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M. Pickem, J. Tomczak, K. Held:
"Magnetism and pseudo gap physics in SrVO3 | SrTiO3 heterostructures";
Vortrag: DPG Fruehjahrstagung SKM, Regensburg, Germany; 31.03.2019 - 05.04.2019.

Modern atomic layer-by-layer deposition techniques allow for the study of materials in restricted geometries. Resulting effects of quantum confinement, e.g., in ultra-thin films are expected to be particularly pronounced for systems with strong electronic correlations. Indeed, the conventional Fermi-liquid state of bulk SrVO3 was recently discovered to be destroyed in films below a critical thickness.

On the basis of these result we perform state-of-the-art density functional theory (DFT) + dynamical mean-field theory (DMFT) calculations. We first compute susceptibilities within DMFT and find antiferromagnetic ordering in the undoped cases and evidence of competing phases when doping, opening perspectives for oxide-based spin-tronic devices.

In order to properly describe possible non-local correlation effects stemming from the reduced dimensionality and the (potential) proximity of long-range ordered phases, we additionally apply the dynamical vertex approximation - a promising method beyond DMFT - that was recently extended to realistic materials calculations. Preliminary results suggest the presence of pseudo-gap physics, vaguely reminiscent of cuprate superconductors. The encountered large self-energy corrections to the local (DMFT) descriptors advocate for further studies of thin films and heterostructure in both theory and experiment.