Samarium hexaboride is a candidate for the topological Kondo insulator state, in which Kondo coherence is predicted to give rise to an insulating gap spanned by topological surface states. Here we investigate the surface and bulk electronic properties of magnetically alloyed Sm1-xMxB6 (M=Ce, Eu), using angle-resolved photoemission spectroscopy (ARPES) and complementary characterization techniques. Remarkably, topologically nontrivial bulk and surface band structures are found to persist in highly modified samples with up to 30% Sm substitution, and to coexist with antiferromagnetism in the case of Eu doping. The results are interpreted in terms of a hierarchy of energy scales, in which surface state emergence is linked to the formation of a direct Kondo gap, while low temperature transport trends depend on the indirect gap.
@article{arxiv.1907.07074,
title = {Robust surface states and coherence phenomena in magnetically alloyed SmB6},
author = {Lin Miao and Chul-Hee Min and Yishuai Xu and Zengle Huang and Erica C. Kotta and Rourav Basak and M. S. Song and B. Y. Kang and B. K. Cho and K. Kißner and Friedrich Reinert and Turgut Yilmaz and Elio Vescovo and Yi-De Chuang and Weida Wu and Jonathan D. Denlinger and L. Andrew Wray},
journal= {arXiv preprint arXiv:1907.07074},
year = {2021}
}