1 research outputs found
Origin of charge density at LaAlO3-on-SrTiO3 hetero-interfaces; possibility of intrinsic doping
As discovered by Ohtomo et al., a large sheet charge density with high
mobility exists at the interface between SrTiO3 and LaAlO3. Based on transport,
spectroscopic and oxygen-annealing experiments, we conclude that extrinsic
defects in the form of oxygen vacancies introduced by the pulsed laser
deposition process used by all researchers to date to make these samples is the
source of the large carrier densities. Annealing experiments show a limiting
carrier density. We also present a model that explains the high mobility based
on carrier redistribution due to an increased dielectric constant.Comment: 14 pages, 3 figures, 1 table; accepted for publication in Phys. Rev.
Lett