Orbital reconstruction and two-dimensional electron gas at the LaAlO3/SrTiO3 interface

Abstract

Conventional two-dimensional electron gases are realized by engineering the interfaces between semiconducting compounds. In 2004, Ohtomo and Hwang discovered that an electron gas can be also realized at the interface between large gap insulators made of transition metal oxides [1]. This finding has generated considerable efforts to clarify the underlying microscopic mechanism. Of particular interest is the LaAlO3/SrTiO3 system, because it features especially striking properties. High carrier mobility [1], electric field tuneable superconductivity [2] and magnetic effects [3], have been found. Here we show that an orbital reconstruction is underlying the generation of the electron gas at the LaAlO3/SrTiO3 n-type interface. Our results are based on extensive investigations of the electronic properties and of the orbital structure of the interface using X-ray Absorption Spectroscopy. In particular we find that the degeneracy of the Ti 3d states is fully removed, and that the Ti 3dxy levels become the first available states for conducting electrons.

12 pages, 3 figures

References in corpus (10)

• Magnetic effects at the interface between nonmagnetic oxides
• Why Some Interfaces Cannot be Sharp
• The role of oxygen vacancies in SrTiO3 at the LaAlO3/SrTiO3 interface
• High Mobility in LaAlO3/SrTiO3 Heterostructures: Origin, Dimensionality and Perspectives
• Origin of charge density at LaAlO3-on-SrTiO3 hetero-interfaces; possibility of intrinsic doping
• Mapping the Spatial Distribution of Charge Carriers in LaAlO3/SrTiO3 Heterostructures
• Avoiding the polarization catastrophe in LaAlO3 overlayers on SrTiO3(001) through a polar distortion
• Lattice relaxation, electronic screening, and spin and orbital phase diagram of LaTiO${}_3$/SrTiO${}_3$ superlattices
• Polar Discontinuity Doping of the LaVO_3/SrTiO_3 Interface
• Electronic structure induced reconstruction and magnetic ordering at the LaAlO${}_3|$SrTiO${}_3$ interface

Cited by in corpus (113)

• Unveiling a two-dimensional electron gas with universal subbands at the surface of SrTiO3
• A Universal Critical Density Underlying the Physics of Electrons at the LaAlO3/SrTiO3 Interface
• Two-dimensional quantum oscillations of the conductance at LaAlO3/SrTiO3 interfaces
• Orbital reflectometry
• Tailoring the nature and strength of electron-phonon interactions in the SrTiO${}_3$(001) two-dimensional electron liquid
• Critical thickness for ferromagnetism in LaAlO3/SrTiO3 heterostructures
• Subband structure of a two-dimensional electron gas formed at the polar surface of the strong spin-orbit perovskite KTaO${}_3$
• Built-in and induced polarization across LaAlO${}_3$/SrTiO${}_3$ heterojunctions
• Origin of interface magnetism in BiMnO3/SrTiO3 and LaAlO3/SrTiO3 heterostructures
• Electrolyte gate-controlled Kondo effect in SrTiO3
• Polaronic metal state at the LaAlO3/SrTiO3 interface
• Quasiparticle dynamics and spin-orbital texture of the SrTiO3 two-dimensional electron gas
• Ferromagnetic exchange, spin-orbit coupling and spiral magnetism at the LaAlO_3/SrTiO_3 interface
• Shubnikov-de Haas oscillations in SrTiO3\LaAlO3 interface
• Towards two-dimensional metallic behavior at LaAlO3/SrTiO3 interfaces
• Direct k-space mapping of the electronic structure in an oxide-oxide interface
• Polarity-induced oxygen vacancies at LaAlO3|SrTiO3 interfaces
• Oxygen vacancies at titanate interfaces: two-dimensional magnetism and orbital reconstruction
• Theory of the SrTiO3 Surface State Two-Dimensional Electron Gas
• Polar catastrophe and electronic reconstructions at the LaAlO3/SrTiO3 interface: evidence from optical second harmonic generation
• First-principles modeling of electrostatically doped perovskite systems
• Parallel electron-hole bilayer conductivity from electronic interface reconstruction
• Two-dimensional electron liquid state at LaAlO3-SrTiO3 interfaces
• Control of a two-dimensional electron gas on SrTiO3(111) by atomic oxygen
• Origin and Transport Signatures of Spin-Orbit Interactions in One- and Two-Dimensional SrTiO${}_3$-Based Heterostructures
• Orbital control in strained ultra-thin LaNiO${}_3$/LaAlO${}_3$ superlattices
• Massive symmetry breaking in LaAlO${}_3$/SrTiO${}_3$(111) quantum wells: a three-orbital, strongly correlated generalization of graphene
• Electron Accumulation and Emergent Magnetism in LaMnO3/SrTiO3 Heterostructures
• Giant negative magnetoresistance driven by spin-orbit coupling at the LAO/STO interface
• Mechanisms of charge transfer and redistribution in LaAlO3/SrTiO3 revealed by high-energy optical conductivity
• Localized vs. delocalized character of charge carriers in LaAlO3/ SrTiO3 superlattices
• Upper limit to magnetism in LaAlO3/SrTiO3 heterostructures
• Strong correlations elucidate the electronic structure and phase-diagram of LaAlO3/SrTiO3 interface
• Reversible modulation of orbital occupations via an interface-induced state in metallic manganites
• Toward an artificial Mott insulator: Correlations in confined, high-density electron liquids in SrTiO3
• Intrinsic instability of electronic interfaces with strong Rashba coupling
• Phase separation from electron confinement at oxide interfaces
• Tunable superconductivity at the oxide-insulator/KTaO${}_3$ interface and its origin
• Electronic Structure and Stability of Cs${}_2$TiX${}_6$ and Cs${}_2$ZrX${}_6$ (X$=$Br,I) Vacancy Ordered Double Perovskites
• Two-band superconductivity in doped SrTiO${}_3$ films and interfaces
• Multi-band superconductivity and nanoscale inhomogeneity at oxide interfaces
• Strong evidence for d-electron spin transport at room temperature at a LaAlO3/SrTiO3 interface
• Gate-tunable band structure of the LaAlO${}_3$-SrTiO${}_3$ interface
• Weak-localization and spin-orbit interaction in side-gate field effect devices at the LaAlO${}_3$/SrTiO${}_3$ interface
• Magnetic and Superconducting Ordering at LaAlO3/SrTiO3 Interfaces
• Large modulation of the Shubnikov-de Haas oscillations by the Rashba interaction at the LaAlO${}_3$/SrTiO${}_3$ interface
• A First-Principles Study of the Electronic Reconstructions of LaAlO3/SrTiO3 Heterointerfaces and Their Variants
• Anomalous orbital structure in a spinel-perovskite interface $\gamma$-Al${}_2$O${}_3$/SrTiO${}_3$
• Observation of a two-dimensional electron gas at the surface of annealed SrTiO3 single crystals by scanning tunneling spectroscopy
• New insights into the electron trapping mechanism in LaAlO_3 / SrTiO3 heterostructures
• Competition between electron pairing and phase coherence in superconducting interfaces
• Growth-induced electron mobility enhancement at the LaAlO${}_3$/SrTiO${}_3$ interface
• Phase diagrams of voltage-gated oxide interfaces with strong Rashba coupling
• Gate Tunable In- and Out-Of-Plane Spin-Orbit Coupling and Spin Splitting Anisotropy at LaAlO3/SrTiO3 (110) Interface
• Enhanced spin-orbit interaction and Kondo scattering in $\delta$-doped LaTiO${}_3$/SrTiO${}_3$ interfaces
• Electrically controlled superconducting states at the heterointerface SrTiO${}_3$/LaAlO${}_3$
• Inter-orbital topological superconductivity in spin-orbit coupled superconductors with inversion symmetry breaking
• Micrometer-scale ballistic transport of electron pairs in LaAlO3/SrTiO3 nanowires
• Localization of Two-dimensional Electron Gas in LaAlO3/SrTiO3 Heterostructures
• Magnetic and electronic properties at the gamma-Al2O3/SrTiO3 interface
• Absence of Giant Spin Splitting in the Two-Dimensional Electron Liquid at the Surface of SrTiO${}_3$ (001)
• Magneto-transport study of top- and back-gated LaAlO${}_3$/SrTiO${}_3$ heterostructures
• Band inversion driven by electronic correlations at the (111) LaAlO${}_3$/SrTiO${}_3$ interface
• Nanoscale rectification at the LaAlO3/SrTiO3 interface
• Electron degeneracy and intrinsic magnetic properties of epitaxial Nb:SrTiO${}_3$ thin-films controlled by defects
• Magnetic interactions at the nanoscale in trilayer titanates LaTiO${}_3$/SrTiO${}_3$/YTiO${}_3$
• Aperiodic quantum oscillations in the two-dimensional electron gas at the LaAlO3/SrTiO3 interface
• Tunable 2-dimensional/3-dimensional electron gases by submonolayer La doping of SrTiO_{3}
• Electronic structure of the SrTiO${}_3$/LaAlO${}_3$ interface revealed by resonant soft x-ray scattering
• Orientation Controlled Anisotropy in Single Crystals of Quasi-1D BaTiS3
• Band-Order Anomaly at the γ-Al2O3/SrTiO3 Interface Drives the Electron-Mobility Boost
• Large polarons as key quasiparticles in SrTiO3 and SrTiO3-based heterostructures
• Large Negative Electronic Compressibility of LaAlO3-SrTiO3 Interfaces with Ultrathin LaAlO3 Layers
• Microscopic understanding of the orbital splitting and its tuning at oxide interfaces
• Symmetry and correlation effects on band structure explain the anomalous transport properties of (111) LaAlO${}_3$/SrTiO${}_3$
• Symmetry breaking at the (111) interfaces of SrTiO${}_3$ hosting a 2D-electron system
• Evolution of the SrTiO${}_3$ surface electronic state as a function of LaAlO${}_3$ overlayer thickness
• Derivation of effective spin-orbit Hamiltonians and spin lifetimes, with application to SrTiO${}_3$ heterostructures
• Thermally excited multi-band conduction in LaAlO3/SrTiO3 heterostructures exhibiting magnetic scattering
• Inhomogeneous multi-carrier superconductivity at LaXO3/SrTiO3 (X=Al or Ti) oxide interfaces
• The Conducting Channel at the LaAlO${}_3$/SrTiO${}_3$ Interface
• Correlation between Superconductivity, Band Filling and Electron Confinement at the LaAlO${}_3$-SrTiO${}_3$ Interface
• Hallmarks of non-trivial topology in Josephson junctions based on oxide nanochannels
• Signature of enhanced spin-orbit interaction in the magnetoresistance of LaTiO${}_3$/SrTiO${}_3$ interfaces on $\delta$-doping
• Raman and fluorescence contributions to resonant inelastic soft x-ray scattering on LaAlO${}_3$/SrTiO${}_3$ heterostructures
• The mechanism of spin-orbit coupling in a 2D oxide interface
• Theoretical models of Rashba spin splitting in asymmetric SrTiO3-based heterostructures
• Local electronic structures on the superconducting interface $LaAl{O}_3/SrTi{O}_3$
• Interplay between singlet and triplet pairings in multi-band two-dimensional oxide superconductors
• Unconventional crystal field splitting in non-centrosymmetric BaTiO${}_3$ thin films
• Probing Quantum Confinement and Electronic Structure at Polar Oxide Interfaces
• Hydrostatic pressure response of an oxide two-dimensional electron system
• Engineered Kondo screening and nonzero Berry phase in SrTiO3/LaTiO3/SrTiO3 heterostructures
• Atomically-Smooth Single-Crystalline VO${}_2$ thin films with Bulk-like Metal-Insulator Transitions
• Long-range electronic reconstruction to a $d_{xz,yz}$-dominated Fermi surface below the LaAlO${}_3$/SrTiO${}_3$ interface
• Transport in strongly-coupled graphene-LaAlO3/SrTiO3 hybrid systems
• Two-dimensional electron systems in perovskite oxide heterostructures: Role of the polarity-induced substitutional defects
• Observation of transient superconductivity at the LaAlO${}_3$/SrTiO${}_3$ interface
• Ballistic transport through quantum point contacts of multi-orbital oxides
• Density inhomogeneities and Rashba spin-orbit coupling interplay in oxide interfaces
• Visualizing quantum phenomena at complex oxide interfaces: an atomic view from scanning transmission electron microscopy
• Nano-engineering of electron correlation in oxide superlattices
• Spin-orbit controlled quantum capacitance of a polar heterostructure
• Depth resolved chemical speciation of a superlattice structure
• Coexistence of high electron-mobility, unpaired spins, and superconductivity at high carrier density SrTiO${}_3$-based interfaces
• Orthorhombic distortion drives orbital ordering in an antiferromagnetic 3$d^1$ Mott insulator
• Resolving interfacial charge transfer in titanate superlattices using resonant X-ray reflectometry
• Magnetism and nonlinear charge transport in NiFe2O4/γ-Al2O3/SrTiO3 heterostructure: Toward Spintronic Applications
• Constructing oxide interfaces and heterostructures by atomic layer-by-layer laser molecular beam epitaxy
• Quantized conductance in a one-dimensional ballistic oxide nanodevice
• Origin of the dome-shaped superconducting phase diagram in ${\mathrm{SrTiO}}_3$-based interfaces
• Absence of localized $5d^1$ electrons in KTaO${}_3$ interface superconductors
• Single-band to two-band superconductivity transition in two-dimensional oxide interfaces