Quantum Wire
Mostrando 1-12 de 18 artigos, teses e dissertações.
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1. Estudo das propriedades termoelétricas de fios quânticos de telureto de chumbo / Study of thermoelectrical properties in lead telluride quantum wires
This work presents a theoretical study of the electronic and thermoelectric properties of PbTe quantum wires. Thermoelectric effects in nanostructured materials of IV-VI family, in particular superlattices, quantum well and quantum wire, have been studied a lot, because they present an enhancement in figure of merit relatively to bulk. Researching theoretica
Publicado em: 2010
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2. Prorpiedades de transportes em fios e poÃos quÃnticos. / Transport Properties of Quantum Wells and Quantum Wires
Materiais semicondutores sÃo os principais responsÃveis pelo grande crescimento da indÃstria eletrÃnica e pelo surgimento de novas tecnologias. A criaÃÃo de heteroestruturas possibilitou um grande impulso à fÃsica do estado sÃlido. Atualmente, o estudo de semicondutores està concentrado em sistemas de dimensionalidade reduzida, como os poÃos, fios
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 21/07/2009
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3. Hydrogenic impurity in ridge quantum wire
The binding energies as well as wave functions of hydrogenic impurities located in V-groove GaAs/Al xGa1-xAs quantum wires are calculated for different positions of the impurity inside the wires. The variational method is used and the carrier ground states are analytically calculated by an effective potential scheme together with a suitable coordinate transf
Brazilian Journal of Physics. Publicado em: 2006-12
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4. Hydrostatic pressure and electric-field effects on the shallow donor impurity states in GaAs-Ga0.7Al0.3As quantum-well wires
Using a variational procedure within the effective-mass approximation, we have made a theoretical study of the effects of hydrostatic pressure and applied electric fields on the binding energy of a shallow-donor impurity in square-transversal section GaAs-Ga0.7Al0.3As quantum-well wires. The electric field is applied in a plane of the transversal section of
Brazilian Journal of Physics. Publicado em: 2006-09
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5. Kondo and Fano effect in side attached double quantum-dot molecule
Electron tunneling through a double quantum dot molecule side attached to a quantum wire, in the Kondo regime, is studied. The mean-field finite-U slave-boson formalism is used to obtain the solution of the problem. We investigate the many body molecular Kondo state and its interplay with the inter-dot antiferromagnetic correlation as a function of the param
Brazilian Journal of Physics. Publicado em: 2006-09
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6. Conductance of three-dimensional cross junctions in the quantum ballistic regime
The influence of dimensionality on the conductance of semiconductor cross junctions is investigated in the effective mass approximation and quantum ballistic regime. Our calculations exhibit some similar features for both two- and three-dimensional models, namely the conductance peaks before the fundamental eigenenergy of the quantum wire that represents the
Brazilian Journal of Physics. Publicado em: 2006-06
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7. Electronic transport through a quantum wire with a side-coupled quantum dot
We describe the Kondo resonance in quantum dots employing the atomic model. We calculate approximate Green's functions of the impurity Anderson model employing the exact solution of the system with a conduction band with zero width, and we use the completeness condition to choose the position of that band. At low temperatures, there are two solutions close t
Brazilian Journal of Physics. Publicado em: 2006-06
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8. 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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9. Hydrogenated Ge nanocrystals: band gap evolution with increasing size
The electronic band structure of various Ge quantum wires of different sizes, with hydrogenated surfaces, is studied using a nearest-neighbor empirical tight-binding Hamiltonian by means of a sp³s* atomic orbitals basis set. We suppose that the nanostructures have the same lattice structure and the same interatomic distance as in bulk Ge and that all the da
Brazilian Journal of Physics. Publicado em: 2006-06
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10. Laser de faces clivadas com regiões ativas nanoestruturadas bombeados por injeção eletronica / Cleaved face laser with nanostructured active region pumped by electronic injection
This masters dissertation presents the theoretical studies on the calculation of optical gain in nanostructures based on the InGaAs/InGaAsP/InP system. From the time dependent perturbation theory, where perturbation is the interaction of an electromagnetic wave with matter, and the Kanes theory for semiconductors band structure, relating the transition m
Publicado em: 2006
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11. Exciton confinement in InGaN/GaN cylindrical quantum wires
We investigate the confined exciton properties in InGaN/GaN cylindrical quantum wires. We have solved numerically Schrödinger-like equations in the effective mass approximation and have found the energy levels and wavefunctions for confined electrons and holes, using these results to calculate variationally the confined exciton energy. A comparison was made
Brazilian Journal of Physics. Publicado em: 2004-06
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12. Study of the RPA pair-correlation function in GaAs-AlGaAs parabolic quantum well wires
The ground state intrasubband pair-correlation function for a quasi-one-dimensional electron gas confined in a GaAs-Al xGa1-xAs parabolic quantum well wire within the Random-Phase Approximation (RPA) is calculated. We have considered two wires with subband energies separation homega = 2:0 meV and homega = 2:5 meV. The dependence of the pair-correlation funct
Brazilian Journal of Physics. Publicado em: 2004-06