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[en] The termination of pinned spirals on a defect by means of local stimuli is studied. On a completely unexcitable defect, the elimination process is discussed and its corresponding mechanism is presented. Especially, the mechanism of unpinning spirals on a partially unexcitable defect, which has not been investigated so far, is explored. With fixed pacing frequency ω L, there exists a maximal radius R max above which the pinned spiral cannot be removed. It is found that the value of R max does not increase as ω L in a dynamical regime, forming a platform in the curves. Based on analyzing the dispersion relation on the spiral tip around the obstacle, the underlying mechanism is clarified. Also, it is found that when multiple spirals are pinned, the value of R max decreases on a partially unexcitable defect while the change is very slight on a completely unexcitable one. (letter)
[en] We report the plasmon dispersion characteristics of intrinsic and extrinsic armchair graphene nanoribbons of atomic width N = 5 using a pz-orbital tight binding model with third-nearest-neighbor (3nn) coupling. The hopping parameters are obtained by fitting the 3nn dispersions to those of an extended Hückel theory. The resultant massive Dirac fermion system has a band gap Eg ≈ 64 meV. The extrinsic plasmon dispersion relation is found to asymptotically approach a universal dispersion curve as the chemical potential μ increases, whereas the intrinsic plasmon dispersion relation is found to have both energy and momentum thresholds. We also report an analytical model for the extrinsic plasmon group velocity in the q → 0 limit.
[en] A simplified derivation of the dispersion relations connecting the phase and amplitude of the normal optical reflectivity of a vacuum-matter interface is presented. The non-Kramers-Kronig form of the expression for reflectivity in terms of phase is shown to be a consequence of the fact that amplitudes are determined only up to a multiplicative constant by the phase. The phase, however, is uniquely determined by the amplitude
[en] This report presents the atmospheric dispersion coefficients used in Tank Farms safety analysis. The basis equations for calculating radiological and toxicological exposures are also included. In this revision, the time averaging for toxicological consequence evaluations is clarified based on a review of DOE complex guidance and a review of tank farm chemicals.
[en] In this paper, we investigate the localized surface modes in a defective multilayer structure. We show that the defective multilayer structure can support two different kinds of localized modes, depending on the position and the thickness of the defect layer. In one kind, the modes are localized at the interface between the multilayer structure and a homogeneous medium (the so-called surface modes). While, in the other one, the modes are localized at the defect layer (defect-localized modes). We reveal that in the presence of the defect layer, the dispersion curve of the surface modes are pushed to the lower (upper) edge of the photonic band gap when the homogeneous medium is a left-handed (right-handed) material. Therefore, the existence regions of the surface modes are restricted due to the defect layer. Moreover, the effect of defect on the energy flow velocity of the surface modes is discussed.
[en] We experimentally study the strongly coupled three-level atom-cavity system at both cavity and coupling frequency detuning cases. Side peak splitting and anti-crossing-like phenomena are observed under different experimental conditions. Intracavity dispersion properties are used to explain qualitatively the complicated cavity resonance structures in the composite system of inhomogeneously broadened three-level atoms inside an optical ring cavity with relatively strong driving intensities.
[en] One elaborated a theory of dispersion surface polaritons, that was, the localized electromagnetic waves at the arbitrary oriented metallized boundaries of the optically single-axis crystals. The region of occurrence of polaritons was given by the following inequalities to be obeyed by εo and εe crystal permittivities and by θ inclination angle of the optical axis to the surface: -εetg2θ<εo < 0. One examined behavior peculiarities of the polariton parameters near the boundaries of the region of its occurrence,where wave fields were particularly sensitive to variations of θ and φ angles. It is shown that for the propagation plane (the sagittal plane) passing through the optical axis the polariton changes to a single-partial bulk wave obeying the boundary conditions. Respectively, for the similar orientations when the optical axis forms a shallow angle with the sagittal plane the examined wave branch describes deeply penetrating (quasi-solid) polaritons
[ru]Построена теория дисперсионных поверхностных поляритонов - локализованных электромагнитных волн - на произвольно ориентированных металлизированных границах оптически одноосных кристаллов. Область существования поляритонов задана следующими неравенствами, которым должны удовлетворять диэлектрические проницаемости кристалла εo, εe и угол наклона θ оптической оси к поверхности: -εe tg2 θ < εo < 0. Изучены особенности поведения параметров поляритона вблизи границ зоны его существования, где волновые поля особенно чувствительны к изменениям углов θ и φ. Показано, что для плоскости распространения (сагиттальной плоскости), проходящей через оптическую ось, поляритон превращается в однопарциальную объемную волну, удовлетворяющую граничным условиям. Соответственно, для близких ориентаций, когда оптическая ось составляет малый угол с саггитальной плоскостью, рассматриваемая волновая ветвь описывает глубоко проникающие (квазиобъемные) поляритоны
[en] The dispersion relations of the surface polariton in a semi-infinite wire medium with spatial dispersion are analysed. In comparison with the traditional spatial dispersive medium there only exists one branch instead of multibranch for the dispersion curve. The possibility of the experimentally observing the surface polaritons by attenuated total reflection is simulated numerically
[en] We present the compact group approach to the analysis of the long-wavelength dielectric and optical characteristics of substances which can be modeled as macroscopically homogeneous and isotropic systems of hard dielectric particles embedded into a dielectric matrix. After the basic of the method are outlined, we discuss the results obtained with it for the effective permittivity of such systems and the single-scattering intensity of light scattered by them.