Kinetics of intrasubband electron energy relaxation in quantum wells in a quantizing magnetic field

Abstract

Herein we report the intrasubband relaxation of electron energy in the Landau level system of quantum well as a function of magnetic field strength. The relative role of scattering processes contributing to relaxation kinetics, the electron-electron scattering which redistributes the electrons between Landau levels and the optical phonon emission by the electrons reaching the Landau levels lying near and above the optical phonon energy is revealed. It was shown the most important factor determining the kinetics of energy relaxation is the electron-electron scattering processes, delivering electrons to Landau levels close to optical phonon energy. The flux of these electrons depends on the number of the Landau levels lying below the energy of the optical phonon and increases substantially with a decrease in this number. On the contrary, the electron-phonon scattering rate dependence of the energy relaxation time was found to be much weaker.