Noncentrosymmetric superconductors Li 2Pd 3B and Li 2Pt 3B are studied by high-resolution photoemission spectroscopy. The valence band spectra of Li 2Pd 3B and Li 2Pt 3B are well explained by firstprinciples band calculations. The sub-meV photoemission result shows that the size of the superconducting gap of Li 2Pd 3B is about 1.1 meV at 5.4K with a reduced gap value (2Δ0=ξ BT c) of about 4.5, which is greater than the Bardeen-Cooper-Schrieffer (BCS) value of 3.52. The obtained superconducting gap can be explained more clearly with an s-wave superconducting gap than with p- and d-wave superconducting gaps. This result indicates that Li 2Pd 3B is a conventional strong-coupling superconductor.
- High-resolution photoemission spectroscopy
- Noncentrosymmetric superconductor
- Superconducting gap
ASJC Scopus subject areas
- Physics and Astronomy(all)