Tuning the two-dimensional electron gas at the LaAlO3/SrTiO3(001) interface by metallic contacts

Abstract

First principles calculations reveal that adding a metallic overlayer on LaAlO3/SrTiO3(001) eliminates the electric field within the polar LaAlO3 film and thus suppresses the thickness-dependent insulator-to-metal transition observed in uncovered films. Independent of the LaAlO3 thickness both the surface and the interface are metallic, with an enhanced interface carrier density relative to LaAlO3/SrTiO3(001) after the metallization transition. Moreover, a monolayer thick metallic Ti-contact exhibits a finite magnetic moment and for a thin SrTiO3-substrate induces a spin-polarized 2D electron gas at the n-type interface due to confinement effects. A diagram of band alignment in M/LaAlO3/SrTiO3(001) and Schottky barriers for M=Ti, Al, and Pt are provided.

4 pages, 4 figures, submitted for publication

References in corpus (18)

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• Coexistence of Magnetic Order and Two-dimensional Superconductivity at LaAlO${}_3$/SrTiO${}_3$ Interfaces
• Unveiling a two-dimensional electron gas with universal subbands at the surface of SrTiO3
• Creation and control of a two-dimensional electron liquid at the bare SrTiO3 surface
• Coexistence of superconductivity and ferromagnetism in two dimensions
• Avoiding the polarization catastrophe in LaAlO3 overlayers on SrTiO3(001) through a polar distortion
• Ferroelectricity in ultra-thin perovskite films
• Instability, Intermixing and Electronic Structure at the Epitaxial LaAlO3/SrTiO3(001) Heterojunction
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• "Water-cycle" mechanism for writing and erasing nanostructures at the LaAlO3/SrTiO3 interface
• Surface defects and conduction in polar oxide heterostructures
• Evolution of the interfacial structure of LaAlO3 on SrTiO3
• Polarity-induced oxygen vacancies at LaAlO3|SrTiO3 interfaces
• First-principles modeling of electrostatically doped perovskite systems
• Charge writing at the LaAlO3/SrTiO3 surface
• Tunable 2-dimensional/3-dimensional electron gases by submonolayer La doping of SrTiO_{3}
• Diodes with Breakdown Voltages Enhanced by the Metal-Insulator Transition of LaAlO${}_3$-SrTiO${}_3$ Interfaces

Cited by in corpus (14)

• A polarity-induced defect mechanism for conductivity and magnetism at polar-nonpolar oxide interfaces
• Origin of two-dimensional electron gases at oxide interfaces: insights from theory
• Controlling the density of the 2DEG at the SrTiO3/LaAlO3 interface
• Quantum-Matter Heterostructures
• Hard x-ray photoemission and density functional theory study of the internal electric field in SrTiO3/LaAlO3 oxide heterostructures
• Strong evidence for d-electron spin transport at room temperature at a LaAlO3/SrTiO3 interface
• Ab initio study of the two-dimensional metallic state at the surface of SrTiO3: importance of oxygen vacancies
• Atomic layer engineering of perovskite oxides for chemically sharp heterointerfaces
• Tuning up or down the critical thickness in LaAlO3/SrTiO3 through in situ deposition of metal overlayers
• Large Negative Electronic Compressibility of LaAlO3-SrTiO3 Interfaces with Ultrathin LaAlO3 Layers
• Termination control of electronic phases in oxide thin films and interfaces: LaAlO3/SrTiO3(001)
• Transport in strongly-coupled graphene-LaAlO3/SrTiO3 hybrid systems
• La interstitial defect-induced insulator-metal transition in oxide heterostructures LaAlO3/SrTiO3
• Large electropositive cations as surfactants for the growth of polar epitaxial films