Dynamical Behaviour of Photoexcited Electron System in Gallium Arsenide

Abstract

In this work we report on the first observation of the far-infrared laser (119–220 μm) magneto-optical absorption by the photoexcited electron system in GaAs up to the magnetic field of 50 kG over the temperature range of 1.7–4.2 K. The major absorption lines observed for various samples are the 1s→2p₊₁ Zeeman transition and the cyclotron resonance of conduction electrons. It is found that both absorption line-widths are sensitive to impurity concentration and to conduction electron density. The magnitude of the electron-electron scattering and that of the electron-neutral impurity scattering under the quantum limit condition are thereby discussed.