The following quote shows that there is plenty of scope for super-conduction by "cold" positrons.
================================ "The BCS theory only applies in metals with free electrons that can be paired up, not in ceramic insulators. But, the claim was made that these ceramics could be made superconducting at much higher temperature than the highest known metallic superconductor... To this day, as far as I know, there is no satisfactory explanation of the effect. Even John Bardeen himself was unable to come up with an explanation. But it works, and the alloy combination has been modified to tweak the temperature up to nearly 100 K. I expect that some day someone will hit on a way to explain the effect, but the lack of a theory has certainly not been a restraint on people utilizing the effect. There are commercially available kits to demonstrate high-Tc superconductivity in probably every physics department in the country." ===================================== Frank Grimer
