155 research outputs found

    Interface modes in nanostructured metal-dielectric metamaterials

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    We study surface modes at an interface separating two different layered metal-dielectric metamaterials. We demonstrate that, in a sharp contrast to the effective-medium approach predicting a single interface mode with the surface-plasmon dispersion, the transfer-matrix method reveals the existence of three types of localized interface modes, including a backward interface mode. These results confirm that metal-dielectric nanostructured metamaterials can demonstrate strong optical nonlocality due to the excitation of surface plasmon polaritons.The authors acknowledge the support from a mega-grant of the Ministry of Education and Science of Russian Federation (Russia), EPSRC (UK), Dynasty Foundation, and Australian Research Council through the Discovery and Center of Excellence Programs (Australia)

    Engineered Optical Nonlocality in Nanostructured Metamaterials

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    We analyze dispersion properties of metal-dielectric nanostructured metamaterials. We demonstrate that, in a sharp contrast to the results for the corresponding effective medium, the structure demonstrates strong optical nonlocality due to excitation of surface plasmon polaritons that can be engineered by changing a ratio between the thicknesses of metal and dielectric layers. In particular, this nonlocality allows the existence of an additional extraordinary wave that manifests itself in the splitting of the TM-polarized beam scattered at an air-metamaterial interface

    High-level system-on-chip simulator

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    A high-level simulation is a significant part of the multicore system-on-chip (SoC) software development process. It allows executing programs and performing functional debugging on the high-level model of the SoC without going into details of SoC heterogeneous cores: a specific command set, a processes interaction, a communication system specifics etc. The high-level simulation is also a necessary part of the SW/HW co-design tool flows. This paper presents the developed high-level SoC simulator. This simulator allows executing coarse-grain programs in the configurable SoC-style distributed environment with heterogeneous processing elements and an interconnection. A parallel data-processing workload (SoC program) is been defining as a scheme of interacting processes with a C/C++ implementation and specific characteristics. Various simulation statistics allows investigating characteristics of a developed program (maximal parallelism levels, computation space requirements, amounts of interaction data), abilities of SoC architecture to perform such workload (processing elements and communication system occupation, buffers size distribution, queues etc.) and characteristics of program execution (processing time, latencies, constraints)

    Scattering Suppression from Arbitrary Objects in Spatially-Dispersive Layered Metamaterials

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    Concealing objects by making them invisible to an external electromagnetic probe is coined by the term cloaking. Cloaking devices, having numerous potential applications, are still face challenges in realization, especially in the visible spectral range. In particular, inherent losses and extreme parameters of metamaterials required for the cloak implementation are the limiting factors. Here, we numerically demonstrate nearly perfect suppression of scattering from arbitrary shaped objects in spatially dispersive metamaterial acting as an alignment-free concealing cover. We consider a realization of a metamaterial as a metal-dielectric multilayer and demonstrate suppression of scattering from an arbitrary object in forward and backward directions with perfectly preserved wavefronts and less than 10% absolute intensity change, despite spatial dispersion effects present in the composite metamaterial. Beyond the usual scattering suppression applications, the proposed configuration may serve as a simple realisation of scattering-free detectors and sensors

    Nonlocal effective parameters of multilayered metal-dielectric metamaterials

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    We consider multilayered metal-dielectric metamaterials composed of alternating nanolayers of two types and calculate the components of their effective dielectric permittivity tensors as functions of both frequency and wave vector. We demonstrate that such structures can be described as strongly nonlocal uniaxial effective media, and we analyze how the nonlocal permittivity tensor components are related to other manifestations of strong spatial dispersion in such structures, and how the resonance of permittivity depends on the propagation direction

    Nonlocal effective medium model for multilayered metal-dielectric metamaterials

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    We study layered metal-dielectric structures, which can be considered as a simple example of nanostructured metamaterials. We analyze the dispersion properties of such structures and demonstrate that they show strong optical nonlocality due to excitatio

    Ensuring the rational temperature conditions for concrete hardening

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    One of the important aspects of the production technology of monolithic reinforced concrete is to ensure the rational temperature hardening of concrete that can provide high-quality concrete with a minimum duration of heat treatment and minimize energy costs. The article contains ways to solve the problem of ensuring a rational temperature setting of hardening. The task requires the development of a general method for calculating the temperature field of concrete in a hardening reinforced concrete structure. The proposed method of calculating considers a mathematical model of the temperature field in a hardening concrete structure of any shape with different conditions on the heat exchange surfaces and can be applied in various ways of heat treatment of concrete. For solving the equations of thermal conductivity and kinetics of heat release of concrete, the initial and boundary conditions must be specified. Moreover, the influence of reinforcing and simulation of heat distribution in the frozen basis is studied

    Retrieval of Effective Parameters of Subwavelength Periodic Photonic Structures

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    We revisit the standard Nicolson–Ross–Weir method of effective permittivity and permeability restoration of photonic structures for the case of subwavelength metal-dielectric multilayers. We show that the direct application of the standard method yields a false zero-epsilon point and an associated spurious permeability resonance. We show how this artifact can be worked around by the use of the cycle shift operator to the periodic multilayer in question
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