Atomic-Scale Electronic Spectra across BiFeO$_{3}$/La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ Complex Oxide Heterointerfaces

Atomic-scale evolution of electronic structures across BiFeO$_{3}$/La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ complex oxide heterointerfaces has been revealed using cross-sectional scanning tunneling microscopy and spectroscopy. Analysis of scanning tunneling spectroscopy results exploits the interfacial valence mismatch to influence the electrostatic configurations across the BiFeO$_{3}$/La$_{0.7}$Sr$_{0.3}$MnO$_{0.3}$ heterointerfaces. Spatially unit-cell-by-unit-cell resolved electronic states at the atomic level reveal how the control of material interfaces at the atomic level to determine the ferroelectric polarization in BiFeO$_{3}$.