Multitype Dirac fermions protected by orthogonal glide symmetries in a noncentrosymmetric system

Article

关键词: QUASI-PARTICLE INTERFERENCE;    MAJORANA FERMIONS;    SEMIMETAL;    SCHEMES;    CATALOG;   

DOI  :  10.1103/PhysRevB.102.041201

来源: SCIE

【 摘 要 】

Compared to inversion-symmetric systems, the emerging bulk Dirac point (DP) in noncentrosymmetric systems is much harder and its symmetry-protection mechanism is poorly understood. In this Rapid Communication, we propose that orthogonal glide symmetries can protect two distinct types of bulk anisotropic DPs. One is the ordinary anisotropic DP that is doubly degenerate only along one invariant axis, which results from symmetry-protected accidental band crossing. The other one is a symmetry-enforced DP fixed at a non-time-reversal-invariant point, which is doubly degenerate at three orthogonal directions. This unique topological phase is exemplified by KSnSe2 in space group 108. Our work not only unveils a unique symmetry-protection mechanism but also provides a material candidate for exploring multitype Dirac fermions in noncentrosymmetric systems.

【 授权许可】

Free