Magnetic Weyl and Dirac Kondo semimetal phases in heterostructures

TL;DR

This paper explores heterostructures of Kondo insulators, demonstrating that magnetic ordering can induce topological semimetal phases such as Weyl and Dirac Kondo semimetals, offering a new platform for strongly correlated topological materials.

Contribution

It introduces a new class of heterostructures that can host magnetic Weyl and Dirac Kondo semimetal phases through specific magnetic orderings.

Findings

Ferromagnetic order leads to magnetic Weyl Kondo semimetals.

Antiferromagnetic order can produce magnetic Dirac Kondo semimetals.

Both type-I and type-II phases are possible in these heterostructures.

Abstract

We study a layered three-dimensional heterostructure in which two types of Kondo insulators are stacked alternatingly. One of them is the topological Kondo insulator SmB 6 , the other one an isostructural Kondo insulator AB 6 , where A is a rare-earth element, e.g., Eu, Yb, or Ce. We find that if the latter orders ferromagnetically, the heterostructure generically becomes a magnetic Weyl Kondo semimetal, while antiferromagnetic order can yield a magnetic Dirac Kondo semimetal. We detail both scenarios with general symmetry considerations as well as concrete tight-binding calcu-lations and show that type-I as well as type-II magnetic Weyl/Dirac Kondo semimetal phases are possible in these heterostructures. Our results demonstrate that Kondo insulator heterostructures are a versatile platform for design of strongly correlated topological semimetals.