Effective Hamiltonians
Mostrando 1-5 de 5 artigos, teses e dissertações.
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1. Estudo das técnicas de obtenção de Hamiltonianos efetivos em Óptica Quântica
In the Quantum Optics area, the construction of effective hamiltonian is a matter of great importance, since from them we can generate and manipulate quantum states and logical operations. In this work we discuss 3 approximate methods for obtaining such effective hamiltonians: i) adiabatic elimination, ii) method of effective dynamics for oscillating hamilto
Publicado em: 2009
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2. Análise geométrica e dinâmica de modelos de gravidade generalizada / Geometrical and Dynamical Analysis of Generalized Gravity Models
This work aims the investigation of some dynamical aspects of generalized gravity models, namely scalar-tensor and f(R) models. These models intend to solve in a more natural way the problem of the existence of the dark energy, which is supposedly the component of the Universe that causes its accelerated expansion. In a null spatial curvature Friedmann-Lema�
Publicado em: 2008
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3. O efeito Casimir dinâmico e decoerência
In this thesis we first demonstrate that the inevitable action of the environment can be substantially weakened when considering appropriate nonstationary quantum systems. Beyond protecting quantum states against decoherence, an oscillating frequency can be engineered to make the system-reservoir coupling almost negligible. Differently from the program for e
Publicado em: 2008
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4. Engenharia de interações fônon-fóton-matéria mediadas por um campo clássico.
In this work we consider the problem of a three-level trapped ion inside a high- Q cavity. We study the process of phonon-foton-matter interaction mediated by a classical field. We are particularly interested in the engineering process of two excitation changes, phonons and/or photons, which result in squeezing of the cavity mode and/or the vibrational field
Publicado em: 2004
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5. First-principles calculations of the effective mass parameters of Al xGa1-xN and Zn xCd1-xTe alloys
First-principles calculations of electronic band structures of the ordered cubic alloys Al xGa1-xN and Cd xZn1-xTe are carried out. The band structures are used to provide e ective masses and Luttinger parameters which are useful in the parametrization of theories based on e ective hamiltonians.
Brazilian Journal of Physics. Publicado em: 2002-06