Topological interface states in translational metamaterials for sub-wavelength in-plane waves

2021 ◽  
Vol 197 ◽  
pp. 106308
Author(s):  
Yijie Liu ◽  
Liang Jin ◽  
Hongfa Wang ◽  
Dongying Liu ◽  
Yingjing Liang
Author(s):  
Arnold Abramov ◽  
Yutao Yue ◽  
Mingming Wang ◽  
Zongyang Wang ◽  
Yajun Xu

The scattering of electromagnetic plane waves by triangular prism and its truncated form (the isosceles triangle and the trapezoid are transverse sections, respectively) has been studied in order to determine possibility of high field intensity (photonic jet) formation. Using high-resolution finite-difference time-domain simulation, an optimal relationship between the wavelength and the size of the prism was found to form photonic jet with sub wavelength waist on the shadow side of the prism. Truncation of the prism (with trapezoids as transverse sections) leads to an improvement in the characteristics of photonic jets (intensity, length and waist). A qualitative explanation of the simulation results obtained is presented.


Author(s):  
E. Martini ◽  
M. Mencagli ◽  
S. Maci

Metasurfaces (MTSs) constitute a class of thin metamaterials used for controlling plane waves and surface waves (SWs). At microwave frequencies, they are constituted by a metallic texture with elements of sub-wavelength size printed on thin grounded dielectric substrates. These structures support the propagation of SWs. By averaging the tangential fields, the MTSs can be characterized through homogenized isotropic or anisotropic boundary conditions, which can be described through a homogeneous equivalent impedance. This impedance can be spatially modulated by locally changing the size/orientation of the texture elements. This allows for a deformation of the SW wavefront which addresses the local wavevector along not-rectilinear paths. The effect of the MTS modulation can be analysed in the framework of transformation optics. This article reviews theory and implementation of this MTS transformation and shows some examples at microwave frequencies.


Author(s):  
Xudong Weng ◽  
O.F. Sankey ◽  
Peter Rez

Single electron band structure techniques have been applied successfully to the interpretation of the near edge structures of metals and other materials. Among various band theories, the linear combination of atomic orbital (LCAO) method is especially simple and interpretable. The commonly used empirical LCAO method is mainly an interpolation method, where the energies and wave functions of atomic orbitals are adjusted in order to fit experimental or more accurately determined electron states. To achieve better accuracy, the size of calculation has to be expanded, for example, to include excited states and more-distant-neighboring atoms. This tends to sacrifice the simplicity and interpretability of the method.In this paper. we adopt an ab initio scheme which incorporates the conceptual advantage of the LCAO method with the accuracy of ab initio pseudopotential calculations. The so called pscudo-atomic-orbitals (PAO's), computed from a free atom within the local-density approximation and the pseudopotential approximation, are used as the basis of expansion, replacing the usually very large set of plane waves in the conventional pseudopotential method. These PAO's however, do not consist of a rigorously complete set of orthonormal states.


1998 ◽  
Vol 184-185 (1-2) ◽  
pp. 1190-1194
Author(s):  
M Von Truchsess
Keyword(s):  

2020 ◽  
Vol 22 (4) ◽  
pp. 939-958
Author(s):  
Indrajit Roy ◽  
D. P. Acharya ◽  
Sourav Acharya

AbstractThe present paper investigates the propagation of quasi longitudinal (qLD) and quasi transverse (qTD) waves in a magneto elastic fibre-reinforced rotating semi-infinite medium. Reflections of waves from the flat boundary with surface stress have been studied in details. The governing equations have been used to obtain the polynomial characteristic equation from which qLD and qTD wave velocities are found. It is observed that both the wave velocities depend upon the incident angle. After imposing the appropriate boundary conditions including surface stress the resultant amplitude ratios for the total displacements have been obtained. Numerically simulated results have been depicted graphically by displaying two and three dimensional graphs to highlight the influence of magnetic field, rotation, surface stress and fibre-reinforcing nature of the material medium on the propagation and reflection of plane waves.


PIERS Online ◽  
2005 ◽  
Vol 1 (1) ◽  
pp. 37-41 ◽  
Author(s):  
Pavel A. Belov ◽  
C. R. Simovski

Author(s):  
Nathalie Deruelle ◽  
Jean-Philippe Uzan

This chapter examines solutions to the Maxwell equations in a vacuum: monochromatic plane waves and their polarizations, plane waves, and the motion of a charge in the field of a wave (which is the principle upon which particle detection is based). A plane wave is a solution of the vacuum Maxwell equations which depends on only one of the Cartesian spatial coordinates. The monochromatic plane waves form a basis (in the sense of distributions, because they are not square-integrable) in which any solution of the vacuum Maxwell equations can be expanded. The chapter concludes by giving the conditions for the geometrical optics limit. It also establishes the connection between electromagnetic waves and the kinematic description of light discussed in Book 1.


2003 ◽  
Vol 529 (3) ◽  
pp. 329-337 ◽  
Author(s):  
Tomohiro Kubota ◽  
Ján Ivančo ◽  
Masao Takahashi ◽  
Kenji Yoneda ◽  
Yoshihiro Todokoro ◽  
...  
Keyword(s):  
Band Gap ◽  

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