Fermi Surface and Superconducting Properties of Non-centrosymmetric LaNiC2

Abstract

We succeeded in growing single crystals of LaNiC 2 with the non-centrosymmetric orthorhombic structure by the Czochralski method, and measured the electrical resistivity, de Haas–van Alphen effect, and specific heat to clarify the Fermi surface and superconducting properties. This compound has been studied from a viewpoint of the triplet superconducting pairing state. In the present experiment, we observed an ellipsoidal Fermi surface and a multiply-connected-pillar Fermi surface, which are split into two Fermi surfaces, reflecting the antisymmetric spin–orbit interaction based on the non-centrosymmetric crystal structure. The two ellipsoidal Fermi surfaces are split by 230 K, for example. The anisotropy of electrical resistivity and upper critical field H c2 in superconductivity are not large for three principal directions. From the low-temperature specific heat measurement, superconductivity in LaNiC 2 is explained by the framework of the BCS-superconductivity, contrary to the above arguments. The upper...