Quantum Gates
Mostrando 1-11 de 11 artigos, teses e dissertações.
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1. Um estudo sobre computação quântica topológica : novas portas para o modelo de fibonacci / A Study on topological quantum computation : new gates to the fibonacci model
Neste trabalho, apresentamos um estudo sobre Computação Quântica Topológica, uma área de pesquisa inserida na computação quântica que busca resolver o problema da decoerência na construção do computador quântico de uma maneira inovadora. Essa computação envolve aspectos de áreas distintas relacionadas a mecânica quântica: teoria de grupos, r
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 29/02/2012
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2. Teoria de correção de erros quânticos durante operações lógicas e medidas de diagnóstico de duração finita / Quantum error-correction theory during logical gates and finitetime syndrome measurements
Neste trabalho, estudamos a teoria quântica de correção de erros, um dos principais métodos de prevenção de perda de informação num computador quântico. Este método, porém, normalmente é estudado considerando-se condições ideais em que a atuação das portas lógicas que constituem o algoritmo quântico não interfere com o tipo de erro que o s
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 17/02/2012
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3. Implementação de portas lógicas quânticas em condensados de Bose- Einstein acoplados
It is well established that the dynamics of two coupled Bose-Einstein condensates (BECs) can be described by using the two-mode Hamiltonian. This model takes into account the trap connement and the eects of collisions associated with each condensate. Other eects, as collision between atoms that belong to dierent BECs and detuning has been included in this ap
Publicado em: 2010
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4. Temporal resources for global quantum computing architectures
Using the methods for optimal simulation of quantum logic gates, we perform a quantitative estimation of the time resources involved in the execution of universal gate sets for the case of three representative models of quantum computation based on global control. The importance of such models stems from the solution to the problem of experimentally addressi
Brazilian Journal of Physics. Publicado em: 2008-12
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5. InformaÃÃo quÃntica e emaranhamento: uma abordagem usando Ãlgebra geomÃtrica
We studied the quantum entanglement as a quantum computation and quantum information tool. This research focused on the bipartite entanglement found between two qubits of a Heisenberg hamiltonian. The choice of this hamiltonian was motivated by the fact that it can be simulated by many distinct physical systems. Besides, the control of its parameters during
Publicado em: 2007
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6. Exchange energy in coupled quantum dots
In this work, the exchange energy J for a system of two laterally-coupled quantum dots, each one with an electron, is calculated analytically and in a detailed form, considering them as hydrogen-like atoms, under the Heitler-London approach. The atomic orbitals, associated to each quantum dot, are obtained from translation relations, as functions of the Fock
Brazilian Journal of Physics. Publicado em: 2006-09
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7. Quantum information processing through nuclear magnetic resonance
We discuss the applications of Nuclear Magnetic Resonance (NMR) to quantum information processing, focusing on the use of quadrupole nuclei for quantum computing. Various examples of experimental implementation of logic gates are given and compared to calculated NMR spectra and their respective density matrices. The technique of Quantum State Tomography for
Brazilian Journal of Physics. Publicado em: 2005-09
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8. Estudo de portas lógicas quânticas de dois qubits definidas em um subespaço livre de decoerência para um sistema de quatro qubits acoplado ao resto do universo por um agente degenerado / A study of two-qubit quantum logic gates defined in a decoherence free subspaces for a four-qubit system coupled to the rest of the universe via a degenerate agent
In this dissertation we studied theoretical aspects of some recent proposals of passive quantum information processing, that is, discarding error correction protocols. Falling back upon the creation of decoherence-free subspaces through a physical system of four spins coupled to the rest of the universe by a degenerate agent, we showed to be possible to buil
Publicado em: 2004
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9. Study of quantum decoherence and dissipation, during a two qubits temporal evolution controlled by unitary operations / Estudo da decoerência e da dissipação quântica durante a evolução temporal de dois qubits ditadas por operações unitárias controladas
Nessa dissertação, abordamos o problema de dois qubits interagindo com campos externos e entre si controladamente, de acordo com um Hamiltoniano considerado realista para implementação da porta lógica quântica XOR. Introduzimos acoplamentos entre as observáveis do sistema de dois qubits e um banho de osciladores harmônicos a fim de tratarmos o proble
Publicado em: 2004
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10. Espectroscopia de tunelamento em sistemas nanoscopicos de transporte balistico
In this work we discuss the ballistic transport properties of non-interacting electrons in confined nanoscopic system, where the sample boundaries and a controllable impurity repulsive, such as the one induced by scanning a Atomic Force Microscope tip or using split gates technique are the only source of electron sacttering. Two quantum scenary are studied:
Publicado em: 2003
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11. Estudo dos estados eletrônicos em sistemas quase-unidimensionais. / Study of electronic states in quasi-one-dimensional systems.
We have studied the electronic properties of two different quasi-one-dimensional systems solving self-consistently the Schrödinger and Poisson equation. The method we use to calculate the electronic levels is based on the solution of the time-dependent Schrödinger equation using the split-operator technique. In the first system we have studied, we present
Publicado em: 1997