Surface-state spin textures and mirror Chern numbers in topological Kondo insulators

TL;DR

This paper investigates the spin textures of surface states in topological Kondo insulators, establishing relationships between hybridization, mirror Chern numbers, and observable spin textures, supported by numerical models of samarium hexaboride.

Contribution

It provides a new classification framework linking hybridization, mirror Chern numbers, and spin textures in topological Kondo insulators.

Findings

Derived relationships between hybridization matrices and mirror Chern numbers.

Classified surface-state spin textures based on topological invariants.

Numerical models confirm theoretical predictions for samarium hexaboride.

Abstract

The recent discovery of topological Kondo insulators has triggered renewed interest in the well-known Kondo insulator samarium hexaboride, which is hypothesized to belong to this family. In this Letter, we study the spin texture of the topologically protected surface states in such a topological Kondo insulator. In particular, we derive close relationships between (i) the form of the hybridization matrix at certain high-symmetry points, (ii) the mirror Chern numbers of the system, and (iii) the observable spin texture of the topological surface states. In this way, a robust classification of topological Kondo insulators and their surface-state spin texture is achieved. We underpin our findings with numerical calculations of several simplified and realistic models for systems like samarium hexaboride.