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 (1)

• Origin of charge density at LaAlO3-on-SrTiO3 hetero-interfaces; possibility of intrinsic doping

Cited by in corpus (2)

• Polar catastrophe and electronic reconstructions at the LaAlO3/SrTiO3 interface: evidence from optical second harmonic generation
• Electronic structure of the SrTiO${}_3$/LaAlO${}_3$ interface revealed by resonant soft x-ray scattering