THE EFFECT OF THE NONPARABOLICITY OF THE FREE-CARRIERS DISPERSION LAWON THE PROPAGATION OF SURFACE-POLARITONS IN A SEMICONDUCTOR-METAL STRUCTURE

The results of a study on the influence of the nonparabolicity of the free carriers dispersion law on the propagation of surface polaritons (SPs) located near the interface between an n-type semiconductor and a metal are reported. The semiconductor plasma is assumed to be warm an d nonisothermal. The nonparabolicity of the electron dispersion law ha s two effects. The first one is associated with nonlinear self-interac tion of the SPs. The nonlinear dispersion equation and the nonlinear S chrodinger equation for the amplitude of the SP envelope are obtained. The nonlinear evolution of the SP is studied on the base of the above mentioned equations. The second effect results in third harmonics gen eration. Analysis shows that these third harmonics may appear as a pur e surface polariton, a pseudosurface polariton, or a superposition of a volume wave and a SP depending on the wave frequency, electron densi ty and lattice dielectric constant.