  A number of intriguing properties emerge upon the formation of the epitaxial
interface between the insulating oxides LaAlO3 and SrTiO3. These properties,
which include a quasi two-dimensional conducting electron gas, low temperature
superconductivity, and magnetism, are not present in the bulk materials,
generating a great deal of interest in the fundamental physics of their
origins. While it is generally accepted that the novel behavior arises as a
result of a combination of electronic and atomic reconstructions and
growth-induced defects, the complex interplay between these effects remains
unclear. In this report, we review the progress that has been made towards
unraveling the complete picture of the SrTiO3/LaAlO3 interface, focusing
primarily on present ab initio theoretical work and its relation to the
experimental data. In the process, we highlight some key unresolved issues and
discuss how they might be addressed by future experimental and theoretical
studies.
