Abstract
We present angle-resolved photoemission studies on the rare-earth-hexaboride , which has recently been predicted to be a topological Kondo insulator. Our data do not agree with the prediction and instead show that exhibits a novel topological insulator state in the absence of a Kondo mechanism. We find that the Fermi level electronic structure of has three 2D Dirac cone like surface states enclosing the Kramers’s points, while the orbital that would be relevant for the Kondo mechanism is below the Fermi level. Our first-principles calculation shows that the topological state that we observe in is due to an inversion between Yb and B bands. These experimental and theoretical results provide a new approach for realizing novel correlated topological insulator states in rare-earth materials.
- Received 17 May 2014
DOI:https://doi.org/10.1103/PhysRevLett.114.016403
© 2015 American Physical Society