Superconductivity in the nonsymmorphic line-nodal compound CaSb₂

We found superconductivity in CaSb₂ with the transition onset of 1.8 K by means of electrical-resistivity, magnetic-susceptibility, and specific-heat measurements [1]. Zero resistance was observed below 1.2 K, and the superconducting volume fraction at 0 K was estimated to be 65% from specific heat. This material crystallizes in a nonsymmorphic structure and is predicted to have multiple Dirac nodal lines in the bulk electronic band structure protected by crystalline symmetry even in the presence of spin-orbit coupling. In this presentation, we will briefly introduce the band structure of CaSb₂ and then show experimental results evidencing its bulk superconductivity.
[1] A. Ikeda et al., Phys. Rev. Mater. 4, 041801(R) (2020).