2013/07/26 by Ye, Mengxing, Allen, J. W., Sun, Kai
#FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el)
paper · doi:10.48550/arxiv.1307.7191
We prove theoretically that certain strongly correlated Kondo insulators are topological crystalline insulators with nontrivial topology protected by crystal symmetries. In particular, we find that SmB6 is such a material. In addition to a nontrivial Z2 topological index protected by time reversal symmetry, SmB6 also has nontrival mirror Chern numbers protected by mirror symmetries. On the (100) surface of SmB6, the nontrivial mirror Chern numbers do not generate additional surface states beyond those predicted by the Z2 topological index. However, on the (110) surface, two more surface Dirac points are predicted. Remarkably, we find that for SmB6 both the Z2 topological index and the mirror Chern numbers are independent of microscopic details, which enables us to obtain surface state properties that are universal.