Nonresonant electronic Raman scattering in nonequilibrium.*

We apply a functional derivative method to calculate the nonresonant Raman scattering response function of nonequilibrium strongly correlated electrons in a pump-probe experiment. While we have already found an analytical expression for the nonresonant contribution to the electronic Raman scattering cross-section in the B_1g symmetry channel [1] (when the incident and scattered light are polarized perpendicular to each other), there is no direct way to do this for the case of the full symmetry of the lattice (the A_1g symmetry channel) because it requires computing time-dependent vertex correction (which are very challenging to compute in nonequilibrium). Instead, a functional derivative method enables us to determine the Raman response function in the A_1g symmetry channel numerically. For concreteness, we exploit the spinless Falicov-Kimball model, which is solved exactly in nonequilibrium within the dynamical mean-field theory. We calculate the nonresonant Raman scattering response function for different parameters of the model that define metallic and Mott-insulator phases in equilibrium.      

[1]. O. P. Matveev, A. M. Shvaika, T. P. Devereaux, J. K. Freericks, Phys. Rev. Lett. 122, 247402 (2019).