3D Topological Kondo Insulators

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.