  Motivated by the high superconducting transition temperature of monolayer
FeSe on SrTiO3, we propose a potential three-dimensional high-temperature
superconductor superlattice FeSe-SrTiO3 and study its structural stability and
electronic structure using density functional theory. We find that the binding
energy between the FeSe and SrTiO3 layers is about 0.7 eV per (Fe2Se2) unit and
that it saturates already within a single TiO2 atomic layer of SrTiO3. In
addition we analyzed the dynamical stability of the superlattice and compared
it to the case of bulk SrTiO3.
