Nodeless Hybridization in Samarium Hexaboride defies current theory

Theory unanimously predicts 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 [1,2]. We have recently clarified the remaining questions regarding its surface states, and our results cast strong doubt on their topological nature. Here, we investigate the three-dimensional band structure of SmB6 and show that it is incompatible with a topological Kondo insulator which must have hybridization nodes at high-symmetry points [3]. In the talk, we will discuss the consequences of our finding. 

[1] L. Li, K. Sun, C. Kurdak, J. W. Allen, Nat. Rev. Phys. 82, 1 (2020)

[2] J. G. Checkelsky, B. A. Bernevig, P. Coleman, Q. Si, S. Paschen, Nat. Rev. Mater. 9, 509 (2024).

[3] E. D. L. Rienks et al., arXiv:2505.06449 (2025).