Cubic Topological Kondo Insulators

TL;DR

This paper develops a theory for cubic topological Kondo insulators, highlighting how spin quartets influence their topological properties and lead to multiple Dirac cones with heavy quasiparticles.

Contribution

It introduces a novel theoretical framework for cubic topological Kondo insulators involving spin quartets, expanding understanding beyond tetragonal models.

Findings

Elimination of weak-topological phases in cubic Kondo insulators.

Presence of three Dirac cones with heavy quasiparticles at specific Brillouin zone points.

Topological behavior localized at X or M points in the Brillouin zone.

Abstract

Current theories of Kondo insulators employ the interaction of conduction electrons with localized Kramers doublets originating from a tetragonal crystalline environment, yet all Kondo insulators are cubic. Here we develop a theory of cubic topological Kondo insulators involving the interaction of spin quartets with a conduction sea. The spin quartets greatly increase the potential for strong topological insulators, entirely eliminating the weak-topological phases from the diagram. We show that the relevant topological behavior in cubic Kondo insulators can only reside at the lower symmetry X or M points in the Brillouin zone, leading to a three Dirac cones with heavy quasiparticles.