The presence of spin-orbit (SO) interaction in a noncentrosymmetric superconductor, La2 C3 (Tc ≃ 11 K) is demonstrated by muon spin rotation (μSR) in its normal state, where μSR spectra exhibit field-induced weak depolarization due to van Vleck-like local susceptibility. In the mixed state, muon spin relaxation due to inhomogeneity of internal field (σv) exhibits a field dependence that is characterized by a kink, where σv (and hence the superfluid density) is more strongly reduced at lower fields. This is perfectly in line with the presence of a secondary energy gap previously inferred from the temperature dependence of σv, and also consistent with the possible influence of asymmetric deformation of the Fermi surface due to the SO interaction.
- Quasiparticle excitation
- Spin-orbit interaction
ASJC Scopus subject areas
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering