Title: Possible spin excitation structure in monolayer FeSe grown on SrTiO$_{3}$,
Abstract: Based on recent high-resolution angle-resolved photoemission spectroscopy
measurement in monolayer FeSe grown on SrTiO$_{3}$, we constructed a
tight-binding model and proposed a superconducting (SC) pairing function which
can well fit the observed band structure and SC gap anisotropy. Then we
investigated the spin excitation spectra in order to determine the possible
sign structure of the SC order parameter. We found that a resonance-like spin
excitation may occur if the SC order parameter changes sign along the Fermi
surfaces. However, this resonance is located at different locations in momentum
space compared to other FeSe-based superconductors, suggesting that the Fermi
surface shape and pairing symmetry in monolayer FeSe grown on SrTiO$_{3}$ may
be different from other FeSe-based superconductors.