  We show that electron-phonon coupling can induce strong electron pairing in
an FeSe monolayer on a SrTiO3 substrate (experimental indications for
superconducting Tc are between 65 and 109K). The role of the SrTiO3 substrate
in increasing the coupling is two-fold. First, the interaction of the FeSe and
TiO2 terminated face of SrTiO3 prevents the FeSe monolayer from undergoing a
shear-type (orthorhombic, nematic) structural phase transition. Second, the
substrate allows an anti-ferromagnetic ground state of FeSe which opens
electron-phonon coupling channels within the monolayer that are prevented by
symmetry in the non-magnetic phase. The spectral function for the
electron-phonon coupling (alpha2F) in our calculations agrees well with
inelastic tunneling data.
