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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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, for example, 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 ...
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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). ...
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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

Vortices in 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 ...
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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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XRD and Superconducting Volume Phase

I have prepared H-Tc Superconductors polycrystalline samples. In the XRD pattern there is not extra peaks and we can say the sample is pure, without impurities. But SQUID shows that only 60% is ...
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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 ...
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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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A magnet floating due to Meissner effect

If a magnet is floating due to the Meissner effect, can the magnet rotate freely under influence of external field in spite of the presence of north and south pole in it ?
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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 ...
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How do Cooper pairs form?

How can Cooper pairs formation be possible, even though it is made up of two likely charged particles? (those particles being electrons)
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Chemical potential of Cooper pairs

Consider a BCS Hamiltonian with an additional term that reads: $i\mu c_k^+c_{-k}^+ + H.c$. What is the meaning of $\mu$? How one can write this term in real space, and does this term show up in the ...
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About Majorana fermion in spin-orbit coupled quantum wires

Majorana mode has attracted great theoretical and experimental interest. The experimental evidence is obtained in quantum wires. The origin theoretical proposals of quantum wires are the papers: 1、R. ...
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What determines the spatial variation in phase in a superconductor?

I'm assuming that since a superconductor is in one common wave function, the time evolution is governed by the typical global phase variation: $$ \psi (t) = e^{-\frac{i}{\hbar}E_nt}\psi(0) $$ ...
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physics of the beaker experiment for superfluid helium

here is an illustration and explanation of the beaker experiment over superfluid helium: So, according to this experiment, can anyone say what is the cause? I mean the superfluids are disconnected ...
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Lorentz force on superconductor vortices

I am reading a paper on superconductivity and in it it says that the vortices are subject to a Lorentz force given by $$\vec{F}_L=\frac{\Phi_0\vec{I} \times \vec{H}}{cH}$$ Here $\vec{F}_L$ is the ...
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Could some astronomical objects have superconducting properties?

The colder it is, the more efficient the superconductivity process works. And as we know, if there is no star nearby, space gets pretty cold. I do appreciate that many condensed, burnt out, stars ...
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Question about Meissner Effect video

In this video, what material is on top of the superconductor disk that keeping it cold? Is it just a circular chunk of dry ice? http://www.youtube.com/watch?v=Ws6AAhTw7RA I'm planning on recreating ...
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Is the first excited state of a superconducting qubit a stationary state?

A superconducting qubit is essentially an anharmonic oscillator with uneven spacings of the eigenstates. These states are eigenstates of the overall hamiltonian, which should mean that it is an energy ...
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Superconductors in a magnetic field — mixed phase

In my Stat Mech class we're learning about the phase transition between superconducting and non-superconducting metals in the presence of a magnetic field (Chapter 7, Kittel). I understand that the ...
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What is a d + id superconductor and why does it break time reversal symmetry?

There are a lot of publications dealing with d-wave and d + id superconductivity, but I found no satisfying answer what exactly makes a superconductor d + id and why they break time reversal symmetry. ...
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Topological superconductors: what is the role of spin-orbit coupling? Are there topological non-trivial states without spin-orbit?

Let's say I have a one-dimensional system with particle-hole symmetry and with broken time-reversal symmetry. As a consequence, the chiral symmetry is also broken in this case (the chiral symmetry ...
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Does a magnet floating over a superconductor slowly fall and take infinite time to stabilize?

The reasoning being that as the magnet moves towards the superconductor it induces an opposite magnetic field, until the latter rises sufficiently to equal the weight of the magnet. Except that looks ...
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Questions concerning BCS theory (particularly the “pairing Hamiltonian”)

I've been reading up about the BCS theory of superconductivity, and the treatments I've seen begin rather mysteriously with a Hamiltonian that (in the language of second quantization) looks ...
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Lifting capacity of superconductors

How does the strength of the magnetic field the superconductor is exposed to affect its ability to levitate/lock heavier objects? Or is there no relationship (for superconductors) between magnetic ...
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Mutual inductance versus self inductance of two parallel thin-film wires

I am considering the scenario of two long superconducting thin-film wires (thickness << width << length) running parallel to eachother. They carry a current density that is as usual peaked ...
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Is there net current through a Josephson junction at zero bias?

It is widely stated that when a Josephson junction is placed in a superconducting circuit, the cooper pairs can tunnel through and create a net current without a bias voltage. However, given that the ...
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Why is a transmon a charge qubit?

The classic charge qubit is the cooper pair box which is a capacitor in series with a Josephson junction. In my understanding, by changing the gate voltage at the capacitor, one can create a ...
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Does flux quantization require uniform pair density?

Consider a superconducting circuit with a "box-like 8" geometry like [|] (ie. two square loops which share one side of wire). Here we can have three different currents ($I_1=I_2+I_3$, see H. J. Fink ...
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How to compute the density of state from the Green function?

I'd like to plot the density of state (DOS) for a specific system, say an s-wave BCS superconductor, the Green function of which is ...
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can we have a phase transition from superconductor to the normal only by applying magnetic field?

for superconductors we have a phase transition diagram. according to that phase diagram in a temperature below Tc, we can only increase the applied magnetic field to make a superconductor a normal. ...
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Why is the quench temperature fluctuation not a concern for maglev trains?

I am having trouble discovering why temperature fluctuations and magnetic field fluctuations are not a stability concern for superconducting magnetic levitation trains. I am under the impression that ...
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Superconductivity in space [closed]

Do you think you could use the drastically reduced temperatures in space to create superconductivity on the outside of a ship, for power on the inside, preventing overheating, and a near constant ...
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Meissner effect and levitation

In a field less than critical field, decreasing the temperature below the critical temperature will eliminate the magnetic field inside a superconductor and increase the magnetic field around it. ...