3D Topological Kondo Insulators

TL;DR

This paper develops a self-consistent mean-field theory for topological Kondo insulators, revealing protected edge states and their spectral signatures through slab and bulk calculations.

Contribution

It introduces a slave-boson mean-field approach to study the topological properties of Kondo insulators in different geometries, highlighting edge state signatures.

Findings

Identification of protected edge states in slab geometry

Spectral function calculations confirm nontrivial topology

Bulk and surface band structures show topological features

Abstract

Topological Kondo insulators (TKIs) are new type of symmetry-protected topological insulators, which develop through the interplay of strong correlations and spin-orbit interactions. In these materials, the bulk is a perfect band insulator due to Kondo screening of localized moments via conduction electrons. Furthermore, strong spin-orbit coupling (SOC) and crystal field effect (CFE) of the localized moments result in a nonlocal odd-parity, time-reversal invariant hybridization between the local-moments and conduction bands, which creates a ground-state with nontrivial topology and gapless surface excitations (Physical Review Letters 104 (2010) 106408). In the present work, we develop a self-consistent theory to study topological Kondo insulators at the mean-field level. To achieve this, we apply slave-boson mean-field theory for a system with and without periodic boundary conditions, in order to study the system at bulk and slab geometry configuration. This enables us to observe a clear signature of protected edge states through band structure and calculation of spectral functions.