ABSTRACT
This chapter theoretically examines the effect of carrier-carrier scattering (c-c scattering) processes on the intraband radiation absorption and their contribution to the net dynamic conductivity in optically or electrically pumped graphene. It demonstrates that the radiation absorption assisted by the c-c scattering is comparable with Drude absorption due to impurity scattering and is even stronger in sufficiently clean samples. The chapter derives the expression for the real part of the intraband dynamic conductivity (which is proportional to the intraband contribution to the radiation absorption) arising due to carrier-carrier collisions in clean pumped graphene. It derives the general equations for the radiation power absorbed due to c-c scattering-assisted intraband transitions, and finds the pertinent contribution to the dynamic conductivity. The chapter obtains the dependences of the intraband, interband, and net dynamic conductivity on the radiation frequency, the quasi-Fermi energy, the background dielectric constant; and finds the frequency threshold of the radiation amplification.
