Where in this thread have I, or ben, or Zig, said that any of the standard superconductivity experiments are impossible?
All three of you have argued consistently that if you have two wires connected to a superconductor with a source voltage V across the wires and sends through a charge Q, the charge will come out with a higher energy QV on the other side. Go back on your postings and read it yourself. This means that you are arguing that the actual superconductivity experiments which prove that the charge goes in and comes out with the same energy must be wrong!
You're communicating on this forum with (at least) three people who are very knowledgeable on physics, fairly patient, and willing to give you the benefit of the doubt.
Maybe you are knowledgeable on the physics you are doing, but if you claim that a charge Q being injected into a superconductor by a source voltage V will appear on the other side with an energy QV higher, then you obviously are not knowledgeable on superconduction.
And yet, at least so far, you have failed completely to explain to us what seems like your most basic and simple claim (that the energy emitted by a charge q going though a Josephson junction with voltage V should be 2qV). As we both said earlier - if we can't come to an agreement on that, there's no point in discussing anything further.
Well if you do not
want to accept the experimental fact that a charge q moving through a superconductor cannot be accelerated to gain energy qV
main, where V
main is the source voltage injecting the charge (since there is no electric-field within the superconductor): And if you do not
want to accept the experimental fact that when you place a voltage over a Josephson junction it shifts the energy levels on opposite sides of the junction by qV: And if you do not want to accept the fact that when the charge carrier now moves through the junction it must also be accelerated to gain energy qV: And if you do not want to add that 1+1=2: i.e. that the shift in energy levels plus the increase in energy owing to the acceleration come to 2qV. Then you just do not want to accept the experimental facts and the simple fact that when a charge moves through a voltage that it can "see" it will be accelerated to gain energy qV.
If you would answer my (very simple) question - a question about what is one of the most standard experiments in the physics of Josephson junctions, found in fact in every textbook - I think I could quickly show you that you are mistaken, which is why I'm focussing on it.
I did answer it in detail.
You told me that a voltage source that "injects charge carriers" would create a voltage V across the junction,
You see you do not read what I am writing: It is just the other way around: Look at the simple IV characteristics of a Josephson junction in any elementary text book.
while one that doesn't would create no voltage.
Again the other way around.
You never responded to my question about what type of voltage source a chemical battery is (or what more information you need than "chemical battery" to decide), or what type of source a standard lab powered voltage source is, or provided the reference you said exists.
Because it is obviously irrelevant whether it is a chemical source or a DC source plugged into a socket which injects the charge carriers; and irrelevant what type of source is used to place an extra field over the junction without injecting charge carriers.
I do not want to insult you but your arguments do not display any knowledge about the experimental results which had been measured, and confirmed time and again, for Josephson junctions.
But even without that - if you accept that this situation
V ---|--- 0
can exist at all ever, we can go on.
Is the voltage V injecting charge which moves through the superconductor SIS? Then the situation is 0----I---0; since the voltage is cancelled everywhere. Is the voltage V applied by two capacitor plates across the SIS so that no charge-carriers are injected, then it is V---I---0 across the insulating junction.
What's the minimum amount of work required to move a charge q against a voltage V?
If the voltage is placed over a normal conductor, the minimum amount of work is qV. If it injects the charge q into the superconductor, the minimum amount of work is zero.
What's the maximum amount of work that can be extracted after a charge q moves with a voltage (i.e gains energy) V?
In a normal conductor with a voltage V across it, it is qV. For a superconductor where V injects a charge q, the maximum amount of work is still zero. If you place an extra voltage V over the Josephson junction, the energy levels on opposite sides of the junction is shifted by qV, and in addition the charge, when moving through the junction, is accelerated to gain a further amount of energy qV. Thus to become part of the superconducting phase on the other side, after it has moved through the junction, it has to radiate away 2qV.