Superconducting dome in LaAlO3/SrTiO3 interfaces as a direct consequence of the extended s-wave symmetry of the gap

The two-dimensional electron gas (2DEG) at the ${\mathrm{LaAlO}}_{3}/{\mathrm{SrTiO}}_{3}$ interface exhibits gate-tunable superconductivity with a domelike shape of ${T}_{\mathrm{C}}$ as a function of electron concentration. Here, we propose that the experimentally observed behavior can be explained as a direct effect of the dominant $extended s\ensuremath{-}wave$ symmetry of the superconducting gap. Our results agree very well with the experimental data. As shown, neither the correlation effects nor the spin-orbit coupling significantly influence the physical picture of the paired state stemming from our analysis.