ReBCO tape is interesting stuff. It's a high-temperature superconductor (high-temperature meaning still really cold, but you don't need liquid helium to get th

ReBCO tape is interesting stuff. It's a high-temperature superconductor (high-temperature meaning still really cold, but you don't need liquid helium to get there) that can carry a lot of current before it stops being superconducting. It's being used in new tokomak fusion reactor designs, like SPARC. https://en.wikipedia.org/wiki/Rare-earth_barium_copper_oxide https://en.wikipedia.org/wiki/Rare-earth_barium_copper_oxide