
Graphene’s sleeping superconductivity awakens - jonbaer
https://www.cam.ac.uk/research/news/graphenes-sleeping-superconductivity-awakens
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jessriedel
The article broke the DOI number by dropping the decimal. It's
10.1038/ncomms14024 . You can get the PDF from the journal webpage since it's
open access.
[http://www.nature.com/articles/ncomms14024](http://www.nature.com/articles/ncomms14024)

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ythn
I don't get how superconductors fit in with V = IR. Assuming that
superconductors literally have zero resistance, doesn't that imply there will
always be zero voltage on the line as well? And without voltage, how can you
push current through?

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pjc50
Ohm's law is like Newtonian gravity: an approximation that ignores quantum
effects. V=IR is not precise; across every resistor there is _also_ a quantity
of Johnson-Nyquist noise. This nearly always doesn't matter except when
building high-precision instrumentation amplifiers.

(What I don't know: are superconductors also free of thermal noise? That could
have useful properties of its own..)

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simcop2387
It honk that they're supposed to be free of that thermal noise because of the
way the magnetic and electric fields work to have zero resistance (the whole
thing would collapse if they did have thermal noise) but I don't know that
I've seen anything studying it either. I suppose it might not be studied or
characterized yet because of the fact that so many superconductors have
required temperatures cold enough that thermal noise would be nearly
impossible to measure in normal materials let alone something with no
resistance otherwise.

