University of Groningen physicists, and colleagues from Nijmegen and Hong Kong, have induced superconductivity in a monolayer of tungsten disulfide. By using an increasing electric field, they were able to show how the material turns from an insulator into a superconductor and then back into a re-entrant insulator again. Their results show the typical dome-shaped superconducting phase, and finally provide an explanation for this phenomenon. The results were published in Proceedings of the National Academy of Sciences on 19 March.