Metal-Insulator transition in thin films and multilayers of early transition metal oxides from DFT+DMFT

We study the interplay between several control mechanisms on the emerging functionalities of complex oxide thin films and heterostructures composed of different early transition metal oxides, including correlated metals, Mott insulators and band insulators, using a combination of density functional theory (DFT) and dynamical mean-field theory (DMFT).
We discuss several examples where factors, such as e.g. substrate-induced epitaxial strain, dimensional confinement, and interface-related effects, lead to modifications of structural as well as electronic properties, resulting in metal-insulator transitions. For instance, we investigate interfacial charge transfer, electrostatics in polar heterostructures, and the evolution of octahedral rotations across an oxide-oxide interface between two materials with different rotation angles and/or tilt systems, and how these mechanisms affect the range of electronic reconstruction in the interfacial region. We show how these effects can give rise to phenomena such as metallic interfaces in multilayers of two Mott insulators, LaVO3 and LaTiO3, or a metal-insulator transition in the correlated metal CaVO3, for which we find that both tensile strain and a reduced film thickness can lead to a strong quasiparticle renormalization.