106,813 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
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
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
Relaxation-to-creep transition of domain-wall motion in two- dimensional random-field Ising model with ac driving field
With Monte Carlo simulations, we investigate the relaxation dynamics with a
domain wall for magnetic systems at the critical temperature. The dynamic
scaling behavior is carefully analyzed, and a dynamic roughening process is
observed. For comparison, similar analysis is applied to the relaxation
dynamics with a free or disordered surfaceComment: 5 pages, 5 figure
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