Topological Quantum Chemistry for heavy fermion systems

The formalism of topological quantum chemistry (TQC) has established a powerful framework to diagnose

and classify the topological properties of all band structures in all space groups. It has become one of the main

systematic approaches for the theoretical prediction and practical diagnosis of topological phases in materials.

However, it is unclear to which extent it remains applicable to the analysis of strongly-interacting electronic

systems. In this work, we address one of the many facettes of this problem by presenting a TQC-based general

formalism for the topological classification of correlated heavy fermion systems. In particular we focus on

Kondo and mixed valence insulators. This new framework fully accounts for the role played by crystal and time

reversal symmetries in the protection of topological band structures and is applicable to any space group, both

with and without spin-orbit coupling corrections. We apply our approach to the Kondo candidate Ce2I2Si2 and

the mixed-valence compound SmB6 . This analysis has lead us to a precise description of the real-space origin

of their topological valence bands, as well as to a refined classification in the case of SmB6 .