Proposal for a bulk material based on a monolayer FeSe onSrTiO3high-temperature superconductor

Motivated by the high superconducting transition temperature of monolayer FeSe on ${\mathrm{SrTiO}}₃$, we propose a potential three-dimensional high-temperature superconductor superlattice FeSe-${\mathrm{SrTiO}}₃$ and study its structural stability and electronic structure using density functional theory. We find that the binding energy between the FeSe and ${\mathrm{SrTiO}}₃$ layers is about $\ensuremath{\sim}0.7$ eV per (${\mathrm{Fe}}₂{\mathrm{Se}}₂$) unit and that it saturates already within a single ${\mathrm{TiO}}₂$ atomic layer of ${\mathrm{SrTiO}}₃$. In addition we analyzed the dynamical stability of the superlattice and compared it to the case of bulk ${\mathrm{SrTiO}}₃$.