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Efeitos de spin em diodos de tunelamento ressonante tipo-p
(Universidade Federal de São Carlos, 2012-03-27)
In this work, we have investigated the spin effects in p-i-p GaAs/AlAs resonant tunneling diodes under magnetic field parallel to the tunnel current. The spin-dependent tunneling of carriers was studied by analyzing the ...
Simulações de líquidos super-resfriados via dinâmica molecular
(Universidade Federal de São Carlos, 2012-10-15)
This work presents the study of two models of glass-forming liquids using molecular dynamics simulations. The first model aims to analyze the effects on glassy dynamics which allow the enhancement of the glass formability ...
Propriedades de transporte de spins polarizados em heteroestruturas semicondutoras
(Universidade Federal de São Carlos, 2009-06-25)
In this work we used the technique of scattering matrix to calculate the transmissivity of polarized spins in a semiconductor symmetrical double-barrier heterostruture. The dynamics of carriers is described by effective ...
Estrutura de platô na magnetização em modelos de spins frustrados
(Universidade Federal de São Carlos, 2012-10-26)
This thesis study the phase transition, forms classical and quantum models of spin frustration. The Heisenberg model of spin 1/2 with exchange anisotropy with competitive interactions between first (J1) and second (J2) ...
Estudo de primeiros princípios das propriedades eletrônicas de novos materiais derivados do grafeno : as nanofitas e nanofios
(Universidade Federal de São Carlos, 2012-09-05)
In this thesis, we study new materials derived from graphene, like nanowires and nanoribbons, with numerical calculations based on the density functional theory (DFT) and the non-equilibrium Green functions (NEGF). We will ...
Flux avalanches in patterned superconducting thin films: ac susceptibility, morphology and related studies
(Universidade Federal de São Carlos, 2013-04-12)
Avalanches are sudden dramatic phenomena that occur in nature. The technique of magneto-optical imaging (MOI) has allowed us to observe abrupt flux entrances in superconductors, the so-called ux avalanches, due to ...
Controle das propriedades estatísticas do campo e biestabilidade óptica em eletrodinâmica quântica de cavidades
(Universidade Federal de São Carlos, 2013-03-27)
We investigate in this thesis the control of absorptive optical bistability in a standing wave optical cavity filled with a collection of two and three-level noninteracting atoms weakly coupled to a single electromagnetic ...
Comunicação quântica baseada no teletransporte em variáveis contínuas
(Universidade Federal de São Carlos, 2014-12-12)
In this Thesis we study in details one of the most astonishing application of quantum mechanics which totally departs from our common sense: quantum teleportation in continuous variables. We present a review of the postulates ...
Magnetismo d0 em óxidos de In2O3 e (Sn1-xCex)O2
(Universidade Federal de São Carlos, 2019-05-02)
We investigated the structural, optical and magnetic properties of two nanoparticles oxide systems: In2O3, prepared by the high energy mechanical milling process, and (Sn1-xCex)O2 produced by the Pechini method, using ...
Eletrocerâmicas de BNBK dopadas com tântalo: processamento, fenomenologia e propriedades de armazenamento de energia
(Universidade Federal de São Carlos, 2019-03-29)
Global energy demand for high energy storage capability materials associated with the search for lead-free electroceramic materials with suitable properties for applications has become the major topic in functional materials ...