Spin-singlet superconductivity with a full gap in locally non-centrosymmetric SrPtAs

Abstract

We report ${}^{195}$Pt-NMR and ${}^{75}$As-NQR measurements for the locally non-centrosymmetric superconductor SrPtAs where the As-Pt layer breaks inversion symmetry while globally the compound is centrosymmetric. The nuclear spin lattice relaxation rate $1/T_1$ shows a well-defined coherence peak below $T_c$ and decreases exponentially at low temperatures. The spin susceptibility measured by the Knight shift also decreases below $T_c$ down to $T<T_c/6$. These data together with the penetration depth obtained from the NMR spectra can be consistently explained by assuming a spin-singlet superconducting state with a full gap. Our results suggest that the spin-orbit coupling due to the local inversion-breaking is not large enough to bring about an exotic superconducting state, or the inter-layer hopping interaction is larger than the spin-orbit coupling.

10 pages, 6 figures. Accepted in Phys. Rev. B (Rapid Commun.)

References in corpus (6)

• Spin Triplet Superconducting State due to Broken Inversion Symmetry in Li_2Pt_3B
• Superconductivity in the Honeycomb-Lattice Pnictide SrPtAs
• Possible pairing symmetries in SrPtAs with a local lack of inversion center
• Abrupt enhancement of non-centrosymmetry and appearance of the spin-triplet superconducting state in Li_2(Pd_{1-x}Pt_{x})_3B beyond x=0.8
• Nodal $d+id$ pairing and topological phases on the triangular lattice: unconventional superconducting state of Na${}_x$CoO${}_2\cdot y$H${}_2$O
• Superconducting state in the non-centrosymmetric Mg_{9.3}Ir_{19}B_{16.7} and Mg_{10.5}Ir_{19}B_{17.1} revealed by NMR

Cited by in corpus (10)

• Superconductivity in Noncentrosymmetric Iridium Silicide Li2IrSi3
• Full-gap superconductivity in non-centrosymmetric Re${}_6$Zr, Re${}_{27}$Zr${}_5$ and Re${}_{24}$Zr${}_5$
• Possibility of chiral $d$-wave state in the hexagonal pnictide superconductor SrPtAs
• Surface magnetism in a chiral d-wave superconductor with hexagonal symmetry
• Superconductivity in MgPtSi: An orthorhombic variant of MgB2
• Study on Susceptibilities of Superconductors BaPtSb and BaPtAs with Honeycomb Structure
• Anisotropic superconducting gap probed by ${}^{125}$Te NMR in noncentrosymmetric Sc${}_{6}M$Te${}_2$ ($M$ = Fe, Co)
• Spontaneous magnetic field and disorder effects in BaPtAs_1-x_Sb_x_ with honeycomb network
• Fermi-surface diagnosis for topological superconductivity with $s$-wave-like pairing symmetries
• Possible Pairing Symmetry of BaPtAs${}_{1-x}$Sb${}_x$ with an Ordered Honeycomb Network