Acoustic plasmons in a two-component Fermi system

Abstract

The dispersion and line width of the longitudinal collective modes of a two-component degenerate Fermi-system (T=0) are obtained from the zeros of the dielectric function e(q,ω). The basis of our theory are kinetic equations for the distribution function including elastic electron-impurity scattering. Our results area) there is only one acoustic branchb) this mode is overdamped forq→0, andc) acoustic plasmons contribute only little to the energy loss-function (or the screened electron-ion and electron-electron potential).