Superconducting characteristics and pairing symmetry in uranium based heavy fermion superconductors studied by nuclear magnetic resonance

本文对UBe_3单晶进行了^9Be核磁共振（NMR）测量，<13>以阐明其超导电性机制。从^9Be NMR测量的场角依赖性来看，垂直于镜面的Be 2 p轨道主要对导带有贡献。在超导状态下，我们发现H的^9 Be-NMR Knight位移||[001]这一点没有改变。这一结果与UBe_2中的自旋三重态配对相一致<13>。此外，在RF表面阻抗测量中观察到的不寻常行为表明<13>UBe_2具有多个超导相。

^9Be Nuclear Magnetic Resonance (NMR) measurements were carried out for a single crystal UBe_<13> in order to clarify its mechanism of superconductivity. From the field-angle-dependence of ^9Be NMR measurements, the Be 2p orbital perpendicular to the mirror plane contributes mainly to the conduction band. In the superconducting state, we found that ^9Be-NMR Knight shift for H||[001] does not change at all. This result is consistent with the spin-triplet pairing state in UBe_<13>. In addition, unusual behavior observed in RF surface impedance measurements suggest that UBe_<13> has multiple superconducting phases.