Ab initio study of the two-dimensional metallic state at the surface of SrTiO3: importance of oxygen vacancies

Abstract

Motivated by recent angle-resolved photoemission spectroscopy (ARPES) observations of a highly metallic two-dimensional electron gas (2DEG) at the (001) vacuum-cleaved surface of SrTiO3 and the subsequent discussion on the possible role of oxygen vacancies for the appearance of such a state (Ref 1), we analyze by means of density functional theory (DFT) the electronic structure of various oxygen-deficient SrTiO3 surface slabs. We find a significant surface reconstruction after introducing oxygen vacancies and we show that the charges resulting from surface-localized oxygen vacancies --independently of the oxygen concentration-- redistribute in the surface region and deplete rapidly within a few layers from the surface suggesting the formation of a 2DEG. We discuss the underlying model emerging from such observations.

References in corpus (12)

• Why Some Interfaces Cannot be Sharp
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• Creation and control of a two-dimensional electron liquid at the bare SrTiO3 surface
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• Interaction of W(CO)${}_6$ with SiO${}_2$ Surfaces -- A Density Functional Study

Cited by in corpus (20)

• Electron Correlation in Oxygen Vacancy in SrTiO${}_3$
• Persistent Optically Induced Magnetism in Oxygen-Deficient Strontium Titanate
• Magnetism, spin texture and in-gap states: Atomic specialization at the surface of oxygen-deficient SrTiO${}_3$
• Hubbard band or oxygen vacancy states in the correlated electron metal SrVO${}_3$?
• Localized versus itinerant states created by multiple oxygen vacancies in SrTiO3
• Emerging magnetism and electronic phase separation at titanate interfaces
• Topological states at the (001) surface of SrTiO3
• Electron correlation and magnetism at the LaAlO${}_3$/SrTiO${}_3$ interface: A DFT+DMFT investigation
• Electron dichotomy on the SrTiO${}_3$ defect surface augmented by many-body effects
• Spin-texture induced by oxygen vacancies in Strontium perovskites (001) surfaces: A theoretical comparison between SrTiO3 and SrHfO3
• Universal Structural Influence on the 2D Electron Gas at SrTiO${}_3$ Surfaces
• Oxygen-vacancy driven electron localization and itinerancy in rutile-based TiO${}_2$
• Controlling the magnetism of oxygen surface vacancies in strontium titanate $(\mathrm{SrTi}{\mathrm{O}}_3)$ through charging
• Interface exchange processes in LaAlO${}_3$/SrTiO${}_3$ induced by oxygen vacancies
• Oxygen vacancies and hydrogen doping in LaAlO3/SrTiO3 heterostructures: electronic properties and impact on surface and interface reconstruction
• 2D surprises at the surface of 3D materials: confined electron systems in transition metal oxides
• Electronic properties of the FeSe/STO interface from first-principle calculations
• Strong interplay between electron-phonon interaction and disorder in low doped systems
• Structure and ferromagnetic instability of the oxygen-deficient SrTiO${}_3$ surface
• Revealing Optically Induced Magnetization in SrTiO${}_3$ using Optically Coupled SQUID Magnetometry and Magnetic Circular Dichroism