First-Principles Many-Body Investigation of Correlated Oxide Heterostructures: Few-Layer-Doped SmTiO$_3$

TL;DR

This study uses advanced first-principles methods to explore the complex electronic structure of doped SmTiO₃ heterostructures, revealing coexistence of different electronic phases and orbital behaviors.

Contribution

It demonstrates the effective combination of density functional theory and dynamical mean-field theory to analyze correlated oxide heterostructures.

Findings

Coexistence of insulating, metallic, and Mott-critical regions.

Orbital polarization varies between metallic and Mott layers.

Insight into the electronic complexity of doped SmTiO₃ heterostructures.

Abstract

Correlated oxide heterostructures pose a challenging problem in condensed matter research due to their structural complexity interweaved with demanding electron states beyond the effective single-particle picture. By exploring the correlated electronic structure of SmTiO$_3$ doped with few layers of SrO, we provide an insight into the complexity of such systems. Furthermore, it is shown how the advanced combination of band theory on the level of Kohn-Sham density functional theory with explicit many-body theory on the level of dynamical mean-field theory provides an adequate tool to cope with the problem. Coexistence of band-insulating, metallic and Mott-critical electronic regions is revealed in individual heterostructures with multi-orbital manifolds. Intriguing orbital polarizations, that qualitatively vary between the metallic and the Mott layers are also encountered.