Origin of charge density at LaAlO3-on-SrTiO3 hetero-interfaces; possibility of intrinsic doping

Abstract

As discovered by Ohtomo et al., a large sheet charge density with high mobility exists at the interface between SrTiO3 and LaAlO3. Based on transport, spectroscopic and oxygen-annealing experiments, we conclude that extrinsic defects in the form of oxygen vacancies introduced by the pulsed laser deposition process used by all researchers to date to make these samples is the source of the large carrier densities. Annealing experiments show a limiting carrier density. We also present a model that explains the high mobility based on carrier redistribution due to an increased dielectric constant.

14 pages, 3 figures, 1 table; accepted for publication in Phys. Rev. Lett.

Cited by in corpus (64)

• Magnetic effects at the interface between nonmagnetic oxides
• Electric Field Control of the LaAlO${}_3$/SrTiO${}_3$ Interface Ground State
• High Mobility in LaAlO3/SrTiO3 Heterostructures: Origin, Dimensionality and Perspectives
• Avoiding the polarization catastrophe in LaAlO3 overlayers on SrTiO3(001) through a polar distortion
• Polar Discontinuity Doping of the LaVO_3/SrTiO_3 Interface
• High mobility conduction at (110) and (111) LaAlO3/SrTiO3 interfaces
• Surface defects and conduction in polar oxide heterostructures
• Origin of Metallic States at Heterointerface between Band Insulators LaAlO${}_3$ and SrTiO${}_3$
• Polarity-induced oxygen vacancies at LaAlO3|SrTiO3 interfaces
• Oxygen vacancies at titanate interfaces: two-dimensional magnetism and orbital reconstruction
• Polar catastrophe and electronic reconstructions at the LaAlO3/SrTiO3 interface: evidence from optical second harmonic generation
• Control of a two-dimensional electron gas on SrTiO3(111) by atomic oxygen
• Electron Accumulation and Emergent Magnetism in LaMnO3/SrTiO3 Heterostructures
• Mechanisms of charge transfer and redistribution in LaAlO3/SrTiO3 revealed by high-energy optical conductivity
• Electronic structure induced reconstruction and magnetic ordering at the LaAlO${}_3|$SrTiO${}_3$ interface
• Nature of weak magnetism in SrTiO3/LaAlO3 multilayers
• Strong electronic correlation and strain effects at the interfaces between polar and nonpolar complex oxides
• Electronic reconstruction at the isopolar LaTiO3/LaFeO3 interface: An x-ray photoemission and density functional theory study
• Ferroelectric Dead Layer Driven by a Polar Interface
• Gate-tunable band structure of the LaAlO${}_3$-SrTiO${}_3$ interface
• Fundamental asymmetry in interfacial electronic reconstruction between insulating oxides
• Localized versus itinerant states created by multiple oxygen vacancies in SrTiO3
• Electronic properties of buried hetero-interfaces of LaAlO3 on SrTiO3
• Novel photo-conducting state and its perturbation by electrostatic fields in oxide-based two-dimensional electron gas
• Modulation Doping of a Mott Quantum Well by a Proximate Polar Discontinuity
• Enhanced persistent photoconductivity in $\delta$-doped LaAlO${}_3$/SrTiO${}_3$ heterostructures
• Accumulation, inversion, and depletion layers in SrTiO${}_3$
• Depth-Resolved Subsurface Defects in Chemically Etched SrTiO3
• Optically excited multi-band conduction in LaAlO3/SrTiO3 heterostructures
• Magnetic-field induced resistivity minimum with in-plane linear magnetoresistance of the Fermi liquid in SrTiO3-x single crystals
• Appearance and disappearance of ferromagnetism in ultra-thin LaMnO${}_3$ on SrTiO${}_3$ substrate: a viewpoint from first-principles
• Electron energy loss spectroscopy determination of Ti oxidation state at the (001) LaAlO3/SrTiO3 interface as a function of LaAlO3 growth conditions
• Tuning the two-dimensional electron liquid at oxide interfaces by buffer-layer-engineered redox reactions
• Anisotropic electrical resistance in mesoscopic LaAlO${}_3$/SrTiO${}_3$ devices with individual domain walls
• Electronic structure of the SrTiO${}_3$/LaAlO${}_3$ interface revealed by resonant soft x-ray scattering
• Relaxation of transport properties in electron doped SrTiO3
• Self-consistent iteration procedure in analyzing reflectivity and spectroscopic ellipsometry data of multilayered materials and their interfaces
• A two-dimensional electron gas based on a 5s oxide with high room-temperature mobility and strain sensitivity
• Two components for one resistivity in LaVO3/SrTiO3 heterostructures
• Dynamics of photo-generated non-equilibrium electronic states in Ar${}^{+}$ ion irradiated SrTiO${}_3$
• Stoichiometry Dependence of Potential Screening at La${}_{(1-\delta )}$Al${}_{(1+\delta )}$O${}_3$/SrTiO${}_3$ Interfaces
• Anisotropic electronic transport of the two-dimensional electron system in Al2O3/SrTiO3 heterostructures
• Tunable spin and orbital polarization in SrTiO3-based heterostructures
• Influence of oxygen pressure and aging on LaAlO3 films grown by pulsed laser deposition on SrTiO3 substrates
• Engineered Kondo screening and nonzero Berry phase in SrTiO3/LaTiO3/SrTiO3 heterostructures
• Interplay between sheet resistance increase and magnetotransport properties in $\mathrm{LaAl}{\mathrm{O}}_3/\mathrm{SrTi}{\mathrm{O}}_3$
• Oxide tunnel junctions supporting a two-dimensional electron gas
• Nature of electrons from oxygen vacancies and polar catastrophe at LaAlO3/SrTiO3 interfaces
• Transport and thermoelectric properties of the LaAlO${}_3$/SrTiO${}_3$ interface
• Superconductivity in epitaxially grown LaVO3/KTaO3(111) heterostructures
• Gate voltage control of the $Al{O}_x$/$SrTi{O}_3$ interface electrical properties
• Ultrafast Modification of the Polarity at LaAlO${}_3$/SrTiO${}_3$ Interfaces
• Electrostatic tuning of magnetism at the conducting (111) (La${}_{0.3}$Sr${}_{0.7}$)(Al${}_{0.65}$Ta${}_{0.35}$)/SrTiO${}_3$ interface
• Understanding the role of exchange and correlations in complex oxides under strain and oxide heterostructures
• Critical role of terminating layer in formation of 2DEG state at the $LaIn{O}_3$/$BaSn{O}_3$ interface
• In situ investigation of conducting interface formation in LaAlO3/SrTiO3 heterostructure
• Polarity-field driven conductivity in SrTiO${}_3$/LaAlO${}_3$: a hybrid functional study
• Two-Dimensional Charge Localization at the Perovskite Oxide Interface
• Large electropositive cations as surfactants for the growth of polar epitaxial films
• Constructing oxide interfaces and heterostructures by atomic layer-by-layer laser molecular beam epitaxy
• General considerations of the electrostatic boundary conditions in oxide heterostructures
• High-sensitivity of initial SrO growth on the residual resistivity in epitaxial thin films of SrRuO${}_3$ on SrTiO${}_3$ (001)
• Temperature dependent giant resistance anomaly in LaAlO3/SrTiO3 nanostructures
• Coupling between tilts and charge carriers at polar-nonpolar perovskite interfaces