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Modelos dinâmicos de magnetização aplicados em compósitos magnetoelétricos
(Universidade Federal de São Carlos, 2014-04-01)
In this thesis we study the magnetic properties of the multiferroic composite (1-x)Pb(Mg1/3Nb2/3)-xPbTiO3/CoFe2O4 (PMN-PT/CFO) sintered by hot forging. Magnetization as a function of magnetic field, magnetoelectric effect ...
Modelos de spins geometricamente frustrados: transição de fase e estruturas de platores
(Universidade Federal de São Carlos, 2013-04-08)
This thesis presents a study of the magnetization plateau and the phenomenon of geometrical frustration in spin systems applied to lattices with triangular structure, as well as the results achieved by applying the ...
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 ...
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 ...
Superposição de estados comprimidos de dois modos e aplicações em informação quântica
(Universidade Federal de São Carlos, 2019-03-07)
In this work, we present a new class of quantum states for applications in quantum
metrology and quantum information, the states here named as “Even EPR” and “Odd
EPR”. We present a review of the basic concepts of ...
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 ...
Magneto luminescência em diodos de tunelamento ressonante contendo pontos quânticos de InAs
(Universidade Federal de São Carlos, 2011-03-15)
In this work, we have studied the spin polarization of carriers in n-type resonant tunneling diodes (RTDs) of GaAs/AlGaAs which incorporates a single layer of InAs selfassembled quantum dots in the center of the GaAs quantum ...