Browsing by Author "FERREIRA, MAURO"
Now showing items 1-20 of 37
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Amplitude coda of classical waves in disordered media
FERREIRA, MAURO (2002)The propagation of classical waves in the presence of a disordered medium is studied. We consider wave pulses containing a broad range of frequencies in terms of the configurationally averaged Green function of the system. ... -
Carbon nanotube: a low-loss spin-current waveguide
FERREIRA, MAURO (2010)We demonstrate with a quantum-mechanical approach that carbon nanotubes are excellent spin-current waveguides and are able to carry information stored in a precessing magnetic moment for long distances with very little ... -
A computationally efficient method for calculating the maximum conductance of disordered nanowire networks
FERREIRA, MAURO (2010)Random networks of carbon nanotubes and metallic nanowires have shown to be very useful in the production of transparent, conducting films. The electronic transport on the film depends considerably on the network properties, ... -
Contact-induced spin polarization in carbon nanotubes
FERREIRA, MAURO (2004)Motivated by the possibility of combining spintronics with molecular structures, we investigate the conditions for the appearance of spin polarization in low-dimensional tubular systems by contacting them to a magnetic ... -
Dynamics of classical wave scattering by small obstacles
FERREIRA, MAURO (American Physical Society, 2001)A causality problem in the time-dependent scattering of classical waves from point scatterers is pointed out and analyzed. Based on an alternative model, the leading pole approximation of the exact scattering matrix of ... -
"Effective Electrode Length Enhances Electrical Activation of Nanowire Networks: Experiment and Simulation"
FERREIRA, MAURO; BOLAND, JOHN; BELLEW, ALLEN; Fairfield, J.A.; McCarthy, Eoin K.; Ritter, Carlos (2014)Networks comprised of randomly oriented overlapping nanowires offer the possibility of simple fabrication on a variety of substrates, in contrast with the precise placement required for devices with single or aligned ... -
Electronic Contribution to the energetics of helically-wrapped nanotubes
FERREIRA, MAURO (2006)Motivated by evidence of helical wrapping of polymeric molecules around nanotubes, we calculate the electronic contribution to the energetics of linear charge distributions around a nanoscale cylindrical structure. This ... -
Electronic properties of nanotube-based sensors: an inverse modeling approach
FERREIRA, MAURO (2008)Nanotube-based sensors depend on significant conductivity changes induced by doping. Predictions of which impurity/nanotube combination provides efficient sensor characteristics are usually made on a case-by-case basis, ... -
Electronic structure of graphene beyond the linear dispersion regime
POWER, STEPHEN; FERREIRA, MAURO (2011)Among the many interesting features displayed by graphene, one of the most attractive is the simplicity with which its electronic structure can be described. The study of its physical properties is significantly simplified ... -
Electronic transport on carbon nanotube networks: a multiscale computational approach
PEREIRA, LUIZ FELIPE CAVALCANTI; FERREIRA, MAURO (2011)Carbon nanotube networks are one of the candidate materials to function as malleable, transparent, conducting films, with the technologically promising application of being used as flexible electronic displays. Nanotubes ... -
Enhanced magnetoresistance effect in layered systems
FERREIRA, MAURO (1999)Magnetoresistance ratios several orders of magnitude higher than those of conventional multilayers may be obtained with much smaller saturation fields in magnetic layers separated by a periodically modulated structure. ... -
Exchange coupling between iron layers separated by bcc. copper
FERREIRA, MAURO (American Physical Society, 1997)The exchange coupling between Fe layers separated by bcc Cu is calculated for Fe/Cu/Fe (001) trilayers. It is shown that the coupling is basically regulated by three extrema of the bulk bcc Cu Fermi surface. The contributions ... -
Exponential behavior of the interlayer exchange coupling across nonmagnetic metallic superlattices
FERREIRA, MAURO (1998)It is shown that the coupling between magnetic layers separated by nonmagnetic metallic superlattices can decay exponentially as a function of the spacer thickness N, as opposed to the usual N-2 decay. This effect is due ... -
Geometric Constraints in the Growth of Nanotube Templated Polymer Monolayers
COLEMAN, JONATHAN; FERREIRA, MAURO (2004)We present a simple and general model that describes the ordered assembly of polymer strands on nanotube surfaces. Energetically favorable coiling angles are identified based on geometric constraints that limit the maximum ... -
Graphene-based spin-pumping transistor
FERREIRA, MAURO (2010)We demonstrate with a fully quantum-mechanical approach that graphene can function as gate-controllable transistors for pumped spin currents, i.e., a stream of angular momentum induced by the precession of adjacent mag ... -
Impurity invisibility in graphene: Symmetry guidelines for the design of efficient sensors
FERREIRA, MAURO (2016)Renowned for its sensitivity to detect the presence of numerous substances, graphene is an excellent chemical sensor. Unfortunately, which general features a dopant must have in order to enter the list of substances ... -
Inadequacy of the asymptotic approximation for the interlayer coupling in Fe/Ag/Fe and Fe/Au/Fe (001) trilayers
FERREIRA, MAURO (American Physical Society, 1999)We discuss the basic assumptions underlying the stationary phase approximation to the interlayer exchange coupling between magnetic materials across nonmagnetic spacers. We show that, for temperatures and spacer thicknesses ... -
Indirect Exchange and RKKY Interactions in Magnetically-Doped Graphene
FERREIRA, MAURO (2013)Magnetically-doped graphene systems are potential candidates for application in future spintronic devices. A key step is to understand the pairwise interactions between magnetic impurities embedded in graphene that are ... -
Indirect exchange coupling between magnetic adatoms in carbon nanotubes
FERREIRA, MAURO (2005)The long-range character of the exchange coupling between localized magnetic moments indirectly mediated by the conduction electrons of metallic hosts can play a significant role in determining the magnetic order of ... -
Local electronic properties of carbon nanotube heterojunctions
FERREIRA, MAURO (2000)Local electronic properties of metallic-semiconducting carbon nanotube heterostructures are investigated by studying the behavior of the one-electron local density of states ~LDOS! along the tubes. We determine how these ...