On reflection from a half-space with negative real permittivity and permeability: Time-domain and frequency-domain results

时变真空介电常数和磁导率的电磁学

Electromagnetics with time-varied vacuum permittivity and permeability

该研究假设真空介电常数和磁导率随时间指数增加，推导出时变电磁场麦克斯韦方程组，发现光速和电磁强度随时间减小，并预测吸收光谱红移，与哈勃观测一致。

Moving Targets Virtually Via Composite Optical Transformation

We propose a composite optical transformation to design an illusion device which can move the image of a target from one place to another place. Enclosed by such an illusion device, an arbitrary object located at one place appears to be at another place virtually. Different from the published shifted-position cloak which is composed of the left-handed materials with simultaneously negative permittivity and permeability, the illusion device proposed in this letter has positive permittivity and permeability. Hence proposed illusion device could be realized by artificial metamaterials.

On the Definition of Effective Permittivity and Permeability For Thin Composite Layers

The problem of definition of effective material parameters (permittivity and permeability) for composite layers containing only one-two parallel arrays of complex-shaped inclusions is discussed. Such structures are of high importance for the design of novel metamaterials, where the realizable layers quite often have only one or two layers of particles across the sample thickness. Effective parameters which describe the averaged induced polarizations are introduced. As an explicit example, we develop an analytical model suitable for calculation of the effective material parameters $ε_{\rm{eff}}…

The negative index of refraction demystified

We study electromagnetic wave propagation in mediums in which the effective relative permittivity and the effective relative permeability are allowed to take any value in the upper half of the complex plane. A general condition is derived for the phase velocity to be oppositely directed to the power flow. That extends the recently studied case of propagation in mediums for which the relative permittivity and relative permeability are both simultaneously negative, to include dissipation as well. An illustrative case study demonstrates that in general the spectrum divides into five distinct regi…

Soft-and-Hard/D'B' Boundary Conditions and their Realization by Electromagnetic Media

A layer of uniaxial medium with large axial permittivity and permeability can be used as a quarter-wave transformer with interesting properties. By increasing the transverse permittivity and permeability the transformer becomes a thin sheet. It is shown that the recently introduced SHDB boundary conditions, generalizing the soft-and-hard and DB conditions, realized by the interface of a skewon-axion medium, can be transformed to form a novel class of SHD'B' boundary conditions which generalizes the soft-and-hard and D'B' boundary conditions. Reflection of a plane wave from a planar SHD'B' boun…

真空电容率起源与光子传播时间涨落的零点能密度

Zero-Point Energy Density at the Origin of the Vacuum Permittivity and Photon Propagation Time Fluctuation

本文提出具有零点能密度的真空描述，解释真空电容率与磁导率起源，改进现有计算并测试虚拟涨落有限寿命模型，评估光子传播时间涨落，指出部分模型与天文观测冲突但相速度不受影响。

The quantum vacuum at the foundations of classical electrodynamics

In the classical theory of electromagnetism, the permittivity and the permeability of free space are constants whose magnitudes do not seem to possess any deeper physical meaning. By replacing the free space of classical physics with the quantum notion of the vacuum, we speculate that the values of the aforementioned constants could arise from the polarization and magnetization of virtual pairs in vacuum. A classical dispersion model with parameters determined by quantum and particle physics is employed to estimate their values. We find the correct orders of magnitude. Additionally, our simple…

Transparent Negative Index of Refraction Metamaterial Using a Wire Array in a Magnetic Host

We have made measurements of microwave transmission over the 12 - 18 GHz range and through a simple metamaterial exhibiting a negative index of refraction. The metamaterial consisted of an array of wires cladded in dielectric embedded in a magnetic ferrite. The ferrite replaced the cut-ring structure usually used to create the negative permeability. The dielectric cladding decoupled the ferrite from the wires, thereby allowing the wire array permittivity to be simultaneously negative with the permeability. The simplicity of the design allows for miniaturization of potential microwave devices b…