Super fluids and superconductors at the molecular level

[Josiah]

Hi I was wondering what happens to a super conductor at the molecular level? Why is there no resistance when electricity passes through it?

 

[Demystifier]

The conducting electrons interact with lattice atoms. It turns out that the lowest energy state of such interactions realizes when electrons form pairs (so called Cooper pairs) which effectively behave as integer spin bosons, which then undergo Bose-Einstein condensation so that all Cooper pairs together behave as a single superfluid. For more details google "BCS theory". I like the presentation in the book J.F. Annett, Superconductivity, Superfluids and Condensates.