Topological aspect of Kondo insulator

Abstract

The experimental observations of the in-gap state by various measurements on a Kondo insulator provide a special and interesting character on the insulator. We show that the system is classified into the strong topological insulator leading to the topologically protected surface states within the gap on the surface and the in-gap states correspond to the surface states of the topological insulator. We argue the spectral functions and spin textures for different surfaces, comparing with recent angle resolved photoemission data. We also discuss the necessity of more sophisticated calculation in order to understand the whole picture of this compound.

Keywords:

• Topological insulator
• Kondo insulator
• surface spectral density
• spin texture

Notes

No potential conflict of interest was reported by the authors.

Department of Materials Science and Technology, Niigata University, Niigata, Japan.

1 Without the next-nearest-neighbor hybridization, the gap will not be opened along a high symmetry line because of the accidental high symmetry of the model.