A First Principle Study of the LaAlO$_3$/SrTiO$_3$ Heterointerface

In order to understand the origin of the intriguing high mobility quasi two dimensional electron gas formed at the LaAlO$_3$/SrTiO$_3$(001) heterointerface, we carry out first principle calculations on the electronic structures and properties of complementary interface. The intrinsic polar properties are investigated and the average electronic potential increase by each LaAlO$_3$ layer is calculated, which can account for the recent observed experiment fact that the heterointerface is not metallic until the number of LaAlO$_3$ layers reaches a critical value. We also study the effects of different surface terminations of SrTiO$_3$ which surprisingly turn out to influence the electronic structure of the interface and so far have not been focused on in experiments.