Correlated Topological Insulators with Mixed Valence

TL;DR

This paper introduces a first-principles LDA+Gutzwiller method with Green's function to study correlated topological insulators, revealing SmB6 as a strongly correlated TI with three Dirac cones on its surface.

Contribution

It develops a novel computational approach combining LDA+Gutzwiller and Green's function techniques for correlated topological materials.

Findings

SmB6 exhibits non-trivial Z2 topology.

SmB6 has three Dirac cones on its surface.

The method effectively captures topological features in correlated systems.

Abstract

We propose the local density approximation (LDA)+Gutzwiller method incorporating Green's function scheme to study the topological physics of correlated materials from the first-principles. Applying this method to typical mixed valence materials SmB6, we found its non-trivial Z2 topology, indicating that SmB6 is a strongly correlated topological insulator (TI). The unique feature of this compound is that its surface states contain three Dirac cones in contrast to most known TIs.