摘要
In this study, direct observation of the evolution of electronic structures across complex oxide interfaces has been revealed in the LaAlO 3 /SrTiO 3 model system using cross-sectional scanning tunneling microscopy and spectroscopy. The conduction and valence band structures across the LaAlO 3 /SrTiO 3 interface are spatially resolved at the atomic level by measuring the local density of states. This study directly maps out the electronic reconstructions and a built-in electric field in the polar LaAlO 3 layer. Results also clearly reveal the band bending and the notched band structure in the SrTiO 3 adjacent to the interface. © 2012 American Physical Society.