Nodeless Hybridization as Proof of Trivial Topology in Samarium Hexaboride

TL;DR

This paper challenges the classification of samarium hexaboride as a topological Kondo insulator by demonstrating the absence of hybridization nodes, providing new insights into its surface states and implications for future research in correlated topological insulators.

Contribution

It presents evidence that samarium hexaboride lacks the hybridization nodes expected in a topological Kondo insulator, redefining its topological nature and clarifying surface state characteristics.

Findings

Samarium hexaboride has nodeless hybridization, incompatible with a topological Kondo insulator.

Surface state data clarifies the nature of electronic states in SmB$_6$.

Implications for the search and identification of correlated topological insulators.

Abstract

Calculations unanimously predict samarium hexaboride to be a topological Kondo insulator, the first topological insulator driven by strong electron correlation. As of today it appears also experimentally established as the only representative of this material class. Here, we investigate the three-dimensional band structure of SmB$_6$ and show that it is incompatible with a topological Kondo insulator which must have hybridization nodes at high-symmetry points. In addition we clarify the remaining questions concerning the nature of the surface states with new data. We address consequences for the search for correlated topological insulators.