Feasible model for light-induced interband pairing

Recent theoretical works have highlighted the existence of a purely electronic mechanism for the appearance of non-equilibrium superconductivity in a resonantly driven semiconductor with repulsive interband interactions. The original proposals relied anyway on the existence of a specific fermionic dissipation mechanism and the careful simultaneous tailoring of the electronic dispersion relation and the electron-electron interaction. In this work we show that this mechanism is actually more general and does not need any special tuning of the parameters. When considering a pair of bands with the same sign of concavity, we indeed demonstrate that interband pairing emerges under the natural assumptions of the presence of phononic baths and radiative recombination. In light of these findings, we show how the appearance of superconductivity can be understood in terms of standard equilibrium interband BCS theory. Finally, we conclude by presenting a phase diagram for the steady state of the model.