The crystal that breaks time — politely

Anshu Kataria and her team at IISER Bhopal grew single crystals of YbSb2, cooled them to near absolute zero, and watched tiny magnetic fields appear out of nowhere as the material went superconducting. That's time-reversal symmetry breaking — the hallmark of unconventional superconductivity — in a type I superconductor, where nobody had ever seen it. Their calculations say the state may host Majorana modes, the exotic particles quantum computers dream about. Published in Physical Review Letters.