µSR study in superconducting state of nonsymmorphic compounds TIrGe (T = Ti, Zr, and Hf)

The search for novel topological phases, including topological semimetals (TSM) and topological superconductivity, has focused a significant amount of attention on the nonsymmorphic space group symmetry, which includes screw axis and glide plane symmetries. Recently, time-reversal symmetry breaking (TRSB) has been found in equiatomic ternary compounds, with Dirac point degeneracy protected by its nonsymmorphic crystal structure symmetry. The interplay of non-trivial band structure and strong spin-orbital coupling is believed to be responsible for the unconventional superconducting ground state in these compounds; however, the exact pairing mechanism is unknown. In this proposal, we propose to investigate the superconducting ground state of a new family of nonsymmorphic compounds.

对新型拓扑相（topological phases）的探索——包括拓扑半金属（topological semimetals, TSM）和拓扑超导（topological superconductivity）——已将大量研究注意力集中在非点式空间群对称性（nonsymmorphic space group symmetry）上，该对称性包含螺旋轴（screw axis）和滑移面（glide plane）对称性。近期，在等原子比三元化合物中发现了时间反演对称性破缺（time-reversal symmetry breaking, TRSB），其狄拉克点简并（Dirac point degeneracy）受非点式晶体结构对称性（nonsymmorphic crystal structure symmetry）保护。非平庸能带结构（non-trivial band structure）与强自旋轨道耦合（strong spin-orbital coupling）的相互作用被认为是这些化合物中非常规超导基态（unconventional superconducting ground state）的成因；然而，其确切的配对机制（pairing mechanism）仍未明确。本提案拟研究一类新型非点式化合物的超导基态。