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Autor Maciá Barber, Enrique Alfonso |
Documentos disponibles escritos por este autor (55)
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In this work we present a prospective study on the potential capabilities of optical devices based on Fibonacci dielectric multilayers. We perform a detailed analytical comparison of the linear optical response of periodic versus quasiperiodic m[...]texto impreso
Domínguez-Adame Acosta, Francisco ; Maciá Barber, Enrique Alfonso ; Méndez Martín, Bianchi ; Roy, C.L. ; Khan, A. | IOP publishing ltd | 1995-06We report the theoretical electronic structure of Fibonacci superlattices of narrow-gap III-V semiconductors. The electron dynamics is accurately described within the envelope-function approximation in a two-band model. Quasiperiodicity is intro[...]texto impreso
Domínguez-Adame Acosta, Francisco ; Maciá Barber, Enrique Alfonso | American Physical Society | 1996-05-15We study motion and capture of excitons in self-similar linear systems in which interstitial traps are arranged according to an aperiodic sequence, focusing our attention on Fibonacci and Thue-Morse systems as canonical examples. The decay of th[...]texto impreso
We study the phonon dynamics of Fibonacci heterostructures where two kinds of order (namely, periodic and quasiperiodic) coexist in the same sample at different length scales. We derive analytical expressions describing the dispersion relation o[...]texto impreso
Domínguez-Adame Acosta, Francisco ; Maciá Barber, Enrique Alfonso ; Sánchez, Angel | American Physical Society | 1995-01-01Incoherent exciton dynamics in one-dimensional perfect lattices with traps at sites arranged according to aperiodic deterministic sequences is studied. We focus our attention on Thue-Morse and Fibonacci systems as canonical examples of self-simi[...]texto impreso
Roche, S. ; Bicout, D. ; Maciá Barber, Enrique Alfonso ; Kats, E. | American Physical Society | 2003-10-28We address the relation between long-range correlations and charge transfer efficiency in aperiodic artificial or genomic DNA sequences. Coherent charge transfer through the highest occupied molecular orbital states of the guanine nucleotide is [...]texto impreso
We present a theoretical analysis of quasicrystals (QCs) as potential thermoelectric materials. We consider a self-similar density of states model and extend the framework introduced in [G. D. Mahan and J. O. Sofo, Proc. Natl. Acad. Sci. U.S.A. [...]texto impreso
A model for the electronic structure of icosahedral quasicrystals is proposed on the basis of a number of pertinent experimental results. From this model we obtain a closed analytical expression for the electrical conductivity accurately describ[...]texto impreso
Maciá Barber, Enrique Alfonso ; Takeuchi, Tsunehiro ; Otagiri, Toshio | American Physical Society | 2005-11The electronic structure of a quasicrystalline approximant sample is analyzed by means of a combined study of different experimental transport curves within a phenomenological approach. The main features of the obtained spectral conductivity are[...]texto impreso
Domínguez-Adame Acosta, Francisco ; Méndez Martín, Bianchi ; Maciá Barber, Enrique Alfonso ; González, M. A. | Taylor & Francis Ltd | 1991-12-10It is shown that nonlocal separable potentials may be used to study bound states of particles in multicentre potentials. The binding energy is obtained in a closed form. The cases of H_2+ ion and polymer chains are discussed in detail and result[...]texto impreso
Domínguez-Adame Acosta, Francisco ; Maciá Barber, Enrique Alfonso ; Sánchez, Angel | American Physical Society | 1994-09-01Optical absorption in a random one-dimensional lattice in the presence of paired correlated disorder is studied. The absorption line shape is evaluated by solving the microscopic equations of motion of the Frenkel-exciton problem in the lattice.[...]texto impreso
In this work we analyze the potential role of quasicrystals and related alloys in thermoelectric material research. Relatively large figure of merit values are expected for those samples exhibiting two properly located narrow features in the den[...]texto impreso
The presence of synchronized, collective twist motions of the Watson-Crick base pairs in DNA duplexes (helicoidal standing waves) can efficiently enhance the pi-pi orbital overlapping between nonconsecutive base pairs via a long-range, phonon-co[...]texto impreso
We report on the possibility of modulating the transport properties of critical normal modes in Fibonacci quasicrystals by using the mass ratio as a tuning parameter. The relationship between the spatial structure and the transport properties of[...]texto impreso
Maciá Barber, Enrique Alfonso ; Domínguez-Adame Acosta, Francisco | American Physical Society | 1996-04-15We report on a new class of critical states in the energy spectrum of general Fibonacci systems. By introducing a transfer matrix renormalization technique, we prove that the charge distribution of these states spreads over the whole system, sho[...]texto impreso
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In this work we introduce a similarity transformation acting on transfer matrices describing the propagation of elementary excitations through either periodic or Fibonacci lattices. The proposed transformation can act at two different scale leng[...]texto impreso
A spectral classification of general one-dimensional binary aperiodic crystals (BACs) based on both their diffraction patterns and energy spectrum measures is introduced along with a systematic comparison of the zeroth-order energy spectrum main[...]texto impreso
Sáchez, A. ; Maciá Barber, Enrique Alfonso ; Domínguez-Adame Acosta, Francisco | American Physical Society | 1994-01-01We consider the electron dynamics and transport properties of one-dimensional continuous models with random, short-range correlated impurities. We develop a generalized Poincare map formalism to cast the Schrodinger equation for any potential in[...]texto impreso
The validity of the Wiedemann-Franz law (WFL) for icosahedral quasicrystals belonging to the families AlCu(Fe,Ru) and AlPd(Mn,Re) is discussed. We exploit some characteristic features in the electronic structure in order to obtain closed analyti[...]texto impreso
In this work we present a theoretical study on the possible use of quasicrystals as potential thermoelectric materials. By considering a suitable model for the spectral conductivity we show that high values of the thermoelectric figure of merit,[...]texto impreso
In this work we consider the range of validity of the Wiedemann-Franz law (WFL) in quasicrystals, approximant phases, and giant unit-cell complex metallic alloys. In the limit of very low temperatures the WFL is satisfied, as expected, but as th[...]texto impreso
We consider a general Fibonacci quasicrystal (FQC) in which both the masses and the elastic constants are aperiodically arranged. Making use of a suitable decimation scheme, inspired by real-space renormalization-group concepts, we obtain closed[...]texto impreso
Aperiodic photonic crystals can open up novel routes for more efficient photon management due to increased degrees of freedom in their design along with the unique properties brought about by the long-range aperiodic order as compared to their p[...]texto impreso
In this work we present a theoretical study on the composition dependence of the thermoelectric figure of merit (ZT) of icosahedral AlPdRe quasicrystals. From our study we conclude that band-structure effects play a significant role in determini[...]