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 non-centrosymmetric LaNiC2. Only four triplet states are compatible with this observation, all of which are non-unitary triplets. This suggests that LaNiGa2 is the centrosymmetric analogue of LaNiC2. We argue that these materials are representatives of a new family of paramagnetic non-unitary superconductors.
@article{arxiv.1206.5905,
title = {Non-unitary triplet pairing in the centrosymmetric superconductor LaNiGa$_2$},
author = {A. D. Hillier and J. Quintanilla and B. Mazidian and J. F. Annett and R. Cywinski},
journal= {arXiv preprint arXiv:1206.5905},
year = {2015}
}
Comments
Accepted in Phys. Rev. Lett. arXiv admin note: substantial text overlap with arXiv:0901.3153