107,307 research outputs found
Effect of the attachment of ferromagnetic contacts on the conductivity and giant magnetoresistance of graphene nanoribbons
Carbon-based nanostructures and graphene, in particular, evoke a lot of
interest as new promising materials for nanoelectronics and spintronics. One of
the most important issue in this context is the impact of external electrodes
on electronic properties of graphene nanoribbons (GNR). The present theoretical
method is based on the tight-binding model and a modified recursive procedure
for Green's functions. The results show that within the ballistic transport
regime, the so called end-contacted geometry (of minimal GNR/electrode
interface area), is usually more advantageous for practical applications than
its side-contacted counterpart (with a larger coverage area), as far as the
electrical conductivity is concerned. As regards the giant magnetoresistance
coefficient, however, the situation is exactly opposite, since spin- splitting
effects are more pronounced in the lower conductive side-contacted setups.Comment: 8 pages, 4 figure
Density-dependent deformed relativistic Hartree-Bogoliubov theory in continuum
The deformed relativistic Hartree-Bogoliubov theory in continuum with the
density-dependent meson-nucleon couplings is developed. The formulism is
briefly presented with the emphasis on handling the density-dependent
couplings, meson fields, and potentials in axially deformed system with partial
wave method. Taking the neutron-rich nucleus Mg as an example, the newly
developed code is verified by the spherical relativistic continuum
Hartree-Bogoliubov calculations, where only the spherical components of the
densities are considered. When the deformation is included self-consistently,
it is shown that the spherical components of density-dependent coupling
strengths are dominant, while the contributions from low-order deformed
components are not negligible.Comment: 5 pages, 3 figures, and 1 tabl
Chosen-Plaintext Cryptanalysis of a Clipped-Neural-Network-Based Chaotic Cipher
In ISNN'04, a novel symmetric cipher was proposed, by combining a chaotic
signal and a clipped neural network (CNN) for encryption. The present paper
analyzes the security of this chaotic cipher against chosen-plaintext attacks,
and points out that this cipher can be broken by a chosen-plaintext attack.
Experimental analyses are given to support the feasibility of the proposed
attack.Comment: LNCS style, 7 pages, 1 figure (6 sub-figures
Self-organized Boolean game on networks
A model of Boolean game with only one free parameter that denotes the
strength of herd behavior is proposed where each agent acts according to the
information obtained from his neighbors in network and those in the minority
are rewarded. The simulation results indicate that the dynamic of system is
sensitive to network topology, where the network of larger degree variance,
i.e. the system of greater information heterogeneity, leads to less system
profit. The system can self-organize to a stable state and perform better than
random choice game, although only the local information is available to the
agents. In addition, in heterogeneity networks, the agents with more
information gain more than those with less information for a wide extent of
herd strength .Comment: 5 pages, 5 eps figure
Neutron halo in deformed nuclei from a relativistic Hartree-Bogoliubov model in a Woods-Saxon basis
Halo phenomenon in deformed nuclei is studied by using a fully
self-consistent deformed relativistic Hartree-Bogoliubov model in a spherical
Woods-Saxon basis with the proper asymptotic behavior at large distance from
the nuclear center. Taking a deformed neutron-rich and weakly bound nucleus
Mg as an example and by examining contributions of the halo, deformation
effects, and large spatial extensions, we show a decoupling of the halo
orbitals from the deformation of the core.Comment: 6 pages, 2 figures, to appear in the proceedings of the International
Nuclear Physics Conference (INPC 2010), July 4-9 2010, Vancouve
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