论文标题
NBRESI中完全传播超导性的证据：合并的$μ$ SR和NMR研究
Evidence of fully-gapped superconductivity in NbReSi: A combined $μ$SR and NMR study
论文作者
论文摘要
我们报告了一项对非中心对称NBRESI超导体的全面研究，该研究通过MUON-SPIN旋转和松弛（$ $ $ SR）和核磁共振（NMR）技术。 NBRESI是一个散装的超导体，具有$ T_C = 6.5 $ K，其特征是大型临界场，超过了Pauli限制。超级流体密度$ρ_\ mathrm {sc}（t）$（通过横向场$μ$ sr确定）和自旋 - 静态放松率$ t_1^{ - 1}（t）$（通过NMR确定）建议NBRESI中的Nodeless nodeless superdoductivity（SC）。我们还发现了Multigap SC的特征，在此证明了依赖于场的旋转宽松率和电子特异性热系数。从零场$μ$ $ SR的测量中表明，自发磁场的缺乏表明在NBRESI的超导状态下保留了时间反转的对称性。最后，我们讨论了NBRESI异常较大的上临界场的可能原因，这很可能是由于其各向异性晶体结构引起的。
We report a comprehensive study of the noncentrosymmetric NbReSi superconductor by means of muon-spin rotation and relaxation ($μ$SR) and nuclear magnetic resonance (NMR) techniques. NbReSi is a bulk superconductor with $T_c = 6.5$ K, characterized by a large upper critical field, which exceeds the Pauli limit. Both the superfluid density $ρ_\mathrm{sc}(T)$ (determined via transverse-field $μ$SR) and the spin-lattice relaxation rate $T_1^{-1}(T)$ (determined via NMR) suggest a nodeless superconductivity (SC) in NbReSi. We also find signatures of multigap SC, here evidenced by the field-dependent muon-spin relaxation rate and the electronic specific-heat coefficient. The absence of spontaneous magnetic fields below $T_c$, as evinced from zero-field $μ$SR measurements, indicates a preserved time-reversal symmetry in the superconducting state of NbReSi. Finally, we discuss possible reasons for the unusually large upper critical field of NbReSi, most likely arising from its anisotropic crystal structure.
