Electronic Structure of a Non-Symmorphic Kondo Lattice System CeAgSb₂

Topological Dirac semimetal with non-symmorphic symmetry (NSS) is one of the most recent discoveries in the field of novel topological quantum materials [1]. The uniqueness of this system is the presence of robust (including spin-orbit coupling) Dirac line nodes with NSS protection. CeAgSb₂, is a Kondo system, that exhibits a large anisotropic resistivity and a complex magnetic ground state at a lower temperature [2]. Employing angle-resolved photoemission spectroscopy (ARPES), we find that CeAgSb₂ possesses several non-trivial crossings near the Fermi level protected by the NSS. The ARPES data collected at different photon-energies suggest a quasi-2-D behavior which is consistent with the transport results. In addition, we observe energy bands of the surface-states in the near-Fermi-level region along with the non-trivial bulk bands that make the electronic structure complex. Our study shows the CeAgSb₂-family of materials as a new platform to study the robust non-symmorphic symmetry-protected Dirac semi-metallic systems with high spin-orbit coupling.



[1] L. M. Schoop et. al., Nat. Commun. 7, 11696 (2016).

[2] Y. Inada et. al., Philos. Mag. B, 82, 1867 (2002).