Atomic-scale evolution of local electronic structure across multiferroic domain walls

Direct evidence of the electronic configurations across domain walls in BiFeO3 is quantitatively characterized by cross-sectional scanning tunneling microscopy. Atomic-scale band evolution and the asymmetrically built-in potential barrier at domain boundaries are demonstrated. The 109° domain walls register a remarkable decrease in the bandgap, suggesting a new route to control the local conducting channels within 2 nm. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.