Yifan Jiang

The crystal of perovskite iridate SrIrO₃ resembles a row of soldiers, where each iridium carries a magnetic moment. When some of the iridium 'soldiers' are replaced by tin, which has no magnetic moment, the row thins out.

A graphene sheet is a one-atom-thick grid of carbon atoms. Stacking several such sheets with a specific twist yields a material with unusual properties: it can be a magnet or a superconductor depending on how you poke it. The trouble is that in natural graphite, such 'properly twisted' layers are rare, and growing them artificially is tricky.