57,920 research outputs found
Complete light absorption in graphene-metamaterial corrugated structures
We show that surface-plasmon polaritons excited in negative permittivity
metamaterials having shallow periodic surface corrugation profiles can be
explored to push the absorption of single and continuous sheets of graphene up
to 100%. In the relaxation regime, the position of the plasmonic resonances of
the hybrid system is determined by the plasma frequency of the metamaterial,
allowing the frequency range for enhanced absorption to be set without the need
of engineering graphene.Comment: 6 pages, 4 figures; published version: text revised and references
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Exchange coupling between magnetic layers across non-magnetic superlattices
The oscillation periods of the interlayer exchange coupling are investigated
when two magnetic layers are separated by a metallic superlattice of two
distinct non-magnetic materials. In spite of the conventional behaviour of the
coupling as a function of the spacer thickness, new periods arise when the
coupling is looked upon as a function of the number of cells of the
superlattice. The new periodicity results from the deformation of the
corresponding Fermi surface, which is explicitly related to a few controllable
parameters, allowing the oscillation periods to be tuned.Comment: 13 pages; 5 figures; To appear in J. Phys.: Cond. Matte
A novel framework for the use of workflow system in the integration of supply chain tiers
The global competition has imposed challenges to supply chain integration, mainly, during the process of obtain information to make demand management decisions. This paper proposes an integrated framework for data collection, analysis and results dissemination in the supply chain management (SCM), contributing to research and alternatives for \u201cThe Bullwhip Effect\u201d issue. In this sense, it is necessary to discuss the integration of supply chain management, Enterprise Resources Planning (ERP) functionality and others systems, to enlarge this scope to the total supply chain players. The ERP web-based tool and Workflow Systems (WS) can contribute to solve issues related to supply chain management. Starting from a detailed analysis of the research background regarding current SCM definitions and integration problems, Information Technology and Communication (ITC) development and WS in order to map and ensure flow fluency; the paper proposes a model to increase the overall integrations and an application in a case study for supporting the decisions that are aligned with the company\u2019s strategic objectives. This paper is divided in: research background; proposed model of the SC integration; case study, conclusions and future research
First- and second-order phase transitions in Ising models on small world networks, simulations and comparison with an effective field theory
We perform simulations of random Ising models defined over small-world
networks and we check the validity and the level of approximation of a recently
proposed effective field theory. Simulations confirm a rich scenario with the
presence of multicritical points with first- or second-order phase transitions.
In particular, for second-order phase transitions, independent of the dimension
d_0 of the underlying lattice, the exact predictions of the theory in the
paramagnetic regions, such as the location of critical surfaces and correlation
functions, are verified. Quite interestingly, we verify that the
Edwards-Anderson model with d_0=2 is not thermodynamically stable under graph
noise.Comment: 12 pages, 12 figures, 1 tabl
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