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arXiv · 2302.08075

Nodeless superconductivity in the noncentrosymmetric ThIrSi compound

D. Tay·T. Shang·Priscila F. S. Rosa·F. B. Santos·J. D. Thompson·Z. Fisk·H. -R. Ott·T. Shiroka
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Abstract

The ThIrSi superconductor, with $T_c = 6.5$ K, is expected to show unusual features in view of its noncentrosymmetric structure and the presence of heavy elements featuring a sizable spin-orbit coupling. Here, we report a comprehensive study of its electronic properties by means of local-probe techniques: muon-spin rotation and relaxation ({\textmu}SR) and nuclear magnetic resonance (NMR). Both the superfluid density $\rho_\mathrm{sc}(T)$ (determined via transverse-field {\textmu}SR) and the spin-lattice relaxation rate $T_1^{-1}(T)$ (determined via NMR) suggest a nodeless superconductivity. Furthermore, the absence of spontaneous magnetic fields below $T_c$, as evinced from zero-field {\textmu}SR measurements, indicates a preserved time-reversal symmetry in the superconducting state of ThIrSi. Temperature-dependent upper critical fields as well as field-dependent superconducting muon-spin relaxations suggest the presence of multiple superconducting gaps in ThIrSi.

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D. Tay, T. Shang, Priscila F. S. Rosa, F. B. Santos, J. D. Thompson, Z. Fisk, H. -R. Ott, T. Shiroka. 2023-02-16. Nodeless superconductivity in the noncentrosymmetric ThIrSi compound. https://doi.org/10.1103/physrevb.107.064507

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