Constraints on the superconducting order parameter in Sr2RuO4 from oxygen-17 nuclear magnetic resonance

Nature, Published online: 23 September 2019; doi:10.1038/s41586-019-1596-2

17O nuclear magnetic resonance measurements on Sr2RuO4 reveal a drop of the Knight shift in the superconducting state, contradicting previous work and imposing tight constraints on the order parameter symmetry of the system.