Nonlinear properties of electron gas in n-InSb and graphene in THz range under finite temperatures

The nonlinear properties in THz range of 3D electron gas in narrow-gap n-InSb semiconductor and 2D one in graphene are investigated theoretically. The nonlinear dependencies of the density of electric current on the applied electric field have been computed from the kinetic approach under finite temperatures. A comparison has been done with the analytic dependencies obtained when an influence of the finite temperature was neglected. For n-InSb the nonlinear dependencies practically coincide with analytic ones, whereas for graphene there are some quantitative differences.