Domain walls in strontium titanate

The crystal structure of SrTiO₃ transforms below 105 K from cubic to tetragonal. An applied gate voltage can be used to move the domains in samples with a thin epitaxial LaAlO₃ film. We present the atomic and electronic structure of domain walls in SrTiO₃ based on density functional calculations. We compute the effects of a LaAlO₃ film on the domains at the interface. We examine how doping at the interface modifies the domain structure. The importance of domains on electron pairing without superconductivity in this system will be discussed.