All Questions
Tagged with electromagnetism condensed-matter
195
questions
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Permittivity real and imaginary parts with similar value possible?
Here's the context; I'm studying biological tissues that are supposed to behave like dielectrics. Using the modified cole-cole equation for theoretical predictions:
$$\tilde{\varepsilon}_r (\omega )= \...
- 189
3
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1
answer
62
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Are superinsulators perfect dielectrics?
In Wikipedia its stated: "The phenomenon of superinsulation can be regarded as an exact dual to superconductivity."
I understand that superinsulators are terrible conductors. But its not ...
- 2,989
2
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1
answer
59
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Does there exist a superinsulating dual to quantum flux pinning?
The phenomenon of flux pinning is well documented in popular science. It essentially arises from the fact that a superconductor expels all magnetic fields unless the field travels through a very small ...
- 2,989
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0
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44
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Does a superconductor with fewer defects flux pin more strongly?
In Jasper's answer its stated that the energy to move a flux-pinned superconductor goes into re-arranging the flux tubes that are passing through defects. In particular it's stated that it takes ...
- 2,989
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42
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How can red LEDs still give a faint glow at a voltage of only 1.4V? [duplicate]
How can a red LED work at a voltage of only $1.4{\rm V}$? Red photons have an energy of $1.77{\rm V}$ if we use $\lambda = 0.7\mu\text{m}$ in the relation:
$$ E = \hbar \omega = \frac{2\pi\hbar c}{\...
- 4,912
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36
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Differential magnetic susceptibility v.s. magnetic susceptibility?
For a given material which has the M-H curve looks like the following figure:
When I extract the magnetic susceptibility of the material, should I use the ratio between M and H, $\chi_m=\frac{M}{H}$, ...
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28
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Optical properties of non-Newtonian fluids
I'm interested in understanding the distinctions between non-Newtonian fluids and regular Newtonian fluids regarding their optical properties, including refractive index, nonlinear optical behavior (...
- 342
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85
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I can't find this article
Does anyone know the DOI of the article below or where I can download it?
P. Rhodes and G. Rowlands, “Demagnetising energies of uniformly
magnetized rectangular blocks,” Proc. Leeds Phil. Lit. Soc., ...
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2
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102
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Definition of Hall's current
Dear fellow physicists!
I come to you with a question regarding the definiton of the Hall current.
The only sentence close to definition of this concept, I have found after extensive search on the ...
- 1
1
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0
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22
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Would flux tubes be prevented from passing through a sufficiently thick superinsulating layer?
Suppose you have a type-2 superconducting cube with a thick superinsulating layer passing through the middle of the cube; visualized below with (grey superconducting mass, violet superinsulator in ...
- 2,989
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32
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Assuming vortex defect pinning is equal, and number of tubes are equal should longer flux tubes lead to stronger pinning?
Suppose you have two superconductors that resemble rectangular prisms with identical width and length. The first superconductor call it $A$ is shorter than $B$ visualized below:
Now both $A$ and $B$ ...
- 2,989
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If you embed an extremely thin magnetic strip in superconducting block do supercurrents form around the strip?
Given a superconducting block (lets assume type 1) in grey below and a very thin magnetic strip with a simple magnetic dipole structure (in blue below) inserted into the block. If we were to cool the ...
- 2,989
1
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0
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63
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Applying magnetic field to magnetite
I’m an undergrad whose not actually studied this content yet in a lecture series but I'm doing an experiment and I am confused on a result. So, the basic idea is, I heated and then cooled bulk ...
- 13
5
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3
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285
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“Emergent magnetic monopole” discovered (5th December 2023)
Looks like a few days ago (5th December 2023) a research team discovered “emergent magnetic charge” in antiferromagnetic materials, and the result was published on Nature Materials.
The finding was ...
- 687
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Quantum master equation for light in medium with dissipation
The effective theory of photons in medium is usually obtained by inserting the electric susceptibility $\chi$ (linear or nonlinear) into $\int \mathrm{d}{\mathbf{D}} \cdot \mathbf{E}$ and complete the ...
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