Superconducting Properties of Noncentrosymmetric Superconductor LaPt3Si Studied by Muon Spin Spectroscopy

The superconducting properties of the noncentrosymmetric superconductor LaPt3Si were investigated by mu SR spectroscopy. Within experimental accuracy, spontaneous internal fields were not observed in the superconducting phase by zero-field mu SR experiments. Transverse-field mu SR experiments revealed the coexistence of the intermediate and mixed states in the superconducting phase, which are characteristic features of type-I and type-II superconductors, respectively. We found that the observed anomalous field distribution is consistent with the results of a recent numerical calculation for type-1.5 superconductors.