Unusual Hole and Electron Midgap States and Orbital Reconstructions Induced Huge Ferroelectric Tunneling Electroresistance in BaTiO/SrTiO.

Oxide heterostructures have attracted a lot of interest because of their rich exotic phenomena and potential applications. Recently, a greatly enhanced tunneling electroresistance (TER) of ferroelectric tunnel junctions (FTJs) has been realized in such heterostructures. However, our understanding on the electronic structure of resistance response with polarization reversal and the origin of huge TER is still lacking.