INELASTIC INTERACTION OF ELECTRONS WITH LATTICE WAVES IN MANY-VALLEY-MODEL SEMICONDUCTORS AT LOW-TEMPERATURE

The rate of loss of energy of nonequilibrium electrons due to inelasti c interactions with intravalley acoustic phonons in a high-purity many -valley model semiconductor has been calculated here under the conditi ons of low lattice temperature when the approximations of the well-kno wn traditional theory are not valid. The rate now depends upon the ave rage energy and the lattice temperature in a significantly different m anner compared to what follows from traditional approximations. The na ture of any such dependence is also different from that for the simple valley model unlike what the traditional theory predicts. Numerical r esults for Si and Ge show that the loss rates exceed the traditional v alues at lower energies for lower lattice temperatures.