Superconducting ground state of the nonsymmorphic superconducting compound Zr2Ir

The nonsymmorphic Zr2Ir alloy is a possible topological semimetal candidate material and as such may be part of an exotic class of superconductors. Zr2Ir is a superconductor with a transition temperature of 7.4 K with critical fields of 19.6(3) mT and 3.79(3) T, as determined by heat capacity and magnetization. Zero-field muon spin relaxation measurements show that time-reversal symmetry is preserved in these materials. The specific heat and transverse field muon spin rotation measurements rule out any possibility to have a nodal or anisotropic superconducting gap, revealing a conventional s-wave nature in the superconducting ground state. Therefore this system is found to be a conventional nonsymmorphic superconductor, with time-reversal symmetry being preserved and an isotropic superconducting gap.