An international team led by the Autonomous University of Madrid (UAM), in collaboration with the Niels Bohr Institute (NBI), the Donostia International Physics Centre (DIPC), the University of Valencia and centres in Argentina and the Netherlands, has demonstrated that minuscule amounts of magnetic impurities combined with structural disorder are sufficient to destroy the energy gap in a conventional superconductor. The finding, published in Advanced Materials, challenges some classical predictions about the extent to which superconductivity tolerates imperfections, and could have implications for the design of future quantum devices.
