Localization of Two-dimensional Electron Gas in LaAlO3/SrTiO3 Heterostructures

Abstract

We report strong localization of 2D electron gas in LaAlO3 / SrTiO3 epitaxial thin-film heterostructures grown on (LaAlO3)0.3-(Sr2AlTaO3)0.7 substrates by using pulsed laser deposition with in-situ reflection high-energy electron diffraction. Using longitudinal and transverse magnetotransport measurements, we have determined that disorder at the interface influences the conduction behavior, and that increasing the carrier concentration by growing at lower oxygen partial pressure changes the conduction from strongly localized at low carrier concentration to metallic at higher carrier concentration, with indications of weak localization. We interpret this behavior in terms of a changing occupation of Ti 3d bands near the interface, each with a different spatial extent and susceptibility to localization by disorder, and differences in carrier confinement due to misfit strain and point defects.

12 pages, 4 figures

References in corpus (6)

• Magnetic effects at the interface between nonmagnetic oxides
• High Mobility in LaAlO3/SrTiO3 Heterostructures: Origin, Dimensionality and Perspectives
• Origin of charge density at LaAlO3-on-SrTiO3 hetero-interfaces; possibility of intrinsic doping
• Polar catastrophe and electronic reconstructions at the LaAlO3/SrTiO3 interface: evidence from optical second harmonic generation
• Growth mode control of the free carrier density in SrTiO3-d films
• Strain phase diagram and domain orientation in SrTiO${}_3$ thin films

Cited by in corpus (12)

• Optically excited multi-band conduction in LaAlO3/SrTiO3 heterostructures
• Artificial two-dimensional polar metal by charge transfer to a ferroelectric insulator
• Fabricating Superconducting Interfaces between Artificially-Grown LaAlO${}_3$ and SrTiO${}_3$ Thin Films
• Bandgap Controlling of the Oxygen-Vacancy-Induced Two-Dimensional Electron Gas in SrTiO3
• Chemistry and structure of homoepitaxial SrTiO${}_3$ films and their influence on oxide-heterostructure interfaces
• Thermally excited multi-band conduction in LaAlO3/SrTiO3 heterostructures exhibiting magnetic scattering
• The Conducting Channel at the LaAlO${}_3$/SrTiO${}_3$ Interface
• Evolution of variable range hopping in strongly localized two dimensional electron gas at NdAlO3/SrTiO3 (100) heterointerfaces
• The mechanism of spin-orbit coupling in a 2D oxide interface
• Spin-orbit controlled quantum capacitance of a polar heterostructure
• Low temperature magnetoresistance of (111) (La${}_{0.3}$Sr${}_{0.7}$)(Al${}_{0.65}$Ta${}_{0.35}$)/SrTiO${}_3$
• Quantum oscillations in an optically-illuminated two-dimensional electron system at the LaAlO${}_3$/SrTiO${}_3$ interface