Out of curiosity, does anyone know what it is that change on an physical level for electrons to move without resistance in an superconductivity material? What is it that change when it happens and the material become superconductive and why?
In low-temperature (liquid helium) superconductors electrons start slightly sticking to each other. This makes their energy spectrum quantized (I mean, even more than usual), so to transfer any energy to electrons it has to be in a large enough chunk to kick them apart.
And cold atoms don't have enough thermal energy to do that, so there's no energy transfer between atoms and electron pairs.
In high-temperature superconductors (liquid nitrogen) something similar happens, but the exact mechanism is still unknown.
