Atomic and electronic structure of twisted bilayers of SrTiO₃

Perovskite oxides are materials with chemical composition ABO3 in the unit cell. Thin films of perovskite oxides are desirable in many technologies due to their diverse structural, electrical, magnetic, and optical properties. Of particular interest are the correlated phases observed in the interfaces between thin films. We consider the dependence of the atomic and electronic structure of ultra thin film perovskite oxides on the relative twist angle between layers. In particular, we focus on twisted bilayers of SrTiO3, and derive DFT based analytic and continuum models that describe lattice relaxations and the electronic band structure, respectively. Finally, we investigate twist-induced strain as a source of octahedral tilting in the material.