Proposal for a bulk material based on a monolayer FeSe on SrTiO3 high-temperature superconductor

TL;DR

This paper proposes a new three-dimensional superlattice structure based on monolayer FeSe on SrTiO3, aiming to explore high-temperature superconductivity through theoretical analysis of its stability and electronic properties.

Contribution

It introduces a novel FeSe-SrTiO3 superlattice structure and evaluates its structural and electronic stability using density functional theory.

Findings

Binding energy between layers is about 0.7 eV per unit.

Binding saturates within a single TiO2 layer.

Superlattice shows dynamical stability comparable to bulk SrTiO3.

Abstract

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.