Several papers set up a model of fermions in 2D and calculate superconducting $T_c$, e.g.:
Superconductivity implies spontaneous symmetry breaking and as far as I can tell, the interactions in these papers are not long range. Why is not $T_c=0$ per the Mermin Wanger theorem?
These works actually try to model layered superconductors in 3D where MW doesn't apply, though the models they use are in 2D. Is 3Dness somehow implicitly incorporated into their calculatons in a way that allows for spontaneous symmetry breaking at finite $T$?