论文标题
在非中心对称lanic2中的两间隙时间逆转对称性破坏超导性
Two-Gap Time Reversal Symmetry Breaking Superconductivity in Non-Centrosymmetric LaNiC2
论文作者
论文摘要
我们报告了单晶形式的非中心对称超导体（LANIC $ _2 $）的$μ$ SR调查。与以前的$μ$ $ SR研究相比，对非中心对称超导多晶和粉末样品的研究明确的方向可以同时测定磁性渗透深度的异常值，以及从探测Vortex状态的磁场分布的磁场核心大小的涡旋核心大小的涡流大小。这些数量的磁场依赖性明确地证明了存在两个无节性的超导能量间隙。此外，我们在超导阶段检测到弱的内部磁场，证实了较早的$ $ $ $ SR证据证明了时间交流对称性破坏超导状态。我们的结果表明，LANIC $ _2 $中的Cooper配对的特征是引入了相同的内晶间平等配对模型，以描述中心对称超导体LANIGA $ _2 $中的配对状态。
We report a $μ$SR investigation of a non-centrosymmetric superconductor (LaNiC$_2$) in single crystal form. Compared to previous $μ$SR studies of non-centrosymmetric superconducting polycrystalline and powder samples, the unambiguous orientation of single crystals enables a simultaneous determination of the absolute value of the magnetic penetration depth and the vortex core size from measurements that probe the magnetic field distribution in the vortex state. The magnetic field dependence of these quantities unambiguously demonstrates the presence of two nodeless superconducting energy gaps. In addition, we detect weak internal magnetic fields in the superconducting phase, confirming earlier $μ$SR evidence for a time-reversal symmetry breaking superconducting state. Our results suggest that Cooper pairing in LaNiC$_2$ is characterized by the same interorbital equal-spin pairing model introduced to describe the pairing state in the centrosymmetric superconductor LaNiGa$_2$.
