Room temperature superconductor?:

Originally posted by sonhouse
Discounting magnetic field effects, what is the difference?

Bear in mind that in the following I'll be mixing classical and quantum descriptions:

Classicaly speaking the resistivity of a material is related to the existence of defects on its atomic structure. The more defects the bigger the resistivity. The less defects the littler the resistivity. Classically speaking a perfect conductor is a material with no defects on its crystalline structure (hence zero resistivity)

Superconductivity is a quantum phenomena and it entails a new state of matter. The material still has defects on its crystalline structure (hence classically it should display a non null resistivity) but due to quantum effects it shows no resistivity on the passage of electric current.

Thus the root cause of zero resistivity is one other difference.

Originally posted by adam warlock
Bear in mind that in the following I'll be mixing classical and quantum descriptions:

Classicaly speaking the resistivity of a material is related to the existence of defects on its atomic structure. The more defects the bigger the resistivity. The less defects the littler the resistivity. Classically speaking a perfect conductor is a material with n ...[text shortened]... passage of electric current.

Thus the root cause of zero resistivity is one other difference.

You could liken it to a beam of electrons. If the electrons are guided perfectly down the vacuum chamber or say, on the surface of the moon, and collected perfectly, it could be said the electron beam exhibited zero resistance too.

Of course the real world would sneak in there and steal electrons by several means and it would be in effect a non-zero resistance.

Here is a small bit of progress in narrowing down the cause of high-temperature superconductivity: the theory that it is due entirely to some kind of "electron-phonon coupling" has finally been ruled out:

http://phys.org/news/2013-11-x-rays-reveal-feature-high-temperature-superconductivity.html

This is only small progress but, still, this is now one less place for the mystery of what causes high-temperature superconductivity to hide and thus one step closer for it to run out of places to hide.