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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Why is there a superconducting dome in superconductors?

Generally speaking, by the well-known BCS theory, the more carrier density( density of state at Fermi surface) leads to higher critical temperature. However, in many researches, people fond that the ...
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Formation of vortices in superconductors

So I'm trying to understand how mixed state of a type II superconductor becomes the energetically favourable state. I've been through a simple approximate calculation considering a S-N boundary to ...
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Are quantum computers at least build able?

Assuming a highly unrealistic where you basically have unlimited money to burn. Is it possible to a build a size scalable quantum computer? My premise is that I often read tha people have a made a ...
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Eddy current brake with superconductor

There are eddy current brakes used with metal plates to stop trains. It converts kinetic energy of the metal plate to heat via eddy current on it. So what if we have a superconducting metal plate and ...
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Shorting a Superconducting Coil with A/C

When a superconducting coil carrying a direct current is shorted, it continues to carry the current without loss (approximately), assuming it stays cooled and superconducting. What would happen if ...
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Procedure for wrapping a superconducting coil around a cylindrical shell?

I don't know if experimental physics questions are allowed on this site - please direct me to the proper SE if it doesn't belong here. I need to wrap a few layers of superconducting wire (~80 ...
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Number Conserving Superconductors

Usual BCS theory used to describe superconductors violates particle number conservation, this is allowed since that theory is written in a grand canonical ensemble (i.e particles can be exchanges ...
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Superconductivity and superfluidity energy dissipation

All articles say that in superconductive state, the materials have exactly zero resistance, but is this the case in real life experiment?, because if this were true, a process without energy ...
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Bogoliubov de Gennes Hamiltonian, Expansion of electron operator

Suppose we are given a particle-hole symmetric Hamiltonian H. This type of Hamiltonian is usually diagonalized by a Bogoliubov transformation. In this context in the literature the local electron ...
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Synthesis of Fe-based superconductors

Polycrystal cuprate superconductors are generally prepared by solid state reactions: Starting reagents are in powder form, they are mixed to each other and placed into furnace on high temperature (...
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Is the current density ${\bf j}$ an observable?

The current density ${\bf j}$ is most easily defined from$$ I = \int_{\text{cross-section} \atop \text{of wire}} \textbf{j}\cdot d\textbf{S}, $$ where $I$ is the current flowing through the wire. From ...
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Eigenvector distributions, random matrix theory and the ten-fold way

For various applications the distribution of components of the eigenvectors of random matrices is of interest. For example, in the case of a matrix in the Gaussian orthogonal ensemble this ...
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Why does a magnet rise up from the surface of a superconductor after the superconductor reaches critical temperature?

From my current understanding, when a magnet is placed above a superconductor below Tc, it hovers due to the Miessner Effect (total exclusion of magnetic fields from within the superconductor) due to ...
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superconducting coherence length explanation

What is the formula for superconducting pair coherence length in real space? How is it calculated in a two-dimensional square lattice? I found this formula below: $$\zeta = \frac{\sum_{\bf{r}}r^2 \...
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Wavefunction for Anti-Pfaffian state

What is the most general form of a wavefunction for anti-Pfaffian in variables $\{z_i\}$ which represent the positions of electrons on a two dimensional plane?
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Flywheel energy storage: Why not use room temperature diamagnets instead of superconductors?

Flywheel energy storage has garnered some interest from academia and industry for its potential to store surplus electrical energy efficiently in kinetic form. Modern designs use magnetic bearings ...
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Definition of Josephson current

Consider a system of two superconductors (with Hamiltonian $H_{SC1}$ and $H_{SC2}$) weakly tunnel coupled via some intermediate system, i.e. an insulator, a ferromagnet, a quantum dot, etc. (described ...
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Does the Mermin-Wagner theorem forbid superconductivity in the 2D Hubbard-Model?

"In the 2D Hubbard model (two spatial dimensions) the Mermin-Wagner theorem does not allow a phase transition." I am quite illiterate concerning this theorem and hearsay. Does the theorem apply to a ...
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Is a flexible space tower using coaxial superconducting rings possible?

Suppose we stack coaxially, vertically a large number of rings, made of some high temperature superconducting material, and start a current through each of the rings in alternate directions (e.g. the ...
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Are photons inside the media massive? If yes, why there is no Meissner effect?

We all know in vacuum travels with speed $c$, hence its rest mass has to be 0. In the media the light speed $v<c$. Then the photon renormalized by the medium (call it "quasi-photon" if you like), ...
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Superconducting condensation energy from diamagnetic levitation

Suppose you had a classic setup in which a magnet is held over above a high-temperature superconductor which is then cooled down to its critical temperature so that it starts to superconduct and the ...
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Underdoped Cuprates

What does underdoped cuprates mean? I guess cuprate is underdoped when hole concentration is less then optimal doping. Am I Right?. or it is something difference?
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How dopant enhances the superconductivity of BSCCO

i really need your help, I want to know the effect of Dopant (for Example Manganese) in BSCCO (for example Bi-2212) in Resistivity? i read some articles saying it increases the critical temperature ...
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What happens to a superconductor levitated by a spinning magnet?

What happens to a superconductor that is being levitated by a magnet that is spinning? Will the superconductor be stable or oscillate?
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Do magnets also attract super conductors?

If a superconductor can be repelled by a magnet (or, well, locked in a certain position by the magnet) can a magnet be attracted to a superconductor. What would happen if you take a peace of metal, ...
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How to choose which atoms to cool using optical cooling technology?

Which atoms are easiest to cool down to very low temperatures (e.g. mK)? Which quantities does one need to look at? My very naive guesses so far are: Their mass: the heavier they are they least ...
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Can hydrogen be used for superconductors?

I learned that heaver isotopes of a substance have a lower superconductivity transition temperature. Does this mean that things like hydrogen which are lighter can be used for high temperature ...
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Superconductivity: how does the critical temperature depend on the pressure?

This question is inspired by a recent publication, in which researchers managed to boost the record critical temperature at which a substance becomes superconducting by applying an enormous pressure ...
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What is a Fermi arc?

What is meant with a Fermi arc in the context of Weyl semimetals? Is this the just a one-dimensional Fermi surface? For example, in electron-doped graphene, the Fermi surface consists of 2 disjoint ...
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Could the assumption of superconductivity explain unexplained geomagnetic behaviors?

Science recently published an article regarding a new discovery in superconductivity; that the metallic form of hydrogen sulfide is superconducting at high temperature (relative to absolute zero). I'...
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Shape of the spin part in the superconducting gap

The conventional way of writing down the gap in a superconducting material $\Delta(k) = \langle \hat{c}_\alpha({\bf k}) \hat{c}_\beta({\bf -k}) \rangle$ is $$\Delta(k) = (\Delta_0(k) + {\bf d(k) \...
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properties of p-wave superconductors in a self consistent calculation

2D p+ip superconductors have zero energy mid-gap modes localized at the boundaries as well as in the vortex cores as pointed out in several places such as Read, Green and Ivanov. The modes result in ...
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Energy in conductors with $\vec{E}$-field

The question is deceptively simple. Suppose I have a uniform circular wire in which I have created the a E-field by some mean. We that without the source the electric field should not be there, so if ...
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Why is there a band structure for strongly correlated systems?

The existence of band structure of a crystalline solid comes from the Bloch theorem, which relies on the independent-electron approximation. Why do people still talk about the band structure for a ...
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Which part of a real Type II Superconductor magnetization loop represents the Meissner state?

So if we consider an ideal type II superconductor the magnetization should look like this The Meissner state is to be found between $0$ and $H_{c1}$ and the superconductor works as an ideal ...
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Is this “theory” of high-temperature superconductivity scientifically correct?

I came across a video: New theory of high-temperature superconductivity The "theory" states that as a atom is covalently bonded to another the electrons move around the both atoms in a probabilistic ...
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Meaning of the term 'bulk'

I have recently started reading literature on 2 dimensional systems in Condensed matter. While reading, I frequently came across the word 'bulk'. Sometimes it referred to 2-D and sometimes to 3-D. I ...
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Would a super conductive insulation completely prevent the propagation of a magnetic field from a wire where it is wrapped around?

I have limited understanding about super conductors and see them as expelling magnetic fields purely due to eddy currents produced without resistance opposite the magnetic field. I have read that ...
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Why is there an energy gap in superconductors?

I'm a little out of my depth here... I'm trying to understand quasiparticle tunnelling in superconductor-insulator-superconductor junctions. Many books use the "semiconductor model" to explain this: ...
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Is an electron a superconductor?

A superconductor has zero resistance. What about an electron in a vacuum? Could this simple system be considered superconducting?
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What is the $D_{x^2-y^2}$ symmetry/channel/instabilitied referred to with regards to super-conductivity?

I have been reading various articles on Renormalization group where they compute the flow of some parameter which becomes increasingly attractive and then say that parameter is responsible for Cooper ...
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Basic questions about the Kitaev chain

I am trying to understand the first 5 pages of Introduction to topological superconductivity and Majorana fermions http://arxiv.org/abs/1206.1736 I read it 2-3 times and thought about it but a few ...
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Books on superconductivity and its relation to spontaneous symmetry breaking

I wish to understand more about the relationship between superconductivity and spontaneous symmetry breaking. I would also appreciate sources for learning about symmetry breaking and particles in more ...
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How is superconducting coherence length measured in experiment?

In a superconductor, the coherence length measure the mean distance between two electrons in the Cooper pair. How is the coherence length experimentally measured?
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Why do Superconductors make Magnetic Fields Bend Away

When superconductors reach their "threshold temperature" their electrical resistance turns 0. This makes the magnetic field lines not pass through the superconductor but instead bend itself around it ...
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current splitting in the presence of superconductors

When you have two resistors in parallel, the current splits up based on the resistances. What will happen if we have two superconductors in place of the resistors? What will happen to the current?
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Interpolation formula for BCS superconducting gap

In BCS theory, the superconducting gap is given by solving at different temperatures the integral $$\frac{1}{N(0)V}=\int_0^{\hbar\omega_c}\frac{\tanh\frac{1}{2}\beta(\xi^2+\Delta^2)^{1/2}}{(\xi^2+\...
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Superconductor in a parallel vs perpendicular magnetic field

My question concern's the huge difference in critical fields regarding a thin superconductor(SC) which is surrounded by a magnetic field. lets imagine the SC is a thin film in the x-y Plane: Applying ...
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What is the difference between a Josephson junction and a superconducting tunnel junction?

I am wondering if there is any difference between a Josephson junctions and superconducting tunnel junctions. I appreciate a good explanation.
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Are there topological non-trivial states in zero dimension?

The periodic table of topological insulators and superconductors suggests that there can be topological non-trivial phases in zero dimension in non-interacting system with certain symmetries. A 0D ...