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arXiv · 1811.01181

Nodeless superconductivity in the noncentrosymmetric Mo$_3$Rh$_2$N superconductor: a $\mu$SR study

T. Shang·Wesen Wei·C. Baines·J. L. Zhang·H. F. Du·M. Medarde·M. Shi·J. Mesot·T. Shiroka
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Abstract

The noncentrosymmetric superconductor Mo$_3$Rh$_2$N, with $T_c = 4.6$ K, adopts a $\beta$-Mn-type structure (space group $P$4$_1$32), similar to that of Mo$_3$Al$_2$C. Its bulk superconductivity was characterized by magnetization and heat-capacity measurements, while its microscopic electronic properties were investigated by means of muon-spin rotation and relaxation ($\mu$SR). The low-temperature superfluid density, measured via transverse-field (TF)-$\mu$SR, evidences a fully-gapped superconducting state with $\Delta_0 = 1.73 k_\mathrm{B}T_c$, very close to 1.76 $k_\mathrm{B}T_c$ - the BCS gap value for the weak coupling case, and a magnetic penetration depth $\lambda_0 = 586$ nm. The absence of spontaneous magnetic fields below the onset of superconductivity, as determined by zero-field (ZF)-$\mu$SR measurements, hints at a preserved time-reversal symmetry in the superconducting state. Both TF-and ZF-$\mu$SR results evidence a spin-singlet pairing in Mo$_3$Rh$_2$N.

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T. Shang, Wesen Wei, C. Baines, J. L. Zhang, H. F. Du, M. Medarde, M. Shi, J. Mesot, T. Shiroka. 2018-11-03. Nodeless superconductivity in the noncentrosymmetric Mo$_3$Rh$_2$N superconductor: a $\mu$SR study. https://doi.org/10.1103/physrevb.98.180504

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