Artificial materials with $\varepsilon$ and $\mu$ not found in nature. The "atoms" are sub-wavelength. Includes negative-index materials, superlenses, split-ring resonators, wire media and backwards wave propagation.
Questions tagged [metamaterials]
31 questions
4
votes
4 answers
Can invisibility be achieved through physics?
I’ve been reading about the concept of invisibility in physics and am curious about its feasibility. We often see references to invisibility cloaks in science fiction, but what does physics say about it? Are there any existing theories or…
ᕼᗩᗪI ᑕᕼ
- 79
3
votes
1 answer
Can the refractive index of a medium be negative?(<0)
Recently I was asked in a test what would happen if the refractive index of a medium was negative. Is it possible really? The refractive index is the ratio of the speed of light in a vacuum and another medium. It can't be less than $1$ also the…
Sukuna
- 41
3
votes
2 answers
Perfect reflection with metamaterials with indices of refraction less than one
Total internal reflection is used to send light signals long distances in fiber-optic cables. If the cable is shaped into a ring, the light will run in a circle until its intensity dwindles due to attenuation (optical ring resonators are examples of…
2
votes
3 answers
In order to cool below the ambient air temperature using passive radiative cooling during daytime why is it important to radiate heat into space?
Why not radiate it instead of the surrounding air, like Air conditioners?
I know an air conditioner does not transfer/dump heat to the outside by radiation, but by phase transformation-specifically condensation..but AC's do dump heat into their…
2
votes
2 answers
How derive a spring constant of a helically turned helix based on elasticity of the material and the geometry?
The structure has helicities on two levels and looks like the tungsten wire in an incandescent light bulb:
How, if at all, can the spring constant be derived from elastic properties of the material, the pitch of the two helicies and the three radii…
David Jonsson
- 1,086
2
votes
0 answers
List of complex refractive indices for various frequencies and various materials
I want a list of refractive index values for various materials (or even a single material) for various frequencies / wavelengths (I need this specifically for the micro wave - radio wave regions of the spectrum). I have searched the internet for the…
Babaji
- 172
1
vote
0 answers
Snell's law in materials having negative permittivity only?
We have reverse Snell's law in negative index materials (having negative permittivity and permeability). If we have a material with only negative permittivity , then can we also have reverse Snell's law in this case?
MB1
- 11
1
vote
0 answers
Help with Parametrizing Path Through High-Symmetry Points in 2D Hexagonal Brillouin Zone
I'm currently working on a project involving the calculation of band structures for a 2D hexagonal lattice, and I need some guidance on how to properly parametrize a path that covers the high-symmetry points in the Brillouin zone.
Specifically, I am…
1
vote
0 answers
What photonic properties of a subwavelength plasmonic cavity make it generate saturated structural colour in just one layer?
I have a photonics question regarding a paper I am reading. Physics is not my area of study so please be kind :))
https://doi.org/10.1126/sciadv.adf7207
In this paper, the group has fabricated a self-assembled sub wavelength plasmonic cavity that…
anfjnn
- 11
- 1
1
vote
2 answers
Is it possible to make invisibility cloak in real?
I am a materials science undergraduate student. I have a question out of curiosity if it is possible to make a material that can completely make things invisible? What are the problems we will face in making it?
How can we achieve it?
UJM
- 163
- 6
1
vote
0 answers
Why dispesion relation in a 2d plane related to the poles of green's function?
I'm looking at a paper about deriving the dispersion relation in a metasurface, the paper claims that
'The modes supported by an anisotropic metasurface are provided by the poles of the Green’s
function.'
I'm confused with it, can someone…
1
vote
1 answer
What is the difference between ordinary-spacial cloaking and spacetime cloaking?
I am unsure of what are the differences between space time cloaking and spacial cloaking, as any event can be hidden from a viewer using spatial cloaking for however long the cloaking is activated, from my understanding. What is the difference…
H_Boofer
- 124
1
vote
0 answers
FDTD simulations for metamaterials and complex refractive index
I have designed a working FDTD code to simulate electromagnetic wave propagation using Yee's algorithm. I have been able to place materials such as glass slabs, etc which have positive and real refractive indices and then look at the waves as they…
Babaji
- 172
1
vote
1 answer
What is a Material Called that Translates the Image of a Touching Object's Surface?
What is the name of a material that moves light through it in such a way that it appears that the surface of an object has translated through the material? Also, what is an example of this type of material?
From very distant memory, I think this…
Tallima
- 111
1
vote
1 answer
Induced EMF in metamaterial
I am reading JB Pendry's original paper on metamaterials (Magnetism from Conductors,
and Enhanced Non-Linear Phenomena) and I am really having some trouble understanding just a few of his mathematical steps and was wondering if anyone could help me…
user41178
- 1,001