Distinct topological crystalline phases in models for the strongly correlated topological insulator SmB6

TL;DR

This paper identifies four distinct topological crystalline phases in models of the strongly correlated topological insulator SmB6, characterizing them with mirror Chern numbers and providing concrete tight-binding models.

Contribution

It proves the existence of four topological phases distinguished by mirror Chern numbers and offers explicit models for each, advancing understanding of topological crystalline phases in SmB6.

Findings

SmB6 exhibits four topological phases distinguished by mirror Chern numbers.

The paper provides concrete tight-binding models for each phase.

It concludes that SmB6 realizes a specific topological phase with given Chern numbers.

Abstract

SmB6 was recently proposed to be both a strong topological insulator and a topological crystalline insulator. For this and related cubic topological Kondo insulators, we prove the existence of four different topological phases, distinguished by the sign of mirror Chern numbers. We characterize these phases in terms of simple observables, and we provide concrete tight-binding models for each phase. Based on theoretical and experimental results for SmB6 we conclude that it realizes the phase with C^+_{k_z=0}=+2, C^+_{k_z=pi}=+1, C^+_{k_x=k_y}=-1, and we propose a corresponding minimal model.