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 a magnetic field be expelled over long arbitrary distances through a super conductor? [on hold]

I'm not a physiscist but i have a creative concept I wish to make into a environmental commercial before my Interactive Feature Film. Apologies, if it sounds like I have no idea what I'm talking ...
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The requirements for superconductivity

Which properties are sufficient evidence for a material to be not superconducting? I am looking for a set of statements like If the material is semiconducting, it is not superconducting Edit: I ...
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Question about superconductivity

A long cylinder of radius $R$ is made from two different material. Its radius $r<r_0$ $(r_0<R)$ part is a material with superconducting transition temperature $T_1$, and its $r_0<r<R$ ...
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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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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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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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Superconducting electromagnets?

Is it true that superconducting electromagnets don't need any power? So... energy to created a magnetic field via a superconductor would be zero? Since resistance is zero, does that also mean that ...
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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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Superconductivity in graphene with spin orbital coupling, is it proper to let the order parameter on two sub-lattice equal?

I am reading this article: Edge superconducting correlation in the attractive-U Kane-Mele-Hubbard model. Considering just the first part of the article, where a negative-U Hubbard model with the ...
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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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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 London penetration depth independent from the magnetic field strength in superconductors?

in superconductivity, type I, we say that the penetration depth of the magnetic field is independent of the magnetic field strength applied to the sample... i just want to know why? you know, the ...
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How do superconducting materials float in magnetic field?

The movie Avatar got me interested in the subject, but so far I only found sophisticated articles loaded with unfamiliar words. Is there a simple way to explain how magnetic field affects ...
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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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Is current in superconductors infinite? If they have 0 resistance then I (V/R) should be infinite? [duplicate]

I learned many years ago that according to Ohm's law, current is equal to voltage divided by resistance. Now if superconductors have zero resistance then the current should be infinite. Moreover the ...
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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. ...
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How can Ohm's law be correct if superconductors have 0 resistivity?

Ohm's law states that the relationship between current ( I ) voltage ( V ) and resistance ( R ) is $$I = \frac{V}{R}$$ However superconductors cause the resistance of a material to go to zero, and ...
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what experiments can be used to distinguish between s-wave and d-wave superconductivity?

What are some experiments which be used to distinguish between s-wave and d-wave superconductivity?
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173 views

Analogies between Fraunhofer diffraction and Josephson junctions

There are several analogies between diffraction patterns and Josephson junctions, especially between a double slit experiment and two Josephson junctions in a superconducting ring (like this): Both ...
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The wavefunction of the superconductor A consists of two parts: B and C

In reading this article, I come across this paragraph: The pink marked place is where I can't understand, why can we use direct product of the former but not the later? This is may be a basic ...
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What kind of free energy do we use for a superconductor in a magnetic field?

My reasoning is as follows (using Gaussian units): Start from the second law: $$dU=TdS+dW,$$ where $dW$ is the work done by the magnetic field. To derive $dW$, we consider a solenoid with current ...
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Does the Meissner effect only effect magnetic fields?

I find this effect very interesting and was wondering what tests have been performed to check its effects on other fields? Also a side question related to this effect, can it trap a magnetic field. ...
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How much charge per unit time passes with the Josephson current

I wonder how does the simple defintion of a current $I = \frac{dQ}{dt}$, i.e. charge per unit time which passes through some area, is applied to the Josephson effect. If I have a Josephson junction ...
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Why does the superconductivity hamiltonian have a µ term, while the superfluid does not?

In every discussion of SC and SF that I read (e.g. Simons), the SC Hamiltonian (BCS) has a $\epsilon_k - \mu$ in the kinetic part of the Hamiltonian, while the SF Hamiltonian has just a $\epsilon_k + ...
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Feshbach resonance in simple terms

I was reading up Feshbach resonances in cold atoms and I was unable to grasp the concept. I will tell you what I have understood. We consider two body scattering processes elastic as well as ...
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How is Meissner effect explained by BCS theory?

Someone says we can derive the GL equations from BCS theory, which can explain Meissner effect, but I want a more clear physical picture of this phenomena.
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Why talking BCS Hamiltonian doesn't conserve particle number?

The BCS Hamiltonian reads: $$H_{BCS}=\sum_{k\sigma}\epsilon_k c_{k\sigma}^\dagger c_{k\sigma}-\Delta^*\sum_k c_{k\uparrow}^\dagger c_{-k\downarrow}^\dagger+h.c.$$ The particle number operator reads: ...
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What happens to magnetic $B$-field in a superconductor in the Bean model?

In the Bean model, as we start applying a magnetic field $H$ in the plane of a slab, the $B$-field inside the superconductor decreases linearly from each side, and at a sufficiently high field $H^{*}$ ...
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Induced-EMF and Lorentz force,

If a superconductor was placed inside a magnetic field(below critical magnetic field) can it experience the Lorentz force = $IL\times$ $B$? Also, if a superconductor moving inside a magnetic field, ...
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31 views

Classification of Bogoliubov de Gennes Hamiltonians

This question refers to the paper Nonstandard symmetry classes in mesoscopic normal-superconducting hybrid structures by Altland and Zirnbauer. In the paper the authors give a classification of ...
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Is the superconducting current made up of Cooper pairs?

Inside the superconductor it should be $\mu_0\mathbf{j} = \mathbf{\nabla} \times \mathbf{B} = 0$, since B is 0 due to the Messner effect. This means that the current is carried by the surface. But ...
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Angle-resolved photoemission spectral (ARPES) function from band Hamiltonian

I am trying to derive spectral function for a band Hamiltonian. I am using http://arxiv.org/abs/cond-mat/0306084 as a prototype reference. I do not understand how the coherence factors $u_k$ and $v_k$ ...
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Ampère's law and superconductors

I have been reading about superconductors and emerge me a inquietude about the explanation of existence of currents inside the superconductor while their magnetic field (inside too) is zero. Based in ...
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What makes a superconductor topological?

I have read a fair bit about topological insulators and proximity induced Majorana bound states when placing a superconductor in proximity to a topological insulator. I've also read a bit about ...
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Isotope effect in BCS Theory

The BCS theory for supercondictivity says that the effect of variation of lattice ion mass (M) and its effect on transition temperature is given as $T_{c} \space\alpha\space M^{-\beta}$ . The ...
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BCS-BEC crossover

It would be really helpful if somebody could describe what does one mean by a BEC-BCS Crossover. I was going through articles available on the topic, but I was unable to grasp the gist of the topic.
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Bogoliubov quasiparticle current

How to calculate the quasiparticle current density starting from bogoliubov - de gennes equation: $$\left( \begin{array}{cc}H_{0} - E_{F} & -i\sigma_{y}\Delta \\ i\sigma_{y}\Delta^{*} & E_{F} ...
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Does disorder reduce superconducting transition temperatures?

What is the main reason through which disorder can reduce superconducting transition temperatures in d-wave supercondutors? Does this typically occur when the electron mean free path becomes smaller ...
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When was the first time that superconducting quasiparticles were called Majorana fermions?

Since a number of years, the field of superconductivity has a growing obsession with Majorana fermions. I wonder how far back we can go: When was the first time that superconducting quasiparticles ...
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Magnets quantum locking/levitating [duplicate]

How does cooling a magnet allow it to quantum lock/levitate? I have seen it in videos but do not know how it works.
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How to derive electron number equation of Bogoliubov Hamiltonian using thermodynamic relations.

My question arise from this article: Edge superconducting correlation in the attractive-U Kane-Mele-Hubbard model. I will describe my question in detail so that you might not need to look into that ...
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Alternative to Cooper pairing in superconductivity

BCS theory, in which electrons form Cooper pairs, has been successful in explaining conventional superconductivity. Physicists have adopted similar pairing mechanism in an attempt to explain ...
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On the Bogoliubov transformation in the BCS

I have a question regarding the diagonalization of the BCS-Hamiltonian using the Bogoliubov-DeGennes-transformation. I hope someone can help me, so I start with the following Hamiltonian, it is ...
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Seiberg-Witten theory and Superconductivity

There seems to have some (deep) relation between Seiberg-Witten theory and superconductivity. e.g. this Witten paper. Q: Could someone introduce the relations between the twos both physically in ...
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Intuitive explanation for the existence of an energy gap in superconductors

In 2012 there was a nice answer explaining basic superconductivity. It ends with the sentence: The trouble is you're now going to ask for an intuitive description of why the electron correlations ...
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Destroying currents in superconducting rings by vortex tunneling

Consider a superconducting metal ring in which there is a persisting current $I$. I am interested in the failure of this current to remain "persisting" in the ring, although this will occur at ...
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What observables are indicative of BCS Cooper pair condensation?

What observables are indicative of BCS Cooper pair condensation? "Thought" experiments and "numerical" experiments are allowed. This question is motivated by the question Has BCS Cooper pair ...
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Precisely speaking, does photon become massive or the phonon become massive, due to Higgs mechanism in superconductor?

Consider the low-energy field theories of superfluids and superconductors. In superfluids, the spontaneous breaking of the order parameter's phase creates phonons as the massless Goldstone ...