Pristine iron telluride is a superconductor, with the natural material’s superconductivity suppressed by excess iron in the crystal lattice, researchers in the US have shown. This resolves a long-standing puzzle about why, when other materials with similar structures showed superconductivity at low temperatures, iron telluride had always retained an antiferromagnetic order. The results provide a secure platform for further exploration of iron-based superconductivity, and could open the door to the study of interesting physics such as potential topological superconductivity in iron telluride itself. Much like the cuprates, iron-based superconductors such as chalcogenides like iron selenide often exhibit complex phase diagrams in which antiferromagnetic ground states compete with superconducting ones. Although tellurium sits directly underneath selenium in the periodic table, superconductivity has never been observed in pure iron telluride.…