On the nature of carrier states around the fermi level at the LAO/STO interface

We propose a minimal tight-binding one-band model for the interface layer of LAO/STO consisting of “effective” carriers (of Ti-dxy character) in random magnetic fields. These fields result from the hybridization of Ti-d(e_g)-bands and oxygen vacancies at the LAO/STO interface and can be seen as local moments (i.e. “effective impurities”) located at the Ti-site. Both the effects of a nonmagnetic on-site potential and the exchange interactions (Zeeman like) between carrier and magnetic impurities are taken into account. We apply the coherent potential approximation in studying this system.