scholarly journals On the possibility of superluminal energy propagation in a hyperbolic metamaterial of metal-dielectric layers

AIP Advances ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 015106 ◽  
Author(s):  
Pi-Gang Luan ◽  
Jie-Luen Wu
Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 863
Author(s):  
Pi-Gang Luan

In this work, we study the dynamical behaviors of the electromagnetic fields and material responses in the hyperbolic metamaterial consisting of periodically arranged metallic and dielectric layers. The thickness of each unit cell is assumed to be much smaller than the wavelength of the electromagnetic waves, so the effective medium concept can be applied. When electromagnetic (EM) fields are present, the responses of the medium in the directions parallel to and perpendicular to the layers are similar to those of Drude and Lorentz media, respectively. We derive the time-dependent energy density of the EM fields and the power loss in the effective medium based on Poynting theorem and the dynamical equations of the polarization field. The time-averaged energy density for harmonic fields was obtained by averaging the energy density in one period, and it reduces to the standard result for the lossless dispersive medium when we turn off the loss. A numerical example is given to reveal the general characteristics of the direction-dependent energy storage capacity of the medium. We also show that the Lagrangian density of the system can be constructed. The Euler–Lagrange equations yield the correct dynamical equations of the electromagnetic fields and the polarization field in the medium. The canonical momentum conjugates to every dynamical field can be derived from the Lagrangian density via differentiation or variation with respect to that field. We apply Legendre transformation to this system and find that the resultant Hamiltonian density is identical to the energy density up to an irrelevant divergence term. This coincidence implies the correctness of the energy density formula we obtained before. We also give a brief discussion about the Hamiltonian dynamics description of the system. The Lagrangian description and Hamiltonian formulation presented in this paper can be further developed for studying the elementary excitations or quasiparticles in other hyperbolic metamaterials.


2014 ◽  
Vol 3 (2) ◽  
pp. 6
Author(s):  
S. Kozik ◽  
M. A. Binhussain ◽  
A. Smirnov ◽  
N. Khilo ◽  
V. Agabekov

The main goal of this work was to introduce simple model of surface roughness which does not involve objects with complicated shapes and could help to reduce computational costs. We described and proved numerically that the influence of surface roughness at the interfaces in metal-dielectric composite materials could be described by proper selection of refractive index of dielectric layers. Our calculations show that this model works for roughness with RMS value about 1 nm and below.


2014 ◽  
Vol 22 (12) ◽  
pp. 14975 ◽  
Author(s):  
Andrei Andryieuski ◽  
Sergei V. Zhukovsky ◽  
Andrei V. Lavrinenko

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2301
Author(s):  
Ping Gu ◽  
Yuheng Guo ◽  
Jing Chen ◽  
Zuxing Zhang ◽  
Zhendong Yan ◽  
...  

We theoretically study the multiple sharp Fano resonances produced by the near-field coupling between the multipolar narrow plasmonic whispering-gallery modes (WGMs) and the broad-sphere plasmon modes supported by a deep-subwavelength spherical hyperbolic metamaterial (HMM) cavity, which is constructed by five alternating silver/dielectric layers wrapping a dielectric nanosphere core. We find that the linewidths of WGMs-induced Fano resonances are as narrow as 7.4–21.7 nm due to the highly localized feature of the electric fields. The near-field coupling strength determined by the resonant energy difference between WGMs and corresponding sphere plasmon modes can lead to the formation of the symmetric-, asymmetric-, and typical Fano lineshapes in the far-field extinction efficiency spectrum. The deep-subwavelength feature of the proposed HMM cavity is verified by the large ratio (~5.5) of the longest resonant wavelength of WGM1,1 (1202.1 nm) to the cavity size (diameter: 220 nm). In addition, the resonant wavelengths of multiple Fano resonances can be easily tuned by adjusting the structural/material parameters (the dielectric core radius, the thickness and refractive index of the dielectric layers) of the HMM cavity. The narrow linewidth, multiple, and tunability of the observed Fano resonances, together with the deep-subwavelength feature of the proposed HMM cavity may create potential applications in nanosensors and nanolasers.


Author(s):  
R.W. Carpenter

Interest in precipitation processes in silicon appears to be centered on transition metals (for intrinsic and extrinsic gettering), and oxygen and carbon in thermally aged materials, and on oxygen, carbon, and nitrogen in ion implanted materials to form buried dielectric layers. A steadily increasing number of applications of microanalysis to these problems are appearing. but still far less than the number of imaging/diffraction investigations. Microanalysis applications appear to be paced by instrumentation development. The precipitation reaction products are small and the presence of carbon is often an important consideration. Small high current probes are important and cryogenic specimen holders are required for consistent suppression of contamination buildup on specimen areas of interest. Focussed probes useful for microanalysis should be in the range of 0.1 to 1nA, and estimates of spatial resolution to be expected for thin foil specimens can be made from the curves shown in Fig. 1.


Author(s):  
Matthew R. Libera ◽  
Martin Chen

Phase-change erasable optical storage is based on the ability to switch a micron-sized region of a thin film between the crystalline and amorphous states using a diffraction-limited laser as a heat source. A bit of information can be represented as an amorphous spot on a crystalline background, and the two states can be optically identified by their different reflectivities. In a typical multilayer thin-film structure the active (storage) layer is sandwiched between one or more dielectric layers. The dielectric layers provide physical containment and act as a heat sink. A viable phase-change medium must be able to quench to the glassy phase after melting, and this requires proper tailoring of the thermal properties of the multilayer film. The present research studies one particular multilayer structure and shows the effect of an additional aluminum layer on the glass-forming ability.


Author(s):  
L. Gbahoué ◽  
S. Lecume ◽  
J.L. Carreau ◽  
Ph. Hobbes ◽  
F. Roger
Keyword(s):  

Author(s):  
D. Zudhistira ◽  
V. Viswanathan ◽  
V. Narang ◽  
J.M. Chin ◽  
S. Sharang ◽  
...  

Abstract Deprocessing is an essential step in the physical failure analysis of ICs. Typically, this is accomplished by techniques such as wet chemical methods, RIE, and mechanical manual polishing. Manual polishing suffers from highly non-uniform delayering particularly for sub 20nm technologies due to aggressive back-end-of-line scaling and porous ultra low-k dielectric films. Recently gas assisted Xe plasma FIB has demonstrated uniform delayering of the metal and dielectric layers, achieving a planar surface of heterogeneous materials. In this paper, the successful application of this technique to delayer sub-20 nm microprocessor chips with real defects to root cause the failure is presented.


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