Abstract
We investigated the crystal-electric field ground state of the manifold in the strongly correlated topological insulator using core-level nonresonant inelastic x-ray scattering. The directional dependence of the scattering function that arises from higher multipole transitions establishes unambiguously that the quartet state of the Sm configuration governs the ground-state symmetry and, hence, the topological properties of . Our findings contradict the results of density functional calculations reported so far.
- Received 20 June 2017
- Revised 25 September 2017
DOI:https://doi.org/10.1103/PhysRevLett.120.016402
© 2018 American Physical Society