Topological Kondo Insulators

TL;DR

This paper reviews the emergence of topological Kondo insulators, highlighting how strong correlations and spin-orbit interactions lead to topological surface states, with experimental evidence from Samarium hexaboride supporting theoretical predictions.

Contribution

It synthesizes recent theoretical models and experimental findings, demonstrating the topological nature of Kondo insulators like Samarium hexaboride.

Findings

Hybridization induces topological insulating behavior.

Experimental surface states confirm theoretical predictions.

Residual conductivity arises from robust surface states.

Abstract

This article reviews recent theoretical and experimental work on a new class of topological material - topological Kondo insulators, which develop through the interplay of strong correlations and spin-orbit interactions. The history of Kondo insulators is reviewed along with the theoretical models used to describe these heavy fermion compounds. The Fu-Kane method of topological classification of insulators is used to show that hybridization between the conduction electrons and localized f-electrons in these systems gives rise to interaction-induced topological insulating behavior. Finally, some recent experimental results are discussed, which appear to confirm the theoretical prediction of the topological insulating behavior in Samarium hexaboride, where the long-standing puzzle of the residual low-temperature conductivity has been shown to originate from robust surface states.