Topological Kondo insulators and semimetals*

The electrons in heavy fermion materials experience strong spin-orbit cou- pling interactions that greatly exceed their kinetic energy. It has long been known that the spin-orbit coupling stabilizes new kinds of heavy fermion metals, superconductors and Kondo insulators and semimetals. In this talk, I will discuss the new realization that spin orbit coupling changes the topology leading to new kinds of topological orders. I will mainly focus on SmB6, CeNiSn and time permitting CeSb. In particular, I will discuss the puzzling experimental results on topological Kondo insulators and the possibility of a Skyrme insulating phase in SmB6 [1]. Next I will discuss how non-symmorphic symmetries can lead to Mobius-twisted surface states in failed Kondo insulators[2]. Time permitting, I will discuss recent ARPES experiments on gapless Kondo-Weyl semimetals[3].

[1] O. Erten, P.-Y. Chang, P. Coleman, A. Tsvelik Phys. Rev. Lett. 119, 057603 (2017).
[2] P.-Y. Chang, O. Erten, P. Coleman, Nature Physics 13, 794 (2017).
[3] S. Jang, R. Kealhofer, C. John, S. Doyle, J. Hong, J. Shim, Q. Si, O. Erten, J. D. Denlinger, J. G. Analytis, arXiv:1712.05817 (2017).