Electron correlation and magnetism at the LaAlO${}_3$/SrTiO${}_3$ interface: A DFT+DMFT investigation

Abstract

We shed light on the interplay between structure and many-body effects relevant for itinerant ferromagnetism in LaAlO${}_3$/SrTiO${}_3$ heterostructures. The realistic correlated electronic structure is studied by means of the (spin-polarized) charge self-consistent combination of density functional theory (DFT) with dynamical mean-field theory (DMFT) beyond the realm of static correlation effects. Though many-body behavior is also active in the defect-free interface, a ferromagnetic instability occurs only with oxygen vacancies. A minimal Ti two-orbital $e_g$-$t_{2g}$ description for the correlated subspace is derived. Magnetic order affected by quantum fluctuations builds up from effective double exchange between nearly-localized $e_g$ and mobile $xy$ electrons.

refinements, final version

References in corpus (10)

• Magnetic effects at the interface between nonmagnetic oxides
• Origin of charge density at LaAlO3-on-SrTiO3 hetero-interfaces; possibility of intrinsic doping
• TRIQS: A Toolbox for Research on Interacting Quantum Systems
• Theory of spin-orbit coupling at LaAlO3/SrTiO3 interfaces and SrTiO3 surfaces
• Plane-wave based electronic structure calculations for correlated materials using dynamical mean-field theory and projected local orbitals
• Self-consistency over the charge-density in dynamical mean-field theory: a linear muffin-tin implementation and some physical implications
• Electron Correlation in Oxygen Vacancy in SrTiO${}_3$
• Approaching finite-temperature phase diagrams of strongly correlated materials: a case study for V2O3
• Ab initio study of the two-dimensional metallic state at the surface of SrTiO3: importance of oxygen vacancies
• Emerging magnetism and electronic phase separation at titanate interfaces

Cited by in corpus (13)

• Control of a two-dimensional electron gas on SrTiO3(111) by atomic oxygen
• Hubbard band or oxygen vacancy states in the correlated electron metal SrVO${}_3$?
• Electron dichotomy on the SrTiO${}_3$ defect surface augmented by many-body effects
• Electronic phase separation at LaAlO3/SrTiO3 interfaces tunable by oxygen deficiency
• Towards ab initio calculations with the dynamical vertex approximation
• Interface exchange processes in LaAlO${}_3$/SrTiO${}_3$ induced by oxygen vacancies
• Oxygen-vacancy driven electron localization and itinerancy in rutile-based TiO${}_2$
• Oxygen vacancies and hydrogen doping in LaAlO3/SrTiO3 heterostructures: electronic properties and impact on surface and interface reconstruction
• Group theory of Wannier functions providing the basis for a deeper understanding of magnetism and superconductivity
• Realistic many-body approaches to materials with strong nonlocal correlations
• Self-consistent DFT+$U$+$V$ study of oxygen vacancies in SrTiO${}_3$
• Oxide Heterostructures from a Realistic Many-Body Perspective
• La displacement driven Double-exchange like mediation in Titanium $d_{xy}$ ferromagnetism at the LaAlO${}_3$/SrTiO${}_3$