Muon spin rotation and relaxation experiments on the centrosymmetric intermetallic superconductor LaNiGa2 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 noncentrosymmetric LaNiC2. Only four triplet states are compatible with this observation, all of which are nonunitary triplets. This suggests that LaNiGa2 is the centrosymmetric analogue of LaNiC2.We argue that these materials are representatives of a new family of paramagnetic nonunitary superconductors.
|Translated title of the contribution
|Evidence for non-unitary and time-reversal symmetry breaking in the centrosymmetric superconductor LaNiGa2
|Number of pages
|Physical Review Letters
|Early online date
|27 Aug 2012
|Published - 31 Aug 2012