Bae Seokjin, Kim Hyunsoo, Eo Yun Suk, Ran Sheng, Liu I-Lin, Fuhrman Wesley T, Paglione Johnpierre, Butch Nicholas P, Anlage Steven M
Maryland Quantum Materials Center, Department of Physics, University of Maryland, College Park, MD, USA.
Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, IL, USA.
Nat Commun. 2021 May 11;12(1):2644. doi: 10.1038/s41467-021-22906-6.
Chiral superconductors have been proposed as one pathway to realize Majorana normal fluid at its boundary. However, the long-sought 2D and 3D chiral superconductors with edge and surface Majorana normal fluid are yet to be conclusively found. Here, we report evidence for a chiral spin-triplet pairing state of UTe with surface normal fluid response. The microwave surface impedance of the UTe crystal was measured and converted to complex conductivity, which is sensitive to both normal and superfluid responses. The anomalous residual normal fluid conductivity supports the presence of a significant normal fluid response. The superfluid conductivity follows the temperature behavior predicted for an axial spin-triplet state, which is further narrowed down to a chiral spin-triplet state with evidence of broken time-reversal symmetry. Further analysis excludes trivial origins for the observed normal fluid response. Our findings suggest that UTe can be a new platform to study exotic topological excitations in higher dimension.
手性超导体已被提议作为在其边界实现马约拉纳正常流体的一种途径。然而，人们长期寻找的具有边缘和表面马约拉纳正常流体的二维和三维手性超导体尚未得到确凿发现。在此，我们报告了UTe存在具有表面正常流体响应的手性自旋三重态配对态的证据。我们测量了UTe晶体的微波表面阻抗并将其转换为复电导率，复电导率对正常和超流体响应均敏感。异常的残余正常流体电导率支持存在显著的正常流体响应。超流体电导率遵循轴向自旋三重态态所预测的温度行为，通过时间反演对称性破缺的证据进一步将其缩小到手性自旋三重态态。进一步分析排除了所观察到的正常流体响应的平凡起源。我们的发现表明，UTe可以成为研究高维奇异拓扑激发的新平台。
