Understanding the electronic, optical, and transport properties of (LaAlO$_3$)$_n$/(SrTiO$_3$)$_n$ multilayers

We examine the evolution of the electronic, optical, and transport properties of (LaAlO$_3$)$_n$/(SrTiO$_3$)$_n$ multilayers (where n denotes the number of unit cells) using density functional theory with local density approximations. Using an increasing supercell, we determine multiple properties for multilayers with increasing layer thickness (n). We show a critical thickness of about n = 4 will produce a shift in the conduction and the transport properties. This is most likely related to the pushing of electrons from the LaAlO$_3$ layer into the SrTiO$_3$ layer.