensional systems solving self-consistently the Schrödinger and Poisson equation. The method we use to calculate the electronic levels is based on the solution of the time-dependent Schrödinger equation using the split-operator technique. In the first system we have studied, we present
Publicado em: 1997
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10. Hyperbolic almost periodic solutions and toroidal limit sets
We consider an almost periodic solution φ(t) of an autonomous differential equation x′ = f(x). Let k denote the topological dimension of the hull H(φ). By considering the linearized equation x′ = A(t)x alone [where A(t) is the Jacobian matrix of f evaluated along φ(t)], one can derive a sufficient condition in order that φ(t) be quasi-periodic and th