Coexistence of the hourglass and nodal-line dispersions in Nb₃SiTe₆ revealed by ARPES

The non-symmorphic crystal symmetry protection in the layered topological semimetal Nb₃SiTe₆ can generate exotic band crossings. Herein, high-quality Nb₃SiTe₆ single crystal was synthesized via chemical vapor transport. The lattice structure of Nb₃SiTe₆ was characterized by scanning transmission electron microscopy, X-ray diffraction, core-level photoemission, and Raman spectroscopies. Angle-resolved photoemission spectroscopy was used to reveal its topological properties by presenting band structures along different high-symmetry directions. Our data show that nontrivial band features coexist in Nb₃SiTe₆, including an hourglass-type dispersion formed by two bands along the S-R high-symmetry line, two node lines along the S-X path and the S-R-U path, respectively. These results provide a context for the understanding and exploration of the exotic topological properties of Nb₃SiTe₆.