Introducing a new noncentrosymmetric superconductor: Zr₃Ir

An intrinsic momentum dependent antisymmetric spin-orbit coupling (ASOC) in noncentrosymmetric (NCS) systems arising due to lack of inversion center in the crystal structure gives way to numerous unusual superconducting properties [1]. The Fermi surface in these systems becomes nondegenerate in the presence of spin-orbit coupling, giving a plausibility to form an admixed superconducting order parameter. This breaks the conventional notion of even parity spin-singlet and odd parity spin-triplet order parameter, leading to the high upper critical field, anisotropic superconducting gap, and time-reversal symmetry breaking [1]. We report a new NCS compound Zr₃Ir, crystallizes in a tetragonal α-V3S structure. The magnetization, specific heat, and muon spin rotation confirm s-wave superconductivity, having a transition temperature Tc = 2.3 K. Muon spin relaxation confirms the preservation of time reversal symmetry in the superconducting ground state [2].

References
1. M. Smidman, et al., Rep. Prog. Phys. 80, 036501 (2017).
2. Sajilesh K. P., et al., Phys. Rev. M. 3, 104802 (2019).