The local electronic structure of the SrO-terminated SrTiO3(001) surface was explored using scanning tunneling microscopy. At low bias voltages in the empty states, a unidirectional structure with a periodicity of 3 unit cells, superimposed on a c(2 x 2) reconstructed structure, was found to develop along the crystallographic a axis. This structure indicates a charge-ordered stripe induced by carrier doping from oxygen vacancies in the SrO and the subsurface TiO2 planes. In the filled states, localized deep in-gap states were observed in addition to large energy gaps in the tunneling spectra. This result represents inelastic tunneling due to significant electron-lattice interaction associated with unidirectional lattice distortion in the SrO-terminated surface.
@article{arxiv.1102.0078,
title = {Stripe charge ordering in SrO-terminated SrTiO3(001) surfaces},
author = {Katsuya Iwaya and Ryota Shimizu and Takeo Ohsawa and Tomihiro Hashizume and Taro Hitosugi},
journal= {arXiv preprint arXiv:1102.0078},
year = {2015}
}
Comments
6 pages, 5 figures, accepted for publication in PRB