Interface relaxation and electrostatic charge depletion in the oxide heterostructure LaAlO3/SrTiO3

Abstract

Performing an analysis within density functional theory, we develop insight into the structural and electronic properties of the oxide heterostructure LaAlO3/SrTiO3. Electrostatic surface effects are decomposed from the internal lattice distortion in order to clarify their interplay. We first study the interface relaxation by a multi-layer system without surface, and the surface effects, separately, by a substrate-film system. While elongation of the TiO6 octahedra at the interface enhances the metallicity, reduction of the film thickness has the opposite effect due to a growing charge depletion. The interplay of these two effects, as reflected by the full lattice relaxation in the substrate-film system, however, strongly depends on the film thickness. An inversion of the TiO6 distortion pattern for films thinner than four LaAlO3 layers results in an insulating state.

10 pages, 7 figures, accepted by Europhysics Letters

References in corpus (15)

• High Mobility in LaAlO3/SrTiO3 Heterostructures: Origin, Dimensionality and Perspectives
• Mapping the Spatial Distribution of Charge Carriers in LaAlO3/SrTiO3 Heterostructures
• Lattice relaxation, electronic screening, and spin and orbital phase diagram of LaTiO${}_3$/SrTiO${}_3$ superlattices
• Origin of Metallic States at Heterointerface between Band Insulators LaAlO${}_3$ and SrTiO${}_3$
• Electronic structure induced reconstruction and magnetic ordering at the LaAlO${}_3|$SrTiO${}_3$ interface
• Lattice polarization effects on electron-gas charge densities in ionic superlattices
• Surface Effects on Oxide Heterostructures
• Exponential decay of relaxation effects at LaAlO3/SrTiO3 heterointerfaces
• Intrinsic Doping at YBCO-metal Interfaces: Quantitative Results
• Electron energy loss spectroscopy determination of Ti oxidation state at the (001) LaAlO3/SrTiO3 interface as a function of LaAlO3 growth conditions
• Charge redistribution at YBa2Cu3O7-metal interfaces
• Electronic structure of the c(4 x 2) reconstructed Ge(001) surface
• Electronic Interface Reconstruction at Polar-Nonpolar Mott Insulator Heterojunctions
• Interface hole-doping in cuprate-titanate superlattices
• Self-assembled Pt nanowires on Ge(001): Relaxation effects

Cited by in corpus (7)

• Locally enhanced conductivity due to the tetragonal domain structure in LaAlO${}_3$/SrTiO${}_3$ heterointerfaces
• Evolution of the interfacial structure of LaAlO3 on SrTiO3
• Polarity-induced oxygen vacancies at LaAlO3|SrTiO3 interfaces
• Two-dimensional electron liquid state at LaAlO3-SrTiO3 interfaces
• Metal-insulator transition at the LaAlO3/SrTiO3 interface revisited: A hybrid functional study
• Electric-field-induced pyroelectric order and localization of the confined electrons in LaAlO3/SrTiO3 heterostructures
• Influence of the vacuum interface on the charge distribution in V2O3 thin films