A New Superconductor - Technology Review: Researchers are also hoping that iron arsenides will help unlock the mystery of how high-temperature superconductors work. That will be key for designing materials with even higher critical temperatures. In superconductors that work at very low temperatures, such as niobium and lead, electrons form pairs below the critical temperature. Atoms or defects in the crystal do not have the energy needed to break the pair and deflect the electrons. So the electron pair zips around the material unimpeded, giving rise to superconductivity. But this pairing theory does not hold for high-temperature copper-oxygen materials.
In their Nature paper, Chien and his colleagues show evidence suggesting that the pairing theory might hold for the iron arsenide superconductors. "The pairing of electrons is the soul of the superconductor," Chien says. "If the new materials follow the [pairing] theory, then . . . we will be able to understand the materials a little bit easier."