Evidence for multimodal superfluidity of neutrons

We present theoretical and experimental evidence for a new phase of matter in neutron-rich systems that we call multimodal superfluidity. Using ab initio lattice calculations, we show that the condensate features both s-wave pairs and quartets formed by the binding of two such pairs. We also present experimental data showing that quartet gaps are present in neutron-rich nuclei. We discuss the implications of multimodal superfluidity and higher-order condensates for condensed matter and ultracold atomic and molecular systems as well as the superfluid properties of neutron star crusts.