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"Probabilidades negativas" e tomografia de Qubits
(Universidade Federal de São Carlos, 2007-03-28)
In this dissertation we approached the tomography of discrete systems, understood as the representation
and the reconstruction of states. For the tomography we used distribution functions
of symmetrical pseudo-probabilities. ...
Propriedades de transporte eletrônico em filmes de diamante crescidos por deposição de vapores químicos
(Universidade Federal de São Carlos, 2007-02-27)
In this work it was investigated some fundamental properties of undoped and Borondoped
(p-type) synthetic diamond films. It was investigated the influence of the cleaning
process on the surface s quality in order to ...
Obtenção, propriedades e fenomenologia de materiais ferroelétricos com estrutura tungstênio bronze
(Universidade Federal de São Carlos, 2007-02-23)
The processing of lead metaniobate (PN) ferroelectric ceramics was optimized, therefore, in
this work, the main details to obtain PN ceramics with density higher than 96 % of the ideal density
are presented and ...
Estudo por espalhamento Raman de efeitos anarmônicos e transição de fase do PbTiO3 : Sm3+ induzidos por pressão hidrostática e variação de temperatura
(Universidade Federal de São Carlos, 2007-10-05)
In this work it was investigated, by using Raman spectroscopy, the effect of
the substitucional disorder on the vibrational properties of the ferroelectric
ceramics PbTiO3 doped with Samarium, at different temperatures ...
Caracterização ótica de poços quânticos de GaMnAs
(Universidade Federal de São Carlos, 2007-09-12)
In this work, we have studied GaAs/AlAs/Ga1-xMnxAs quantum wells (QWs) with low Mn concentration ( 0 < x < 0,2%). The samples were grown by Molecular Beam Epitaxy (MBE) in high temperature (450 C). The growth conditions ...
Transição de fase quântica e modelos de spins frustrados
(Universidade Federal de São Carlos, 2007-03-15)
In this thesis, we will study the quantum phase transition of frustrated quantum spin
models: (i) van Hemmen model ( S = 1) with transverse and anisotropic biaxial field (ii)
Heisenberg model (S = 1/2 ) with competitive ...
Espectroscopia mecânica em tântalo
(Universidade Federal de São Carlos, 2007-03-15)
The mechanical spectroscopy technique applied to diffusion studies in body-centered cubic (BCC) metals, such as tantalum. Transition metals, as the tantalum, that has a crystalline structure (BCC), can dissolve large amounts ...
Monovacâncias em grafite por cálculos de primeiros princípios
(Universidade Federal de São Carlos, 2007-02-26)
Caracterização elétrica, dielétrica e anelástica de transições de fase em cerâmicas de Pb (Fe1/2Nb1/2)O3
(Universidade Federal de São Carlos, 2007-09-20)
El Niobato de plomo y hierro Pb(Fe1/2Nb1/2)O3 es un material multiferroico: es ferroeléctrico a temperaturas inferiores a 383K y antiferromagnético a temperaturas inferiores a 143K, presentando propiedades magnetoelétricas ...
Fases geométricas e invariantes dinâmicos em mecânica quântica
(Universidade Federal de São Carlos, 2007-05-16)
The increasing interest to understand the geometric phases (mainly due to the possi-
bility to achieve geometric quantum computation robust against some kind of errors) and
the search for new techniques to solve time-dependent ...