Recent content by DrDu

I think that a wealth of this kind of experiments has been performed and published as the understanding of the breakdown of superconductivity in coils due to fluctuations of the field or the temperature is of vital technological importance. Tinkham also contains references.

I had a look at your draft. In steady state, there will be an influx of Cooper pairs into the non-SC chamber and a reflux of electrons into the SC wire. Already in the wire, the electrons will recombine into Cooper pairs. Besides the small current of opposite direction carried by the Cooper...

The pairs are in a condensate and the whole condensate has to be accelerated. The acceleration of the condensate is due to the electric field generated by the decaying normal current. You made me look up some basics isn "Michael Tihnkham, Introduction to Superconductivity", namely section 2.5 on...

This is a thermodynamical argument, not an argument about violation of conservation of momentum. So I think we can agree on that there is no violation of conservation of (angular) momentum. Considering now thermodynamics, you seem to claim that the reduction of superconductive charge carrier...

This is a thermodynamical argument, not an argument about violation of conservation of momentum. So I think we can agree on that there is no violation of conservation of (angular) momentum. Considering now thermodynamics, you seem to claim that the reduction of superconductive charge carrier...

When talking about London forces, you always need at least two atoms. Their dipole dipole interaction involves the product of the dipole moment operators d1 and d2 of the two atoms. While the expectation value of each of these operator vanishes, that of their product is non-vanishing, given that...

The collision of the normal conducting electrons with the lattice preserves (angular) momentum. It is first carried by the electrons, afterwards by the lattice. Likewise, an electric field changes the momentum of the electrons and the lattice by a degree of like absolute value but opposite sign...

Of course the normal conducting electrons will slow down due to collisions with the lattice atoms. Normal resistivity. Where is the contradiction?

I really think there is a very small transient decrease of supercurrent, if you suddenly decrease the superconducting density by changing the temperature. The penetration depth of the magnetic field and of the current density is proportional to 1/sqrt(n_s). A decrease in n_s leads to an increase...

Found this interesting article: https://arxiv.org/pdf/1609.08451

In principle, this is the Einstein - de Haas effect. The electronic sub-system condenses into a broken symmetry state with non-vanishing angular momentum and the complete system starts to rotate due to angular momentum conservation. PS: Obviously, I am not the first one to remark this...

There is no momentum conservation for the electrons alone. Momentum can always be taken up from or given to the lattice.

Breaking a pair reduces the magnetic field which leads to an electric field which speeds up the other Cooper pairs which increase the magnetic field. In the end, the magnetic field stays constant and the cooper pairs speed up so as to keep current constant, as claimed by the London equations

For me it works fine. For legal reasons I find it problematic to upload papers I do not own.

I looked for bader's electron localisation function and NaCl and found the following paper which seems to support the classical picture: https://www.lct.jussieu.fr/pagesperso/savin/papers/forbader-nacl/forbader-nacl.pdf