Electron Phonon Interaction
Mostrando 1-12 de 19 artigos, teses e dissertações.
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1. Estudo da interação elétron-fônon em nanotubos de carbono por Espectroscopia Raman Ressonante
In this work, we have used resonance Raman spectroscopy to the study of carbon nanotubes. We reviewed the literature concerning their structural, electronic and vibrational properties, emphasizing the role of many-body effects, particularly the electron-phonon interaction, on the latter two properties. We also reviewed how Raman spectroscopy can be applied t
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 01/09/2009
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2. Influência da radiação gama em filmes de PPV e PTHT: caracterização óptica e elétrica
In this work, we investigated the effects of Gamma ionizing radiation on optical properties of the polyeletrolite poly (chloride Tetrahydrothiophen of xililideno) (PTHT) and the conjugated polymer poly(p- phenylene vinileno) (PPV). The PPV films were processed from PTHT films and it was submitted on the annealing step at low (110oC) and higher (200oC) under
Publicado em: 2009
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3. Propriedades física de molécilas orgânicas e compostos do tipo perovskita CdSiO3 e CaPbO3
In the first part of this work our concern was to investigate the thermal effects in organic crystals using the theory of the polarons. To analyse such effect, we used the Fröhlichs Hamiltonian, that describes the dynamics of the polarons, using a treatment based on the quantum mechanics, to elucidate the electron-phonon interaction. Many are the forms to a
Publicado em: 2009
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4. Interação plasmon-fônon LO em superredes semicondutoras
This work presents a Raman investigation of the optical vibrations in highly doped In-GaAs/InP and GaAs/AlGaAs superlattices (SLs). The InGaAs/InP SLs grown with different periods were analyzed using polarized Raman techniques. No Raman selection rules were found in the long period InGaAs/InP SLs due to the structural defects in the bulk materials constituti
Publicado em: 2008
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5. PROPRIEDADES DE TRANSPORTE DE SISTEMAS NANOSCÓPICOS: ÁTOMOS E MOLÉCULAS / TRANSPORT PROPERTIES OF NANOSCOPIC SYSTEMS: ATOMS AND MOLECULES
In this work we study the electronic transport in atomic and molecular structures. By using the Green´s function method, we address the problem of the electron-electron and electron-phonon interactions and their effects on the conductance of the system. We present a detailed study of the regime where these two interactions are simultaneously important and s
Publicado em: 2007
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6. DC electric field effects on the electron dynamics in double rectangular quantum dots
The effect of a dc electric field on the temporal evolution of an electron in a double rectangular quantum dot is explored in this work. In the framework of the effective mass approximation, first-order scattering rates for interaction between confined electron-''free'' electron and electron-longitudinal acoustic phonon at room temperature are calculated in
Brazilian Journal of Physics. Publicado em: 2006-09
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7. The effects of the plasmon-LO phonon interaction on the critical densities of RPA approach in a quasi-one-dimensional system
In this work we have studied the electron LO phonon interaction on the pair-correlation function g(x) and its dependence on the electronic density for a GaAs-AlGaAs rectangular quantum wire within the random-phase approximation (RPA). We assumed two different values of the wire width. As negative non-physical results are found for lower electronic densities
Brazilian Journal of Physics. Publicado em: 2006-06
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8. A cinética ultra-rápida de excitações elementares em semicondutores fotoexcitados
In this work it is introduced some results of the studies of kinetic evolution to the equilibrium state of a photo-excited semiconductors. The equations of transistors that describes the evolution to the equilibrium was obtained through the Statistics Operator Method of not-equilibrium in Zubarev version. The semiconductor is described in terms of having a c
Publicado em: 2006
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9. The effect of polar and many-body interactions on the optical properties of III-nitrides / Estudo dos efeitos polares e de muitos corpos nas propriedades opticas de III-nitretos
Neste trabalho realizamos um estudo pormenorizado das propriedades ópticas de semicondutores polares de gap direto dopado tipo n.Em particular nos concentramos nos efeitos de muitos corpos (interação coulombiana)e na in .uência da interação elétron fônon LO (potencial de Fröhlich)sobre as propriedades ópticas do sistema. Para tanto,inicialmente,cal
Publicado em: 2005
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10. Electron spin-phonon relaxation in quantum dots
We calculate the spin relaxation rates in parabolic quantum dots due to the phonon modulation of the spin-orbit interaction in presence of an external magnetic field. Both, deformation potential (DP) and piezoelectric (PE) electron-phonon couplings are included in the Pavlov-Firsov spin-phonon Hamiltonian. We demonstrate that the spin relaxation rates are pa
Brazilian Journal of Physics. Publicado em: 2004-06
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11. Thermal expansion contribution to the temperature dependence of excitonic transitions in GaAs and AlGaAs
Photoluminescence and photoreflectance measurements have been used to determine excitonic transitions in the ternary Al xGa1-xAs alloy in the temperature range from 2 to 300 K. The effect of the thermal expansion contribution on the temperature dependence of excitonic transitions for different aluminum concentrations in the Al xGa1-xAs alloy is presented. Re
Brazilian Journal of Physics. Publicado em: 2004-06
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12. Electron-phonon interaction in electronic tunneling: from sequential rate equations to a coherent description
We discuss the main theoretical approaches for the phonon-assisted tunneling in double barrier resonant tunneling devices and introduce a quantum coherent treatment based on the mapping of the many-body problem into a higher dimensional one-body system. Conditions for a maximized phonon-emission are established.
Brazilian Journal of Physics. Publicado em: 2002-06