Superconducting and normal state properties of the noncentrosymmetric superconductor NbOs2 investigated by muon spin relaxation and rotation

Abstract

Noncentrosymmetric superconductors with α-manganese structure has attracted much attention recently, after the discovery of time-reversal symmetry breaking in all the members of the Re6X (X=Ti, Hf, Zr) family. Similar to Re6X, NbOs2 also adopts α−Mn structure and is found to be superconducting with critical temperature Tc≃2.7 K. The results of the resistivity, magnetization, specific heat, and muon spin relaxation/rotation measurements show that NbOs2 is a weakly coupled type-II superconductor. Interestingly, the zero-field muon experiments indicate that the time-reversal symmetry is preserved in the superconducting state. The low-temperature transverse-field muon measurements and the specific-heat data evidence a conventional isotropic fully gapped superconductivity. However, the calculated electronic properties in this material show that the NbOs2 is positioned close to the band of unconventionality of the Uemura plot, indicating that NbOs2 potentially borders an unconventional superconducting ground state.

Source-reported materials — not catalogue approval

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