From what we learned in Chemistry in college, if I remember correctly, superconductivity at extremely low temperatures works like this:

At incredibly low temperature electron movement slows down to nil as you approach absulte zero. This causes electron latices to form in symmetry and makes it easier for them to carry a charge. More efficiently, I guess, not necessarily more easily.

Thus at lower temperature states, it is easier to conduct electricity through highly conductive metals (gold, platinum, etc.), because the electrons aren't moving as much.


However, since it's been ten years since I sat in a classroom, this could all be pulled right out of my ass.