Second Order Nonlinear Dielectric Response of a Dynamic, Nonlocal Plasma Subject to Terahertz Radiation

We examine the nonlinear polarization of a solid state plasma in an incident terahertz (THz) field. In this, an iterated shielded potential approximation of the nonequilibrium Green’s function is employed to obtain the polarizability to second order in the THz field. This second order polarizability exhibits resonant behavior when the incident THz frequency matches the plasma frequency of the system, which can substantially reduce the effectiveness of screened impurity scattering potentials.