Programa de Pós-graduação em Física

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Navegando Programa de Pós-graduação em Física por Por Orientador "Baseia, Basilio"

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    Troca de Emaranhamento e Teletransporte Controlado no contexto de rotações de Faraday fotônicas
    (Universidade Federal de Goiás, 2011-03-04) Bastos, Wellison Peixoto; Cardoso, Wesley Bueno; Baseia, Basilio; http://lattes.cnpq.br/5804506385505435; Baseia, Basilio; Cardoso, Wesley Bueno; Mizrahi, Salomon Sylvain; Fonseca, Tertius Lima da
    Taking advantage of the Faraday rotations that occur in a photonic cristal placed in an optical cavity with low quality factor, we proposed two schemes to obtain the swapping of entanglement of atomic states, useful in quantum communication and quantum computation. They employ three-level atoms in a -configuration, a linearly polarized photon source, a single detector, and a quarter wave plate. Three (four) cavities are used in the first (second) scheme. An additional scheme was also proposed to obtain controlled teleportation of superposition states, partial controlled teleportation of entangled states and controlled teleportation of entanglement. In all schemes we have included the imperfections that affect the system, such as transmission and coupling of photons in optical components, the fraction of photons with a desired polarization, the quantum efficiency of single photon detection, the effective solid angle where the photon are collected, and the rate of emitted photons by the source. Under these realistic conditions we estimate the success probability of each proccess, including the time spent for its realization.
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    Superposição assimétrica de estados coerentes circulares
    (Universidade Federal de Goiás, 2002) Maia, Luciano Paulo de Araújo; Baseia, Basilio; http://lattes.cnpq.br/5804506385505435
    In this paper we present a new quantum state of light, obtained from an asymmetric superposition of coherent states in circular stationary mode. The generation of this state was proposed and the experimental apparatus required is presented. General expressions describing various properties (statistical distribution, variances, atomic inversion, etc..) Were obtained for arbitrary generations. We observed how they behave their properties by varying the phase between the components of superpo- sition states. We show that the statistical properties do not fully characterize the resulting state, showing different states with the same statistics. Alternative ways to distinguish these states were considered. Based on quantum interference in phase space, we show how we can generate an approximation of the number state N2 thru a process called "quantum sculpture,"and check the influence of the stage in this process. Finally, we measured the classicalidade not analyze this state and its representation in phase space.
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    Estudo e geração de estados não clássicos em nanocircuitos: propriedades e aplicações
    (Universidade Federal de Goiás, 2012) Valverde, Clodoaldo; Avelar, Ardiley Torres; http://lattes.cnpq.br/5732286631137637; Baseia, Basilio; http://lattes.cnpq.br/5804506385505435
    In this work we used an arrangement consisting of Cooper pairs (Cooper Pair Box, CPB) interacting with a nanomechanical Resonator (NR) for various studies: to produce controlable holes in the statistical distribution of excitations of the NR, for resonant and non-resonant cases; to study the evolution of the entropy and the inversion of excitations, including losses in the CPB; and to study the evolution of the Wigner function under the infuence of a reservoir. We have obtained the exact solution of the master equation describing the non-degenerate parametric amplifier interacting with a generalized model of linear phase sensitive reservoir, having the form of the equation equivalent to that of the Fokker-Planck propagator for the Wigner function. We have calculated the Wigner function describing the temporal evolution of a state initially in a superposition of two coherent states, a kind of "Schr?odinger cat", and finally, we have also studied the temporal evolution of the negativity of this function, one of the indicators of nonclassicality of vibrational states of the NR.