Non-unitary triplet pairing in the centrosymmetric superconductor   LaNiGa$_2$
  Muon spin rotation and relaxation experiments on the centrosymmetric intermetallic superconductor LaNiGa$_2$ are reported. The appearance of spontaneous magnetic fields coincides with the onset of superconductivity, implying that the superconducting state breaks time reversal symmetry, similarly to non-centrosymmetric LaNiC$_2$. Only four triplet states are compatible with this observation, all of which are non-unitary triplets. This suggests that LaNiGa$_2$ is the centrosymmetric analogue of LaNiC$_2$. We argue that these materials are representatives of a new family of paramagnetic non-unitary superconductors. 
A. D. Hillier and J. Quintanilla and B. Mazidian and J. F. Annett and   R. Cywinski
cond-mat.supr-con cond-mat.str-el