Showing papers by "Áurea R. Vasconcellos published in 2012"
TL;DR: The case of a peculiar complex behavior in open boson systems sufficiently away from equilibrium, having relevance in the functioning of information-processing biological and condensed matter systems is considered.
Abstract: We consider the case of a peculiar complex behavior in open boson systems sufficiently away from equilibrium, having relevance in the functioning of information-processing biological and condensed matter systems. This is the so-called Frohlich–Bose–Einstein condensation, a self-organizing-synergetic dissipative structure, a phenomenon apparently working in biological processes and present in several cases of systems of boson-like quasi-particles in condensed inorganic matter. Emphasis is centered on the quantum-mechanical-statistical irreversible thermodynamics of these open systems, and the informational characteristics of the phenomena.
17 citations
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TL;DR: In this article, a response function theory and scattering theory applicable to the study of physical properties of systems driven arbitrarily away from equilibrium, specialized for dealing with ultrafast processes and in conditions of space resolution (including nanometric scale), are presented.
Abstract: A Response Function Theory and Scattering Theory applicable to the study of physical properties of systems driven arbitrarily away from equilibrium, specialized for dealing with ultrafast processes and in conditions of space resolution (including nanometric scale), are presented. The derivation is done in the framework of a Gibbs-style Nonequilibrium Statistical Ensemble Formalism. It is shown the connection of the observable properties with time and space-dependent correlation functions out of equilibrium. A generalized fluctuation-dissipation theorem, which relates these correlation functions with generalized susceptibilities is derived. It is also presented the method, useful for calculations, of nonequilibrium-thermodynamic Green functions. A couple of illustration with application of the formalism, consisting of the study of optical responses in ultrafast laser spectroscopy and Raman Scattering of electrons in III-N semiconductors (of "blue diodes") driven away from equilibrium by action of electric fields of moderate to high intensities, are described.
2 citations
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TL;DR: In this article, a generalized hydrodynamics of phonons in semiconductors is presented, which involves the descriptions of the motion of the quasi-particle density and of the energy density.
Abstract: A generalized Hydrodynamics, referred to as Mesoscopic Hydro-Thermodynamics, of phonons in semiconductors is presented. It involves the descriptions of the motion of the quasi-particle density and of the energy density. The hydrodynamic equations, which couple both types of movement via thermo-elastic processes, are derived starting with a generalized Peierls-Boltzmann kinetic equation obtained in the framework of a Non-Equilibrium Statistical Ensemble Formalism, providing such a Mesoscopic Hydro-Thermodynamics. The case of a contraction in first order relevant variables is worked out in detail. The associated Maxwell times are derived and discussed. The densities of quasi-particles and of energy are found to satisfy coupled Maxwell-Cattaneo-like hyperbolic equations. The analysis of thermo-elastic effects is done and applied to investigate thermal distortion in silicon mirrors under incidence of high intensity X-ray pulses in free electron laser (FEL) facilities. The derivation of a generalized Guyer-Krumhansl equation governing the flux of heat and the associated conductivity coefficient is also presented.