Origin of Metallic States at Heterointerface between Band Insulators LaAlO${}_3$ and SrTiO${}_3$

Abstract

We have studied the electronic structure at the heterointerface between the band insulators LaAlO${}_3$ and SrTiO${}_3$ using $insitu$ photoemission spectroscopy. Our experimental results clearly reveal the formation of a notched structure on the SrTiO${}_3$ side due to band bending at the metallic LaAlO${}_3$/TiO${}_2$-SrTiO${}_3$ interface. The structure, however, is absent at the insulating LaAlO${}_3$/SrO-SrTiO${}_3$ interface. The present results indicate that the metallic states originate not from the charge transfer through the interface on a short-range scale but from the accumulation of carriers on a long-range scale.

20 pages, 4 figures

References in corpus (5)

• High Mobility in LaAlO3/SrTiO3 Heterostructures: Origin, Dimensionality and Perspectives
• Origin of charge density at LaAlO3-on-SrTiO3 hetero-interfaces; possibility of intrinsic doping
• Photoemission from buried interfaces in SrTiO3/LaTiO3 superlattices
• Lattice polarization effects on electron-gas charge densities in ionic superlattices
• Electronic properties of buried hetero-interfaces of LaAlO3 on SrTiO3

Cited by in corpus (11)

• Surface defects and conduction in polar oxide heterostructures
• Polarity-induced oxygen vacancies at LaAlO3|SrTiO3 interfaces
• Polar catastrophe and electronic reconstructions at the LaAlO3/SrTiO3 interface: evidence from optical second harmonic generation
• Ferroelectric Dead Layer Driven by a Polar Interface
• Enhanced persistent photoconductivity in $\delta$-doped LaAlO${}_3$/SrTiO${}_3$ heterostructures
• Optically excited multi-band conduction in LaAlO3/SrTiO3 heterostructures
• Electronic structure of the SrTiO${}_3$/LaAlO${}_3$ interface revealed by resonant soft x-ray scattering
• Polaronic nature of a muonium-related paramagnetic center in SrTiO${}_3$
• Transport and thermoelectric properties of the LaAlO${}_3$/SrTiO${}_3$ interface
• In situ investigation of conducting interface formation in LaAlO3/SrTiO3 heterostructure
• General considerations of the electrostatic boundary conditions in oxide heterostructures