Questions tagged [superconductivity]
Superconductivity is the transmission of current with no resistive losses, and is one of the most active areas of condensed matter physics research.
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Is there a superfluid dual to superinsulators?
It's well known that there are many analogies between Superconductors and Superfluids. The diagram below explains a few:
$$ \begin{matrix} \bf{\text{Superconductors}} \\ \text{0 electrical resistance} ...
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How do high temperature superconductors behave at low temperatures (order of $\rm mK$)?
How do high temperature superconductors having $T_c \sim 90$K behave at low temperature (order of $\rm mK$)? Will it become paramagnetic? How does the interaction happen at low temperatures (range of $...
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Why are there no Goldstone modes in superconductor?
Usually, the absence of Goldstone modes in a superconductor is seen as an example of the Anderson-Higgs mechanism, related to the fact that there is gauge invariance due to the electromagnetic gauge ...
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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 ...
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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 ...
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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 ...
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Why do cryogenic temperatures usually result in higher conductivity, even (sometimes) superconductivity, but otherwise nonconductive Wigner crystals?
Wigner crystals are all the rage in the news, since around the start of the pandemic...
But at what temperatures (and pressures?) do these cold materials create a nonconducting 'Wigner crystal' rather ...
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How would you estimate the maximum weight that a superconductor can levitate?
The Meissner effect lets superconducting objects levitate, which is very cool. That it can enable levitation is a bit subtle, and involves flux pinning, which gets referenced in lots of places ...
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To ensure that there is no $E$-field inside the superconductor and Faraday's law holds true the surface current seems to eliminate its cause, why?
In a Faraday's induced EMF experiment with a superconducting loop, the current at the surface of the superconducting loop creates a magnetic field that nullifies the magnetic field created by the Bar-...
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Finding the phase difference in Rf-SQUID [closed]
In my solution I have assumed that $\phi_{12}$ and $\phi_{ab}$ are gauge invariant. This gives me a final expression where I need to insert the flux, which I set equal to $LI$.
I'm unsure which ...
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How can I build a superconductor at home?
How can I make a superconductor at home? I have been interested in making one from scratch, but I have no idea where to begin. I have heard about YBCO superconductors and I feel as though that is the ...
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Is it possible to have a system that show superconducting behavior in magnetization and insulating behavior in resistivity? [closed]
Is it possible to have a system that show superconducting behavior in magnetization measurements and insulating behavior in resistivity measurements? if yes then please provide some references? In ...
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Josephson relations when $V$ approaches the superconducting gap
The standard Josephson relations are $I = I_0 \sin(\phi)$ and $V = \phi_0 \dot{\phi} / 2\pi$. However these equations break down when $I$ exceeds $I_0$, or when $V$ exceeds $V_\text{gap} = 2\Delta / e$...
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Is Number Operator a Generalized Momentum?
In superconducting circuit, the number operator, $\hat{n}$, and phase operator, $\hat{\varphi}$ are conjugate pairs. Is $\hat{n}$ the canonical momentum, conjugate momentum, and also generalized ...
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Significance of the phase of the condensate as compared to that of the regular Fermi sea in the Anderson-Higgs mechanism
I do not fully understand how the phase of the charged Cooper pair condensate is different from the phase of e.g. the Fermi liquid in a regular metal.
The state of the metal (any quantum state really) ...
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