Calculations of the Absorption Coefficient of a Weak Electromagnetic Wave by Free Carriers in Quantum Wells by the Kubo-Mori Method
Analytic expressions for the absorption coefficient of a weak Electromagnetic Wave (EMW) by free carriers for the case of electron-optical phonon scattering in quantum wells are calculated by the Kubo-Mori method in two cases: - The absence of a magnetic field. - The presence of a magnetic field applied perpendicular to its barriers. A different dependence of the absorption coefficient on the temperature T of system, the electromagnetic wave frequency ω, the cyclotron frequency Ω (when a magnetic field is present), and characteristic parameters of a quantum well in comparison with normal semiconductors is obtained. The analytic expressions are numerically evaluated, plotted and discussed for a specific quantum well AlAs/GaAs/AlAs.