Electron Mobility Non-Damping Fluctuations in Semiconductors

Abstract

Equilibrium state disturbance and restoration processes of an electron gas interacting with phonon system in an equilibrium semiconductor have been investigated. Damping peculiarities of small deviations (fluctuations) of electron system from equilibrium state due to electron-acoustic phonon random scattering have been analyzed. A second-order linear partial differential equation for symmetric component of fluctuation of electron distribution function was obtained via linearization of the Boltzmann equation. This equation describes the chaotic movement of electrons along the energy axis, which can be interpreted as diffusion in momentum space. Another equation which describes the time dependence of electron lattice mobility fluctuations was obtained. It was shown that in the Boltzmann equation linearization approximation, lattice mobility fluctuations do not decay over time. The time dependence of the mobility fluctuations is described by stochastic harmonic function with random amplitude and random initial phase.