scholarly journals Локализация возбуждений в слоистой структуре с границами раздела, характеризующимися нелинейным откликом

2019 ◽  
Vol 61 (3) ◽  
pp. 571
Author(s):  
С.Е. Савотченко
Keyword(s):  
Surface Waves ◽  
Nonlinear Response ◽  
Layer Structure ◽  
Localized States ◽  
Frequency Range ◽  
One Dimensional ◽  
Localized State ◽  
Symmetric Structure ◽  
The Media ◽  
Field Localization

AbstractThe features of localization of excitations in a three-layer structure in which linear media are separated by boundaries with their own nonlinear response have been examined. It is shown that in the three-layer structure under consideration, localized states of two types can exist that differ in the distribution of the field in the inner layer, as well as in the frequency range of existence. Dispersion relations have been obtained that determine the energy dependence on system parameters in each case. The damping factors of surface waves are obtained in an explicit form. The conditions of the field localization are specified, depending on the characteristics of the layers and their interfaces. The energies of localized states have been found that do not exist in a symmetric structure without a wave interacting with the interfaces of the layers. Moreover, the presence of a nonlinear response of the boundaries is mandatory. It is shown that the interaction of a wave with the interfaces of the layers can lead to the absence of a localized state in a one-dimensional symmetric potential well with infinitely high walls and a nonlinear response. The influence of the media parameters and their interfaces on the flux carried by surface waves has been analyzed.

scholarly journals Two Types of Localized States in a Photonic Crystal Bounded by an Epsilon Near Zero Nanocomposite

2018 ◽  
Author(s):  
Rashid G. Bikbaev ◽  
Stepan Ya. Vetrov ◽  
Ivan V. Timofeev
Keyword(s):  
Photonic Crystal ◽  
Defect Mode ◽  
Localized States ◽  
Simultaneous Formation ◽  
One Dimensional ◽  
Nanocomposite Layer ◽  
Localized State ◽  
Plasmon Polariton ◽  
Field Localization ◽  
First Time

The spectral properties of a one-dimensional photonic crystal bounded by a resonant absorbing nanocomposite layer with the near-zero permittivity have been studied. The problem of calculating the transmittance, reflectance, and absorptance spectra of such structures at the normal and oblique incidence of light has been solved. It is shown that, depending on the permittivity sign near zero, the nanocomposite is characterized by either metallic or dielectric properties. For the first time, the possibility of simultaneous formation of the Tamm plasmon polariton at the photonic crystal/metallic nanocomposite interface and the localized state similar to the defect mode with the field intensity maximum inside the dielectric nanocomposite layer is demonstrated. Specific features of field localization at the Tamm plasmon polariton and defect mode frequencies are analyzed.

Localized states in symmetric three-layered structure consisting of linear layer between focusing media separated by interfaces with nonlinear response

2019 ◽  
Vol 33 (11) ◽  
pp. 1850127
Author(s):  
S. E. Savotchenko
Keyword(s):  
Nonlinear Response ◽  
Mathematical Formulation ◽  
Localized States ◽  
Stationary States ◽  
Nonlinear Media ◽  
One Dimensional ◽  
Symmetric Structure ◽  
Linear Layer ◽  
Dimensional Boundary ◽  
Interface Parameters

We analyze the localization in three-layered symmetric structure consisting of linear layer between focusing nonlinear media separated by nonlinear interfaces. The mathematical formulation of the model is a one-dimensional boundary value problem for the nonlinear Schrödinger equation. We find nonlinear localized states of two types of symmetry. We derive the energies of obtained stationary states in explicit form. We obtain the localization energies as exact solutions of dispersion equations choosing the amplitude of the interface oscillations as a free parameter. We analyze the conditions of their existence depending on the combination of signs of interface parameters.

scholarly journals Особенности локализации возбуждений вблизи прослойки между нелинейными фокусирующими средами с нелинейным взаимодействием с границами раздела слоев

2020 ◽  
Vol 62 (3) ◽  
pp. 457
Author(s):  
С.Е. Савотченко
Keyword(s):  
Nonlinear Response ◽  
Layer Structure ◽  
Finite Thickness ◽  
Localized States ◽  
Characteristic Scale ◽  
Nonlinear Crystals ◽  
Field Localization

The localized states in a three-layer structure consisting of two nonlinear crystals with positive nonlinearity, between which a linear plate of finite thickness is clamped, and the layer interfaces are characterized by a nonlinear response are arised. The frequencies of such localized states are obtained that exist only at different values of the intensity of interaction of the layer interfaces with excitations. The conditions for the existence of such states are found and estimates of the characteristic scale of field localization are obtained.

scholarly journals Two Types of Localized States in a Photonic Crystal Bounded by an Epsilon near Zero Nanocomposite

Photonics ◽  
2018 ◽  
Vol 5 (3) ◽  
pp. 22 ◽  
Author(s):  
Rashid Bikbaev ◽  
Stepan Vetrov ◽  
Ivan Timofeev
Keyword(s):  
Photonic Crystal ◽  
Defect Mode ◽  
Localized States ◽  
Intensity Maximum ◽  
Simultaneous Formation ◽  
One Dimensional ◽  
Nanocomposite Layer ◽  
Localized State ◽  
Plasmon Polariton ◽  
Field Localization

The spectral properties of a one-dimensional photonic crystal bounded by a resonant absorbing nanocomposite layer with the near-zero permittivity have been studied. The problem of calculating the transmittance, reflectance, and absorptance spectra of such structures at the normal and oblique incidence of light has been solved. It is shown that, depending on the permittivity sign near zero, the nanocomposite is characterized by either metallic or dielectric properties. The possibility of simultaneous formation of the Tamm plasmon polariton at the photonic crystal/metallic nanocomposite interface and the localized state similar to the defect mode with the field intensity maximum inside the dielectric nanocomposite layer is demonstrated. Specific features of field localization at the Tamm plasmon polariton and defect mode frequencies are analyzed.

Effect of Biquadratic Exchange on Two Magnon States of Heisenberg Ferromagnets: Other Neighbor Exchange

1975 ◽  
Vol 53 (6) ◽  
pp. 637-647 ◽  
Author(s):  
D. A. Pink ◽  
Vijay Sachdeva
Keyword(s):  
Ground State ◽  
Nearest Neighbor ◽  
Ferromagnetic State ◽  
Localized States ◽  
Heisenberg Ferromagnet ◽  
Green Functions ◽  
Localized Modes ◽  
One Dimensional ◽  
Localized State ◽  
Biquadratic Exchange

We have investigated the two magnon localized states of a one dimensional Heisenberg ferromagnet the Hamiltonian of which is made up of nearest neighbor and next nearest neighbor isotropic bilinear and biquadratic exchange terms, and a single ion anisotropy term. We have restricted our choice of parameters so that the ground state at T = 0 is the fully aligned ferromagnetic state and we have used the thermodynamic Green functions where the averages have been evaluated in the ground state so that our results are good for [Formula: see text]. We have evaluated the probabilities of finding two spin deviations a distance n apart when the system is in a localized state described by total wave vector q. We have (a) compared the effects of ferromagnetic and antiferromagnetic next nearest neighbor exchange, (b) found that localized modes can lie below or above the two free magnon band depending upon the sign and magnitude of the biquadratic exchange, (c) found that in certain cases two spin deviations appear to behave like objects interacting only via a soft core, and (d) found that modes can have a large single ion component when the single ion anisotropy is zero.

scholarly journals Влияние эффектов самовоздействия на распространение импульсов поверхностных магнитостатических волн в структуре магнонный кристалл--диэлектрик--металл

2019 ◽  
Vol 89 (11) ◽  
pp. 1719
Author(s):  
С.Л. Высоцкий ◽  
Е.С. Павлов ◽  
А.В. Кожевников ◽  
Г.М. Дудко ◽  
Ю.А. Филимонов ◽  
...  
Keyword(s):  
Surface Waves ◽  
Anomalous Dispersion ◽  
Bragg Resonance ◽  
Frequency Range ◽  
Dielectric Thickness ◽  
One Dimensional ◽  
Action Effects ◽  
Dispersion Region ◽  
Magnonic Crystal

The influence of self-action effects on the magnetostatic surface waves (MSSW) pulses propagating in the structure of a one-dimensional magnonic crystal - dielectric - metal, where the choice of dielectric thickness forms an anomalous dispersion region that provides the fulfillment of Lighthill criterion on MSSW solitons formation, is studied. It is shown that in those cases when the portion of anomalous dispersion caused by metallization coincides with the frequency range of Bragg resonance, MSSW solitons are not formed.

scholarly journals Parameterization of localized states of liquid surface waves in non-Bragg structures

2021 ◽  
Vol 25 ◽  
pp. 104190
Author(s):  
Joshua Masinde Kundu ◽  
Ting Liu ◽  
Jia Tao ◽  
Ya-Xian Fan ◽  
Zhi-Yong Tao
Keyword(s):  
Surface Waves ◽  
Liquid Surface ◽  
Localized States ◽  
Bragg Structures ◽  
Liquid Surface Waves

Effect of Double Defects on Transmission Spectra of One-Dimensional Photonic Crystals

2010 ◽  
Vol 663-665 ◽  
pp. 725-728 ◽  
Author(s):  
Yuan Ming Huang ◽  
Qing Lan Ma ◽  
Bao Gai Zhai ◽  
Yun Gao Cai
Keyword(s):  
Photonic Crystals ◽  
Band Gap ◽  
Theoretical Calculations ◽  
Stop Band ◽  
Band Gaps ◽  
Characteristic Matrix ◽  
Frequency Range ◽  
Defect Band ◽  
One Dimensional ◽  
The One

Considered the model of the one-dimensional photonic crystals (1-D PCs) with double defects, the refractive indexes (n2’, n3’ and n2’’, n3’’) of the double defects were 2.0, 4.0 and 4.0, 2.0 respectively. With parameter n2=1.5, n3=2.5, by theoretical calculations with characteristic matrix method, the results shown that for a certain number (14 was taken) of layers of the 1-D PCs, when the double defects abutted, there was a defect band gap in the stop band gap, while when the double defects separated, there occurred two defect band gaps in the stop band gap; besides, with the separation of the two defects, the transmittance of the double defect band gaps decreased gradually. In addition, in this progress, the frequency range of the stop band gap has a little increase from 0.092 to 0.095.

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